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Ousmael KM, Cappa EP, Hansen JK, Hendre P, Hansen OK. Genomic evaluation for breeding and genetic management in Cordia africana, a multipurpose tropical tree species. BMC Genomics 2024; 25:9. [PMID: 38166623 PMCID: PMC10759591 DOI: 10.1186/s12864-023-09907-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/14/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Planting tested forest reproductive material is crucial to ensure the increased resilience of intensively managed productive stands for timber and wood product markets under climate change scenarios. Single-step Genomic Best Linear Unbiased Prediction (ssGBLUP) analysis is a cost-effective option for using genomic tools to enhance the accuracy of predicted breeding values and genetic parameter estimation in forest tree species. Here, we tested the efficiency of ssGBLUP in a tropical multipurpose tree species, Cordia africana, by partial population genotyping. A total of 8070 trees from three breeding seedling orchards (BSOs) were phenotyped for height. We genotyped 6.1% of the phenotyped individuals with 4373 single nucleotide polymorphisms. The results of ssGBLUP were compared with pedigree-based best linear unbiased prediction (ABLUP) and genomic best linear unbiased prediction (GBLUP), based on genetic parameters, theoretical accuracy of breeding values, selection candidate ranking, genetic gain, and predictive accuracy and prediction bias. RESULTS Genotyping a subset of the study population provided insights into the level of relatedness in BSOs, allowing better genetic management. Due to the inbreeding detected within the genotyped provenances, we estimated genetic parameters both with and without accounting for inbreeding. The ssGBLUP model showed improved performance in terms of additive genetic variance and theoretical breeding value accuracy. Similarly, ssGBLUP showed improved predictive accuracy and lower bias than the pedigree-based relationship matrix (ABLUP). CONCLUSIONS This study of C. africana, a species in decline due to deforestation and selective logging, revealed inbreeding depression. The provenance exhibiting the highest level of inbreeding had the poorest overall performance. The use of different relationship matrices and accounting for inbreeding did not substantially affect the ranking of candidate individuals. This is the first study of this approach in a tropical multipurpose tree species, and the analysed BSOs represent the primary effort to breed C. africana.
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Affiliation(s)
- Kedra M Ousmael
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958, Frederiksberg C, Denmark.
| | - Eduardo P Cappa
- Instituto Nacional de Tecnología Agropecuaria (INTA), Instituto de Recursos Biológicos, Centro de Investigación en Recursos Naturales, De Los Reseros y Dr. Nicolás Repetto s/n, 1686, Hurlingham, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Jon K Hansen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958, Frederiksberg C, Denmark
| | - Prasad Hendre
- World Agroforestry Centre (ICRAF), United Nations Avenue, Nairobi, 00100, Kenya
| | - Ole K Hansen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958, Frederiksberg C, Denmark
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2
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Omondi SF, Githae EW, Khasa DP. Long-distance gene flow in Acacia senegal: Hope for disturbed and fragmented populations. Ecol Evol 2023; 13:e10292. [PMID: 37449018 PMCID: PMC10337015 DOI: 10.1002/ece3.10292] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/23/2023] [Accepted: 06/29/2023] [Indexed: 07/18/2023] Open
Abstract
Even though pollen and seed dispersals are some of the important factors that determine tree species survival across landscapes, gene dispersal data of important tropical dryland tree species such as Acacia senegal that are undergoing various population disturbances remain scarce. Understanding patterns of gene dispersal in these ecosystems is important for conservation, landscape restoration and tree improvement. We investigated pollen and seed mediated gene flow in two A. senegal populations of contrasting state (less disturbed and heavily undisturbed) using nine microsatellites and 128 genotyping-by-sequencing single nucleotide polymorphism (SNPs) multilocus genotypes of two growth stages (juvenile and adult trees) and their spatial locations. We performed parentage assignments using likelihood approach and undertook spatial genetic structure (SGS) analyses for the two growth stages through correlation among kinship coefficients and geographical distances between pair of individuals. The SNPs showed higher resolving power and assignment rates than microsatellites; however, a combination of the two marker-types improved the assignment rate and provided robust parentage assessments. We found evidence of long-distance (up to 210 m) pollination events for both populations; however, the majority of seed dispersal was found closer to the putative maternal parent. On average, parentage analysis showed high amounts of pollen (40%) and seed (20%) immigration in both populations. Significant positive SGS was found only for the adult cohorts in the less disturbed population for distance classes 20 and 40 m, indicating historical short-distance seed dispersals. Our results suggest long-distance gene flow within the species and we recommend conservation of remnant and isolated populations or individual trees to promote genetic connectivity.
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Affiliation(s)
- Stephen F. Omondi
- Department of Forest Genetics and Tree ImprovementKenya Forestry Research InstituteNairobiKenya
| | | | - Damase P. Khasa
- Centre for Forest Research and Institute for Systems and Integrative BiologyUniversité LavalSainte‐FoyQuébecCanada
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3
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de Jesus Aguilar-Aguilar M, Cristobal-Pérez EJ, Lobo J, Fuchs EJ, Oyama K, Martén-Rodríguez S, Herrerías-Diego Y, Quesada M. Gone with the wind: Negative genetic and progeny fitness consequences of habitat fragmentation in the wind pollinated dioecious tree Brosimum alicastrum. AMERICAN JOURNAL OF BOTANY 2023; 110:e16157. [PMID: 36934453 DOI: 10.1002/ajb2.16157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 05/11/2023]
Abstract
PREMISE Habitat fragmentation negatively affects population size and mating patterns that directly affect progeny fitness and genetic diversity; however, little is known about the effects of habitat fragmentation on dioecious, wind pollinated trees. We assessed the effects of habitat fragmentation on population sex ratios, genetic diversity, gene flow, mating patterns, and early progeny vigor in the tropical dioecious tree, Brosimum alicastrum. METHODS We conducted our study in three continuous and three fragmented forest sites in a Mexican tropical dry forest. We used eight microsatellite loci to characterize the genetic diversity, gene flow via pollen distances, and mean relatedness of progeny. We compared early progeny vigor parameters of seedlings growing under greenhouse conditions. RESULTS Sex ratios did not deviate from 1:1 between habitat conditions except for one population in a fragmented habitat, which was female biased. The genetic diversity of adult trees and their offspring was similar in both habitat conditions. Pollen gene flow distances were similar across habitat types; however, paternity correlations were greater in fragmented than in continuous habitats. Germination rates did not differ between habitat conditions; however, progeny from fragmented habitats produced fewer leaves and had a lower foliar area, total height, and total dry biomass than progeny from continuous habitats. CONCLUSIONS Changes in mating patterns because of habitat fragmentation have negative effects on early progeny vigor. We conclude that negative habitat fragmentation effects on mating patterns and early progeny vigor may be a serious threat to the long-term persistence of tropical dioecious trees.
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Affiliation(s)
- Maria de Jesus Aguilar-Aguilar
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
| | - E Jacob Cristobal-Pérez
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
| | - Jorge Lobo
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Eric J Fuchs
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Ken Oyama
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
| | - Silvana Martén-Rodríguez
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
| | - Yvonne Herrerías-Diego
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México
| | - Mauricio Quesada
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
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Circa situm conservation of coffee agroforests: farmer’s perception in Kodagu landscape of Karnataka, India. Trop Ecol 2021. [DOI: 10.1007/s42965-021-00141-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Stacy EA, Sakishima T, Tharp H, Snow N. Isolation of Metrosideros ('Ohi'a) Taxa on O'ahu Increases with Elevation and Extreme Environments. J Hered 2021; 111:103-118. [PMID: 31844884 DOI: 10.1093/jhered/esz069] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 11/08/2019] [Indexed: 01/04/2023] Open
Abstract
Species radiations should be facilitated by short generation times and limited dispersal among discontinuous populations. Hawaii's hyper-diverse, landscape-dominant tree, Metrosideros, is unique among the islands' radiations for its massive populations that occur continuously over space and time within islands, its exceptional capacity for gene flow by both pollen and seed, and its extended life span (ca. >650 years). Metrosideros shows the greatest phenotypic and microsatellite DNA diversity on O'ahu, where taxa occur in tight sympatry or parapatry in mesic and montane wet forest on 2 volcanoes. We document the nonrandom distributions of 12 taxa (including unnamed morphotypes) along elevation gradients, measure phenotypes of ~6-year-old common-garden plants of 8 taxa to verify heritability of phenotypes, and examine genotypes of 476 wild adults at 9 microsatellite loci to compare the strengths of isolation across taxa, volcanoes, and distance. All 8 taxa retained their diagnostic phenotypes in the common garden. Populations were isolated by taxon to a range of degrees (pairwise FST between taxa: 0.004-0.267), and there was no pattern of isolation by distance or by elevation; however, significant isolation between volcanoes was observed within monotypic species, suggesting limited gene flow between volcanoes. Among the infraspecific taxa of Metrosideros polymorpha, genetic diversity and isolation significantly decreased and increased, respectively, with elevation. Overall, 5 of the 6 most isolated taxa were associated with highest elevations or otherwise extreme environments. These findings suggest a principal role for selection in the origin and maintenance of the exceptional diversity that occurs within continuous Metrosideros stands on O'ahu.
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Affiliation(s)
- Elizabeth A Stacy
- Department of Biology, University of Hawai'i Hilo, Hilo, HI.,Tropical Conservation Biology and Environmental Science Graduate Program, University of Hawai'i Hilo, Hilo, HI
| | - Tomoko Sakishima
- Department of Biology, University of Hawai'i Hilo, Hilo, HI.,Tropical Conservation Biology and Environmental Science Graduate Program, University of Hawai'i Hilo, Hilo, HI
| | - Heaven Tharp
- Department of Biology, University of Hawai'i Hilo, Hilo, HI
| | - Neil Snow
- Department of Biology, Pittsburg State University, Pittsburg, KS
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6
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Ferrer MM, Tapia-Gómez CA, Estrada-Medina H, Ruenes-Morales MDR, Montañez-Escalante PI, Jiménez-Osornio JJ. Growing Out of the Tropical Forests: Gene Flow of Native Mesoamerican Trees Among Forest and Mayan Homegardens. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.628765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
This work aimed to evaluate domestication effects on the genetic structure of two dioecious speciesBrosimum alicastrumSw. (Moraceae) andSpondias purpureaL. (Anacardiaceae), and a heterostylous oneCordia dodecandraA. DC. (Cordiaceae), growing in remnant forests and homegardens within two climatic regions of the Peninsula of Yucatan. The trees ofB. alicastrumandC. dodecandraare propagated by seeds in both population types, while those ofS. purpureaare propagated asexually in the homegardens. ISSRs genetic markers were amplified from foliar tissue of 18 to 21 plants per population type/region combination for each species. Genetic diversity, genetic differentiation, and genetic structure estimators were obtained and compared among species at the regional and population level. We found higher polymorphism (37.5–41), but lower private alleles (4–4.4) and similar heterozygosity (0.1–0.12) in the species with sexual reproduction compared toS. purpurea(34, 8, and 0.11, respectively). Genetic diversity inB. alicastrumpopulations varied with the region; inC. dodecandra, to the population type; and inS. purpurea, to both the population type and the region. Unrestricted gene flow among regions was suggested by low ΦRTinC. dodecandraandS. purpurea(−0.006 and 0.002) but not forB. alicastrum(0.1). Gene flow between populations within the regions for the sexually reproducing species was suggested by lower θII(0.005–0.07 and 0.008–0.1) estimates than those ofS. purpurea(0.09 and 0.13). Even though the lowest paired FST(0.002–0.05) and ΦST(0.002–0.12) values were found between the northeastern forest and homegarden populations for the three species, the dendrogram, Bayesian assignment, and K-Means analyses suggest that the least differentiated populations are southwestern forest and homegarden populations ofB. alicastrumandS. purpurea, and the southwestern forest and northeastern homegarden ofC. dodecandra. The sexual reproduction, biotic interactions, and extensive management ofB. alicastrumandC. dodecandrain the agroforestry and the urban systems may contribute to connectivity between wild and domesticated populations, while inS. purpureathis connectivity is interrupted by the clonal propagation of the species in the homegardens.
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7
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Millar MA, Coates DJ, Byrne M, Krauss SL, Jonson J, Hopper SD. Evaluating restoration outcomes through assessment of pollen dispersal, mating system, and genetic diversity. Restor Ecol 2021. [DOI: 10.1111/rec.13335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Melissa A. Millar
- Biodiversity and Conservation Science Department of Biodiversity Conservation and Attractions, Locked Bag 104, Bentley Delivery Centre Bentley WA 6983 Australia
- School of Biological Sciences, The University of Western Australia 35 Stirling Highway, Crawley WA 6009 Australia
| | - David J. Coates
- Biodiversity and Conservation Science Department of Biodiversity Conservation and Attractions, Locked Bag 104, Bentley Delivery Centre Bentley WA 6983 Australia
| | - Margaret Byrne
- Biodiversity and Conservation Science Department of Biodiversity Conservation and Attractions, Locked Bag 104, Bentley Delivery Centre Bentley WA 6983 Australia
- School of Biological Sciences, The University of Western Australia 35 Stirling Highway, Crawley WA 6009 Australia
| | - Siegfried L. Krauss
- School of Biological Sciences, The University of Western Australia 35 Stirling Highway, Crawley WA 6009 Australia
- Kings Park Science, Department of Biodiversity Conservation and Attractions Kattidj Close, Kings Park, WA 6005 Australia
| | - Justin Jonson
- Centre of Excellence in Natural Resource Management, School of Agriculture and the Environment, The University of Western Australia 35 Stirling Terrace, Albany WA 6330 Australia
| | - Stephen D. Hopper
- Centre of Excellence in Natural Resource Management, School of Agriculture and the Environment, The University of Western Australia 35 Stirling Terrace, Albany WA 6330 Australia
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8
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Zhou W, Zhang XX, Ren Y, Li P, Chen XY, Hu XS. Mating system and population structure in the natural distribution of Toona ciliata (Meliaceae) in South China. Sci Rep 2020; 10:16998. [PMID: 33046785 PMCID: PMC7550595 DOI: 10.1038/s41598-020-74123-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 09/23/2020] [Indexed: 11/15/2022] Open
Abstract
Most initially perfect flowers of Toona ciliata Roem subsequently develop into functionally unisexual flowers and their relative positions in the same inflorescence could enhance the outcrossing system in this species. Here we investigated the mating system of this species. We used eight nuclear microsatellite markers and investigated the progeny of 125 mother trees from six populations naturally distributed in South China, with sample sizes ranging from 64 to 300 seeds. The multilocus outcrossing rate was 0.970 ± 0.063, and the single locus outcrossing rate was 0.859 ± 0.106, indicating the pattern of predominant outcrossing. Selfing was present in one population, but biparental inbreeding occurred in five populations. Inbreeding was absent in maternal parents, and correlations of selfing among families or among loci were generally insignificant. Positive correlation of paternity at multiple loci was significant in four populations, but was not consistent with the results at single loci. Population substructure occurred in male similarity between outcrosses only in one population. Population genetic differentaitaion was significant (Fst = 34.5%) and the effects of isolation-by-distance at the eight loci were significant among the six populations. These results provide evidence that self-comptability and inbreeding naturally occur in T. ciliata and indicate that inbreeding avoidance is necessary during genetic improvement and breeding of this endangered tree species.
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Affiliation(s)
- Wei Zhou
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China.,Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Xin-Xin Zhang
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China.,Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Ying Ren
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China.,Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Pei Li
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China.,Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Xiao-Yang Chen
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China. .,Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China.
| | - Xin-Sheng Hu
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China. .,Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China.
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Zhang XX, Cheng X, Li LL, Wang X, Zhou W, Chen XY, Hu XS. The wave of gene advance under diverse systems of mating. Heredity (Edinb) 2020; 125:253-268. [PMID: 32606419 PMCID: PMC7490428 DOI: 10.1038/s41437-020-0333-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/09/2020] [Accepted: 06/09/2020] [Indexed: 11/09/2022] Open
Abstract
Mating systems will influence gene spread across the natural distribution of a plant species. Existing theories have not fully explored the role of mating systems on the wave of advance of an advantageous gene. Here, we develop a theory to account for the rate of spread of both advantageous and neutral genes under different mating systems, based on migration-selection processes. We show that a complex relationship exists between selfing rate and the speed of gene spread. The interaction of selfing with gametophytic selection shapes the traveling wave of the advantageous gene. Selfing can impede (or enhance) the spread of an advantageous gene in the presence (or absence) of gametophytic selection. The interaction of selfing with recombination shapes the spread of a neutral gene. Linkage disequilibrium, mainly generated by selfing, enhances the traveling wave of the neutral gene that is tightly linked with the selective gene. Recombination gradually breaks down the genetic hitchhiking effects along the direction of advantageous gene spread, yielding decreasing waves of advance of neutral genes. The stochastic process does not alter the pattern of selfing effects except for increasing the uncertainty of the waves of advance of both advantageous and neutral genes. This theory helps us to explain how mating systems act as a barrier to spread of adaptive and neutral genes, and to interpret species cohesion maintained by a low level of adaptive gene flow.
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Affiliation(s)
- Xin-Xin Zhang
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Xiang Cheng
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Ling-Ling Li
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Xi Wang
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Wei Zhou
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Xiao-Yang Chen
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China
| | - Xin-Sheng Hu
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangdong, 510642, China.
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangdong, 510642, China.
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The Pattern of Genetic Variation, Survival and Growth in the Abies alba Mill. Population within the Introgression Zone of Two Refugial Lineages in the Carpathians. FORESTS 2020. [DOI: 10.3390/f11080849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Objectives: The contact zones of different refugial lineages, where mixing of genetic backgrounds leads to new gene combinations or pre-adaptations, represent hotspots of genetic diversity. The aim of the study was to compare patterns in the genetic structure of the Abies alba Mill. population in the Eastern and Western Carpathians (Eastern Europe) within the introgression zone of two refugial lineages and the growth response of provenances located in a gradient of pollen-mediated gene fluxes. Materials and Methods: The mitochondrial nad5-4 marker and five polymorphic microsatellite nuclear markers (nSSR) were analyzed in 56 subpopulations from Romania, Ukraine, Slovakia and Poland. The survival rate and height growth up to an age of 15 years were compared for 33 subpopulations, forming a distance gradient between 170 and 470 km from the meeting zone of the refugial lineages. Results: The results of the analysis of molecular variance indicated that 8.2% of the total genetic variation is attributable to the between-subpopulation level and 1.7% to the between-lineage level. The pollen-mediated influence of the eastern lineage was detectable at a distance of at least 300 km in the western direction. Eastern provenances with origin sites closer to the meeting zone of the refugial lineages were characterized by lower survival rate and lower heights (about 8% lower than the average tree height) compared to subpopulations from the central and western part of the studied region. Conclusions: Pollen-mediated gene flow between lineages appears to have been sufficient to cause a significant change in phenotypic traits related to tree growth. Subpopulations from the central and western parts of the studied region are better adapted to current climatic conditions. Nonetheless, given the increasing aridity of the regional climate, a safe guideline is to increase genetic mixing.
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Cuénin N, Flores O, Rivière E, Lebreton G, Reynaud B, Martos F. Great Genetic Diversity but High Selfing Rates and Short-Distance Gene Flow Characterize Populations of a Tree (Foetidia; Lecythidaceae) in the Fragmented Tropical Dry Forest of the Mascarene Islands. J Hered 2020; 110:287-299. [PMID: 30726933 DOI: 10.1093/jhered/esy069] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 12/28/2018] [Indexed: 11/13/2022] Open
Abstract
Following the global trend of deforestation and degradation, tropical dry forests in the Mascarenes archipelago on Reunion has undergone harsh reduction and fragmentation within 3 centuries of human occupation. We investigated the genetic diversity, mating system, and gene flow in fragmented populations of the native tree Foetidia mauritiana (Lecythidaceae) on Reunion, using microsatellite genotyping of adults (in- and ex situ) and seed progenies (in situ only). To test genetic isolation between the Mascarene islands, we also genotyped conspecific adults on Mauritius, and trees of Foetidia rodriguesiana on Rodrigues. We found a high genetic diversity among the trees on Reunion, but no population structure (G'ST: 0.039-0.090), and an increase of the fixation index (FIS) from adults to progenies. A subsequent analysis of mating systems from progeny arrays revealed selfing rates >50% in fragmented populations and close to 100% in lone trees. A paternity analysis revealed pollen flow ranging from 15.6 to 296.1 m within fragments. At broader scale, the populations of F. mauritiana on Reunion and Mauritius are genetically differentiated. The morphologically allied taxa F. rodriguesiana and F. mauritiana are clearly isolated. Therefore, this case study shows that genetic diversity may persist after deforestation, especially in long-lived tree species, but the reproductive features may be deeply altered during this process. This would explain the low seed production and the absence of recruitment in F. mauritiana. Restoration programs should take into account these features, as well as the importance that trees ex situ represent in restoring and conserving diversity.
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Affiliation(s)
- Nicolas Cuénin
- CIRAD, UMR PVBMT, Saint-Pierre, La Réunion, France.,Université de La Réunion, UMR PVBMT, Saint-Pierre, La Réunion, France
| | - Olivier Flores
- Université de La Réunion, UMR PVBMT, Saint-Pierre, La Réunion, France
| | - Eric Rivière
- CIRAD, UMR PVBMT, Saint-Pierre, La Réunion, France
| | | | - Bernard Reynaud
- CIRAD, UMR PVBMT, Saint-Pierre, La Réunion, France.,Université de La Réunion, UMR PVBMT, Saint-Pierre, La Réunion, France
| | - Florent Martos
- Institut de Systématique, Evolution, Biodiversité (ISYEB), MNHN, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France
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12
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Caetano-Andrade VL, Clement CR, Weigel D, Trumbore S, Boivin N, Schöngart J, Roberts P. Tropical Trees as Time Capsules of Anthropogenic Activity. TRENDS IN PLANT SCIENCE 2020; 25:369-380. [PMID: 32037081 DOI: 10.1016/j.tplants.2019.12.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 12/03/2019] [Accepted: 12/09/2019] [Indexed: 06/10/2023]
Abstract
After the ice caps, tropical forests are globally the most threatened terrestrial environments. Modern trees are not just witnesses to growing contemporary threats but also legacies of past human activity. Here, we review the use of dendrochronology, radiocarbon analysis, stable isotope analysis, and DNA analysis to examine ancient tree management. These methods exploit the fact that living trees record information on environmental and anthropogenic selective forces during their own and past generations of growth, making trees living archaeological 'sites'. The applicability of these methods across prehistoric, historic, and industrial periods means they have the potential to detect evolving anthropogenic threats and can be used to set conservation priorities in rapidly vanishing environments.
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Affiliation(s)
| | | | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Susan Trumbore
- Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Nicole Boivin
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany; Department of Archaeology, University of Queensland, St Lucia QLD, 4072, Brisbane, Australia
| | - Jochen Schöngart
- Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brazil
| | - Patrick Roberts
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany; Department of Archaeology, University of Queensland, St Lucia QLD, 4072, Brisbane, Australia
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13
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Nakanishi A, Takeuchi T, Ueno S, Nishimura N, Tomaru N. Spatial variation in bird pollination and its mitigating effects on the genetic diversity of pollen pools accepted by Camellia japonica trees within a population at a landscape level. Heredity (Edinb) 2019; 124:170-181. [PMID: 31485029 DOI: 10.1038/s41437-019-0262-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 08/10/2019] [Accepted: 08/12/2019] [Indexed: 01/03/2023] Open
Abstract
Bird pollination can vary spatially in response to spatial fluctuations in flowering even within plant populations. In this study, we examined the hypothesis that the spatial variation in bird pollination may induce mitigating effects, which maintains or increases genetic diversity of pollen pools at local sites with low flowering densities. To test this hypothesis, we analyzed the landscape-level genetic effects within a population of Camellia japonica on the pollen pools accepted by individuals in two reproductive years by using genotypes at eight microsatellite loci of 1323 seeds from 19 seed parents. Regression analyses using the quadratic models of correlated paternity between pollen pools against spatial distances between the seed-parent pairs revealed not only local pollination but also some amount of long-distance pollen dispersal. The genetic diversity of pollen pools accepted by seed parents tended to be negatively related to the densities of flowering individuals near the seed parents during winter (when the effective pollination of C. japonica is mediated mostly by Zosterops japonica). We show that the low density of flowering individuals may induce the expansion of the foraging areas of Z. japonica and consequently increase the genetic diversity of pollen pools. This spatial variation in bird pollination may induce the mitigating effects on the C. japonica population. The comparisons between the two study years indicate that the overall pattern of bird pollination and the genetic effects described here, including the mitigating effects, may be stable over time.
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Affiliation(s)
- Atsushi Nakanishi
- Hokkaido Research Center, Forestry and Forest Products Research Institute, Forest Research and Management Organization, 7 Hitsujigaoka, Toyohira-ku, Sapporo, 062-8516, Japan
| | - Tomoe Takeuchi
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.,Forestry Department, Saku Regional Development Bureau, Nagano Prefectural Government, 65-1 Atobe, Saku, Nagano, 385-0054, Japan
| | - Saneyoshi Ueno
- Department of Forest Molecular Genetics and Biotechnology, Forestry and Forest Products Research Institute, Forest Research and Management Organization, 1 Matsunosato, Tsukuba, Ibaraki, 305-8687, Japan
| | - Naoyuki Nishimura
- Faculty of Social and Information Studies, Gunma University, 4-2 Aramaki-machi, Maebashi, Gunma, 371-8510, Japan
| | - Nobuhiro Tomaru
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
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14
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Murray B, Reid M, Capon S, Wu S. Genetic analysis suggests extensive gene flow within and between catchments in a common and ecologically significant dryland river shrub species; Duma florulenta (Polygonaceae). Ecol Evol 2019; 9:7613-7627. [PMID: 31346426 PMCID: PMC6635937 DOI: 10.1002/ece3.5310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 04/18/2019] [Accepted: 05/11/2019] [Indexed: 11/20/2022] Open
Abstract
AIM The conservation of plant species biodiversity has been identified as a crucial factor for the resilience of dryland ecosystems in the face of climate change and desertification. Duma florulenta (lignum) is a keystone species that facilitates biodiversity in the floodplains and wetlands of Australia's dryland river systems. This paper explores spatial genetic structure of lignum and investigates factors influencing dispersal and gene flow within and among river catchments of the northern Murray-Darling Basin. LOCATION Northern Murray-Darling Basin, eastern Australia. METHODS A total of 122 individual plants from subpopulations located on rivers in four adjacent catchments were genotyped using 10 microsatellite markers. Microsatellite data were then analyzed using population genetic techniques to evaluate levels of gene flow and genetic structure and identify factors influencing dispersal. RESULTS Results suggest high levels of gene flow between lignum subpopulations of the northern Murray-Darling Basin. AMOVA revealed small but significant differences between subpopulations, and STRUCTURE analysis did not detect meaningful structure when sampling information was not provided. However, when sampling information was supplied using the LOCPRIOR model, three genetic clusters were identified. All Lower Balonne subpopulations were assigned to cluster 1 while a number of the other subpopulations showed mixed ancestry. Weak relationships were identified between pairwise genetic distance and geographic as well as river distance, although the R 2 value of the former was only half that of the latter. MAIN CONCLUSIONS Patterns of genetic variation suggest frequent long-distance overland gene flow largely as a result of the movement of seeds via floodwater. Therefore, maintenance of natural variability in flow regime is key both to maintain conditions favorable to recruitment and to promote dispersal and gene flow across the landscape. However, given future climate change projections persistence may be more reliant on the species ability to endure long periods of drought between flood events.
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Affiliation(s)
- Bruce Murray
- Geography and Planning, Faculty of Humanities Arts and Social SciencesUniversity of New EnglandArmidaleNew South WalesAustralia
| | - Michael Reid
- Geography and Planning, Faculty of Humanities Arts and Social SciencesUniversity of New EnglandArmidaleNew South WalesAustralia
| | - Samantha Capon
- Australian Rivers InstituteGriffith UniversityNathanQueenslandAustralia
| | - Shu‐Biao Wu
- School of Environmental and Rural ScienceUniversity of New EnglandArmidaleNew South WalesAustralia
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15
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Aguilar R, Cristóbal‐Pérez EJ, Balvino‐Olvera FJ, Aguilar‐Aguilar M, Aguirre‐Acosta N, Ashworth L, Lobo JA, Martén‐Rodríguez S, Fuchs EJ, Sanchez‐Montoya G, Bernardello G, Quesada M. Habitat fragmentation reduces plant progeny quality: a global synthesis. Ecol Lett 2019; 22:1163-1173. [DOI: 10.1111/ele.13272] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/01/2019] [Accepted: 04/10/2019] [Indexed: 01/22/2023]
Affiliation(s)
- Ramiro Aguilar
- Instituto Multidisciplinario de Biología Vegetal Universidad Nacional de Córdoba –CONICET C.C. 495(X5000JJC)Córdoba Argentina
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
| | - Edson Jacob Cristóbal‐Pérez
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
| | - Francisco Javier Balvino‐Olvera
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
| | - María Aguilar‐Aguilar
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
| | - Natalia Aguirre‐Acosta
- Instituto Multidisciplinario de Biología Vegetal Universidad Nacional de Córdoba –CONICET C.C. 495(X5000JJC)Córdoba Argentina
| | - Lorena Ashworth
- Instituto Multidisciplinario de Biología Vegetal Universidad Nacional de Córdoba –CONICET C.C. 495(X5000JJC)Córdoba Argentina
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
| | - Jorge A. Lobo
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
- Escuela de Biología Universidad de Costa Rica San Pedro2600 Costa Rica
| | - Silvana Martén‐Rodríguez
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
| | - Eric J. Fuchs
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
- Escuela de Biología Universidad de Costa Rica San Pedro2600 Costa Rica
| | - Gumersindo Sanchez‐Montoya
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
| | - Gabriel Bernardello
- Instituto Multidisciplinario de Biología Vegetal Universidad Nacional de Córdoba –CONICET C.C. 495(X5000JJC)Córdoba Argentina
| | - Mauricio Quesada
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE) Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad Universidad Nacional Autónoma de México Morelia Michoacán 58190 México
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16
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Impact of habitat loss and fragmentation on reproduction, dispersal and species persistence for an endangered Chilean tree. CONSERV GENET 2019. [DOI: 10.1007/s10592-019-01187-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Chybicki IJ, Oleksa A. Seed and pollen gene dispersal in Taxus baccata, a dioecious conifer in the face of strong population fragmentation. ANNALS OF BOTANY 2018; 122:409-421. [PMID: 29873697 PMCID: PMC6311948 DOI: 10.1093/aob/mcy081] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 05/08/2018] [Indexed: 05/22/2023]
Abstract
Background and Aims Dispersal is crucial due to its direct impact on dynamics of a species' distribution as well as having a role in shaping adaptive potential through gene flow. In plants forming scarce and small populations, knowledge about the dispersal process is required to assess the potential for colonizing new habitats and connectivity of present and future populations. This study aimed to assess dispersal potential in Taxus baccata, a dioecious gymnosperm tree with a wide but highly fragmented distribution. Methods Seed and pollen dispersal kernels were estimated directly in the framework of the spatially explicit mating model, where genealogies of naturally established seedlings were reconstructed with the help of microsatellite markers. In this way, six differently shaped dispersal functions were compared. Key Results Seed dispersal followed a leptokurtic distribution, with the Exponential-Power, the Power-law and Weibull being almost equally best-fitting models. The pollen dispersal kernel appeared to be more fat-tailed than the seed dispersal kernel, and the Lognormal and the Exponential-Power function showed the best fit. The rate of seed immigration from the background sources was not significantly different from the rate of pollen immigration (13.1 % vs. 19.7 %) and immigration rates were in agreement with or below maximum predictions based on the estimated dispersal kernels. Based on the multimodel approach, 95 % of seeds travel <109 m, while 95 % of pollen travels <704 m from the source. Conclusions The results showed that, at a local spatial scale, yew seeds travel shorter distances than pollen, facilitating a rapid development of a kinship structure. At the landscape level, however, although yew exhibits some potential to colonize new habitats through seed dispersal, genetic connectivity between different yew remnants is strongly limited. Taking into account strong population fragmentation, the study suggests that gene dispersal may be a limiting factor of the adaptability of the species.
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Affiliation(s)
- Igor J Chybicki
- Department of Genetics, Institute of Experimental Biology, Kazimierz Wielki University, Bydgoszcz, Poland
| | - Andrzej Oleksa
- Department of Genetics, Institute of Experimental Biology, Kazimierz Wielki University, Bydgoszcz, Poland
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18
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Moraes MA, Kubota TYK, Rossini BC, Marino CL, Freitas MLM, Moraes MLT, da Silva AM, Cambuim J, Sebbenn AM. Long-distance pollen and seed dispersal and inbreeding depression in Hymenaea stigonocarpa (Fabaceae: Caesalpinioideae) in the Brazilian savannah. Ecol Evol 2018; 8:7800-7816. [PMID: 30250664 PMCID: PMC6144967 DOI: 10.1002/ece3.4253] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 03/02/2018] [Accepted: 05/14/2018] [Indexed: 02/03/2023] Open
Abstract
Hymenaea stigonocarpa is a neotropical tree that is economically important due to its high-quality wood; however, because it has been exploited extensively, it is currently considered threatened. Microsatellite loci were used to investigate the pollen and seed dispersal, mating patterns, spatial genetic structure (SGS), genetic diversity, and inbreeding depression in H. stigonocarpa adults, juveniles, and open-pollinated seeds, which were sampled from isolated trees in a pasture and trees within a forest fragment in the Brazilian savannah. We found that the species presented a mixed mating system, with population and individual variations in the outcrossing rate (0.53-1.0). The studied populations were not genetically isolated due to pollen and seed flow between the studied populations and between the populations and individuals located outside of the study area. Pollen and seed dispersal occurred over long distances (>8 km); however, the dispersal patterns were isolated by distance, with a high frequency of mating occurring between near-neighbor trees and seeds dispersed near the parent trees. The correlated mating for individual seed trees was higher within than among fruits, indicating that fruits present a high proportion of full-sibs. Genetic diversity and SGS were similar among the populations, but offspring showed evidence of inbreeding, mainly originating from mating among related trees, which suggests inbreeding depression between the seed and adult stages. Selfing resulted in a higher inbreeding depression than mating among relatives, as assessed through survival and height. As the populations are not genetically isolated, both are important targets for in situ conservation to maintain their genetic diversity; for ex situ conservation, seeds can be collected from at least 78 trees in both populations separated by at least 250 m.
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Affiliation(s)
| | | | | | | | | | | | | | - Jose Cambuim
- Faculdade de Engenharia de Ilha Solteira/UNESPIlha SolteiraSPBrazil
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19
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Browne L, Karubian J. Habitat loss and fragmentation reduce effective gene flow by disrupting seed dispersal in a neotropical palm. Mol Ecol 2018; 27:3055-3069. [DOI: 10.1111/mec.14765] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 06/04/2018] [Accepted: 06/05/2018] [Indexed: 01/22/2023]
Affiliation(s)
- Luke Browne
- Department of Ecology and Evolutionary Biology Tulane University New Orleans Louisiana
- Foundation for the Conservation of the Tropical Andes Quito Ecuador
- UCLA La Kretz Center for California Conservation Science Institute of the Environment and Sustainability University of California Los Angeles California
| | - Jordan Karubian
- Department of Ecology and Evolutionary Biology Tulane University New Orleans Louisiana
- Foundation for the Conservation of the Tropical Andes Quito Ecuador
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20
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Llorens TM, Yates CJ, Byrne M, Elliott CP, Sampson J, Fairman R, Macdonald B, Coates DJ. Altered Soil Properties Inhibit Fruit Set but Increase Progeny Performance for a Foundation Tree in a Highly Fragmented Landscape. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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21
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Hartvig I, So T, Changtragoon S, Tran HT, Bouamanivong S, Theilade I, Kjær ED, Nielsen LR. Population genetic structure of the endemic rosewoods Dalbergia cochinchinensis and D. oliveri at a regional scale reflects the Indochinese landscape and life-history traits. Ecol Evol 2017; 8:530-545. [PMID: 29321891 PMCID: PMC5756888 DOI: 10.1002/ece3.3626] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/29/2017] [Accepted: 10/11/2017] [Indexed: 11/12/2022] Open
Abstract
Indochina is a biodiversity hot spot and harbors a high number of endemic species, most of which are poorly studied. This study explores the genetic structure and reproductive system of the threatened endemic timber species Dalbergia cochinchinensis and Dalbergia oliveri using microsatellite data from populations across Indochina and relates it to landscape characteristics and life‐history traits. We found that the major water bodies in the region, Mekong and Tonle Sap, represented barriers to gene flow and that higher levels of genetic diversity were found in populations in the center of the distribution area, particularly in Cambodia. We suggest that this pattern is ancient, reflecting the demographic history of the species and possible location of refugia during earlier time periods with limited forest cover, which was supported by signs of old genetic bottlenecks. The D. oliveri populations had generally high levels of genetic diversity (mean He = 0.73), but also strong genetic differentiation among populations (global GST = 0.13), while D. cochinchinensis had a moderate level of genetic diversity (mean He = 0.55), and an even stronger level of differentiation (global GST = 0.25). These differences in genetic structure can be accounted for by a higher level of gene flow in D. oliveri due to a higher dispersal capacity, but also by the broader distribution area for D. oliveri, and the pioneer characteristics of D. cochinchinensis. This study represents the first detailed analysis of landscape genetics for tree species in Indochina, and the found patterns might be common for other species with similar ecology.
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Affiliation(s)
- Ida Hartvig
- Department of Geosciences and Natural Resource Management University of Copenhagen Frederiksberg C Denmark
| | - Thea So
- Institute of Forest and Wildlife Research and Development, Forestry Administration Ministry of Agriculture, Forestry and Fisheries Phnom Penh Cambodia
| | - Suchitra Changtragoon
- Forest and Plant Conservation Research Office Department of National Parks, Wildlife and Plant Conservation Ministry of Natural Resources and Environment Chatuchak, Bangkok Thailand
| | - Hoa Thi Tran
- Forest Genetics and Conservation Center for Biodiversity and Biosafety Institute of Agricultural Genetics Vietnam Academy of Agricultural Sciences Hanoi Vietnam
| | - Somsanith Bouamanivong
- National Herbarium of Laos Biotechnology and Ecology Institute Ministry of Science and Technology Vientiane Laos
| | - Ida Theilade
- Department of Food and Resource Economics University of Copenhagen Frederiksberg C Denmark
| | - Erik Dahl Kjær
- Department of Geosciences and Natural Resource Management University of Copenhagen Frederiksberg C Denmark
| | - Lene Rostgaard Nielsen
- Department of Geosciences and Natural Resource Management University of Copenhagen Frederiksberg C Denmark
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22
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Semizer-Cuming D, Kjær ED, Finkeldey R. Gene flow of common ash (Fraxinus excelsior L.) in a fragmented landscape. PLoS One 2017; 12:e0186757. [PMID: 29053740 PMCID: PMC5650178 DOI: 10.1371/journal.pone.0186757] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 10/06/2017] [Indexed: 12/24/2022] Open
Abstract
Gene flow dynamics of common ash (Fraxinus excelsior L.) is affected by several human activities in Central Europe, including habitat fragmentation, agroforestry expansion, controlled and uncontrolled transfer of reproductive material, and a recently introduced emerging infectious disease, ash dieback, caused by Hymenoscyphus fraxineus. Habitat fragmentation may alter genetic connectivity and effective population size, leading to loss of genetic diversity and increased inbreeding in ash populations. Gene flow from cultivated trees in landscapes close to their native counterparts may also influence the adaptability of future generations. The devastating effects of ash dieback have already been observed in both natural and managed populations in continental Europe. However, potential long-term effects of genetic bottlenecks depend on gene flow across fragmented landscapes. For this reason, we studied the genetic connectivity of ash trees in an isolated forest patch of a fragmented landscape in Rösenbeck, Germany. We applied two approaches to parentage analysis to estimate gene flow patterns at the study site. We specifically investigated the presence of background pollination at the landscape level and the degree of genetic isolation between native and cultivated trees. Local meteorological data was utilized to understand the effect of wind on the pollen and seed dispersal patterns. Gender information of the adult trees was considered for calculating the dispersal distances. We found that the majority of the studied seeds (55-64%) and seedlings (75-98%) in the forest patch were fathered and mothered by the trees within the same patch. However, we determined a considerable amount of pollen flow (26-45%) from outside of the study site, representing background pollination at the landscape level. Limited pollen flow was observed from neighbouring cultivated trees (2%). Both pollen and seeds were dispersed in all directions in accordance with the local wind directions. Whereas there was no positive correlation between pollen dispersal distance and wind speed, the correlation between seed dispersal distance and wind speed was significant (0.71, p < 0.001), indicating that strong wind favours long-distance dispersal of ash seeds. Finally, we discussed the implications of establishing gene conservation stands and the use of enrichment planting in the face of ash dieback.
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Affiliation(s)
- Devrim Semizer-Cuming
- Department of Forest Genetics and Forest Tree Breeding, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Göttingen, Germany
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Erik Dahl Kjær
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Reiner Finkeldey
- Department of Forest Genetics and Forest Tree Breeding, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Göttingen, Germany
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Dávila-Lara A, Affenzeller M, Tribsch A, Díaz V, Comes HP. AFLP diversity and spatial structure of Calycophyllum candidissimum (Rubiaceae), a dominant tree species of Nicaragua's critically endangered seasonally dry forest. Heredity (Edinb) 2017; 119:275-286. [PMID: 28767103 PMCID: PMC5597786 DOI: 10.1038/hdy.2017.45] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 05/30/2017] [Accepted: 06/16/2017] [Indexed: 11/08/2022] Open
Abstract
The Central American seasonally dry tropical (SDT) forest biome is one of the worlds' most endangered ecosystems, yet little is known about the genetic consequences of its recent fragmentation. A prominent constituent of this biome is Calycophyllum candidissimum, an insect-pollinated and wind-dispersed canopy tree of high socio-economic importance, particularly in Nicaragua. Here, we surveyed amplified fragment length polymorphisms across 13 populations of this species in Nicaragua to elucidate the relative roles of contemporary vs historical factors in shaping its genetic variation. Genetic diversity was low in all investigated populations (mean HE=0.125), and negatively correlated with latitude. Overall population differentiation was moderate (ΦST=0.109, P<0.001), and Bayesian analysis of population structure revealed two major latitudinal clusters (I: 'Pacific North'+'Central Highland'; II: 'Pacific South'), along with a genetic cline between I and II. Population-based cluster analyses indicated a strong pattern of 'isolation by distance' as confirmed by Mantel's test. Our results suggest that (1) the low genetic diversity of these populations reflects biogeographic/population history (colonisation from South America, Pleistocene range contractions) rather than recent human impact; whereas (2) the underlying process of their isolation by distance pattern, which is best explained by 'isolation by dispersal limitation', implies contemporary gene flow between neighbouring populations as likely facilitated by the species' efficient seed dispersal capacity. Overall, these results underscore that even tree species from highly decimated forest regions may be genetically resilient to habitat fragmentation due to species-typical dispersal characteristics, the necessity of broad-scale measures for their conservation notwithstanding.
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Affiliation(s)
- A Dávila-Lara
- Departamento de Biología, Universidad Nacional Autónoma de Nicaragua-León (UNAN), León, Nicaragua
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - M Affenzeller
- Department of Ecology and Evolution, University of Salzburg, Salzburg, Austria
| | - A Tribsch
- Department of Ecology and Evolution, University of Salzburg, Salzburg, Austria
| | - V Díaz
- Departamento de Biología, Universidad Nacional Autónoma de Nicaragua-León (UNAN), León, Nicaragua
| | - H P Comes
- Department of Ecology and Evolution, University of Salzburg, Salzburg, Austria
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24
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Monthe FK, Hardy OJ, Doucet JL, Loo J, Duminil J. Extensive seed and pollen dispersal and assortative mating in the rain forest tree Entandrophragma cylindricum (Meliaceae) inferred from indirect and direct analyses. Mol Ecol 2017; 26:5279-5291. [PMID: 28734064 DOI: 10.1111/mec.14241] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/17/2017] [Accepted: 07/05/2017] [Indexed: 02/02/2023]
Abstract
Pollen and seed dispersal are key processes affecting the demographic and evolutionary dynamics of plant species and are also important considerations for the sustainable management of timber trees. Through direct and indirect genetic analyses, we studied the mating system and the extent of pollen and seed dispersal in an economically important timber species, Entandrophragma cylindricum (Meliaceae). We genotyped adult trees, seeds and saplings from a 400-ha study plot in a natural forest from East Cameroon using eight nuclear microsatellite markers. The species is mainly outcrossed (t = 0.92), but seeds from the same fruit are often pollinated by the same father (correlated paternity, rp = 0.77). An average of 4.76 effective pollen donors (Nep ) per seed tree contributes to the pollination. Seed dispersal was as extensive as pollen dispersal, with a mean dispersal distance in the study plot approaching 600 m, and immigration rates from outside the plot to the central part of the plot reaching 40% for both pollen and seeds. Extensive pollen- and seed-mediated gene flow is further supported by the weak, fine-scale spatial genetic structure (Sp statistic = 0.0058), corresponding to historical gene dispersal distances (σg ) reaching approximately 1,500 m. Using an original approach, we showed that the relatedness between mating individuals (Fij = 0.06) was higher than expected by chance, given the extent of pollen dispersal distances (expected Fij = 0.02 according to simulations). This remarkable pattern of assortative mating could be a phenomenon of potentially consequential evolutionary and management significance that deserves to be studied in other plant populations.
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Affiliation(s)
- Franck Kameni Monthe
- Bioversity International, c/o CIFOR Central Africa Regional Office, Yaoundé, Cameroon.,Faculté des Sciences, Service Evolution Biologique et Ecologie, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Olivier J Hardy
- Faculté des Sciences, Service Evolution Biologique et Ecologie, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Jean-Louis Doucet
- Foresterie Tropicale, Gestion des Ressources Forestières, BIOSE, Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgium
| | - Judy Loo
- Bioversity International, Rome, Italy
| | - Jérôme Duminil
- Bioversity International, c/o CIFOR Central Africa Regional Office, Yaoundé, Cameroon.,Faculté des Sciences, Service Evolution Biologique et Ecologie, Université Libre de Bruxelles, Bruxelles, Belgium.,Institut de Recherche pour le Développement, UMR-DIADE, Montpellier, France
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Genetic diversity and structure of the treeManilkara zapotain a naturally fragmented tropical forest. JOURNAL OF TROPICAL ECOLOGY 2017. [DOI: 10.1017/s0266467417000268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract:Forest fragmentation, habitat loss and isolation may have a strong effect on biodiversity in tropical forests. This can include modification of the genetic diversity and structure of plant populations. In this study, we assessed the genetic diversity and structure of the treeManilkara zapotain 15 naturally formed fragments of semi-evergreen tropical forest, as well as in an adjacent continuous forest for comparison. Forest fragments were scattered within a matrix of wetlands and were highly variable in terms of size and degree of isolation. The naturally fragmented populations ofM.zapotahad slightly less allelic diversity (Ar: 3.4) than those of the continuous forest (Ar: 3.6), when corrected for sample size. However, populations in the fragments and continuous forest had very similar heterozygosity levels (HE: 0.59 in both cases). Low levels of genetic differentiation were observed among populations (FST: 0.026) and genetic structure was not consistent with isolation by distance, indicating high levels of gene flow. Genetic diversity was not explained by fragment size or degree of isolation. The relatively high genetic diversity and low inter-population genetic differentiation observed inM. zapotamay be the result of long-distance pollen and seed dispersal, as well as the high proximity among patches.
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Giombini MI, Bravo SP, Sica YV, Tosto DS. Early genetic consequences of defaunation in a large-seeded vertebrate-dispersed palm (Syagrus romanzoffiana). Heredity (Edinb) 2017; 118:568-577. [PMID: 28121308 PMCID: PMC5436022 DOI: 10.1038/hdy.2016.130] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 12/14/2016] [Accepted: 12/15/2016] [Indexed: 11/08/2022] Open
Abstract
Plant populations are seriously threatened by anthropogenic habitat disturbance. In particular, defaunation may disrupt plant-disperser mutualisms, thus reducing levels of seed-mediated gene flow and genetic variation in animal-dispersed plants. This may ultimately limit their adaptive potential and ability to cope with environmental change. Tropical forest remnants are typically deprived of medium to large vertebrates upon which many large-seeded plants rely for accomplishing effective seed dispersal. Our main goal was to examine the potential early genetic consequences of the loss of large vertebrates for large-seeded vertebrate-dispersed plants. We compared the genetic variation in early-stage individuals of the large-seeded palm Syagrus romanzoffiana between continuous protected forest and nearby partially defaunated fragments in the Atlantic Forest of South America. Using nine microsatellites, we found lower allelic richness and stronger fine-scale spatial genetic structure in the disturbed area. In addition, the percentage of dispersed recruits around conspecific adults was lower, although not significantly, in the disturbed area (median values: 0.0 vs 14.4%). On the other hand, no evidence of increased inbreeding or reduced pollen-mediated gene flow (selfing rate and diversity of pollen donors) was found in the disturbed area. Our findings are strongly suggestive of some early genetic consequences resulting from the limitation in contemporary gene flow via seeds, but not pollen, in defaunated areas. Plant-disperser mutualisms involving medium-large frugivores, which are seriously threatened in tropical systems, should therefore be protected to warrant the maintenance of seed-mediated gene flow and genetic diversity in large-seeded plants.
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Affiliation(s)
- M I Giombini
- IEGEBA, Instituto de Ecología, Genética y Evolución de Buenos Aires, UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
- Instituto de Biotecnología, Instituto Nacional de Tecnología Agropecuaria INTA-Castelar, Hurlingham, Buenos Aires, Argentina
| | - S P Bravo
- IEGEBA, Instituto de Ecología, Genética y Evolución de Buenos Aires, UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Y V Sica
- IEGEBA, Instituto de Ecología, Genética y Evolución de Buenos Aires, UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - D S Tosto
- Instituto de Biotecnología, Instituto Nacional de Tecnología Agropecuaria INTA-Castelar, Hurlingham, Buenos Aires, Argentina
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Chen Y, Liu Y, Fan X, Li W, Liu Y. Landscape-Scale Genetic Structure of Wild Rice Zizania latifolia: The Roles of Rivers, Mountains and Fragmentation. Front Ecol Evol 2017. [DOI: 10.3389/fevo.2017.00017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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28
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Potential Population Genetic Consequences of Habitat Fragmentation in Central European Forest Trees and Associated Understorey Species—An Introductory Survey. DIVERSITY 2017. [DOI: 10.3390/d9010009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Peng Y, Morales L, Hensen I, Renison D. No effect of elevation and fragmentation on genetic diversity and structure inPolylepis australistrees from central Argentina. AUSTRAL ECOL 2016. [DOI: 10.1111/aec.12432] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yanling Peng
- Institute of Biology/Geobotany and Botanical Garden; Martin Luther University of Halle-Wittenberg; Halle/Saale Germany
| | - Laura Morales
- Department of Plant Sciences and Graduate Group in Ecology; University of California; Davis California USA
| | - Isabell Hensen
- Institute of Biology/Geobotany and Botanical Garden; Martin Luther University of Halle-Wittenberg; Halle/Saale Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Leipzig Germany
| | - Daniel Renison
- Instituto de Investigaciones Biológicas y Tecnológicas; Centro de Ecología y Recursos Naturales Renovables (CONICET - Universidad Nacional de Córdoba); Córdoba Argentina
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Omondi SF, Odee DW, Ongamo GO, Kanya JI, Khasa DP. Genetic consequences of anthropogenic disturbances and population fragmentation in Acacia senegal. CONSERV GENET 2016. [DOI: 10.1007/s10592-016-0854-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Gene flow and fine-scale spatial genetic structure in Cabralea canjerana (Meliaceae), a common tree species from the Brazilian Atlantic forest. JOURNAL OF TROPICAL ECOLOGY 2016. [DOI: 10.1017/s0266467416000067] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract:The Atlantic forest is the biome most severely affected by deforestation in Brazil. Cabralea canjerana spp. canjerana is a dioecious tree species with widespread distribution in the Neotropical region. This species is considered a model to ascertain population ecology parameters for endangered plant species from the Atlantic forest. Fine-scale spatial genetic structure and pollen-mediated gene flow are crucial information in landscape genetics and evolutionary ecology. A total of 192 adults and 121 offspring were sampled in seven C. canjerana populations in the Southern Minas Gerais State, Brazil, to assess whether pollen-mediated gene flow is able to prevent spatial genetic structure within and among Atlantic forest fragments. Several molecular ecology parameters were estimated using microsatellite loci. High levels of genetic diversity (HE = 0.732) and moderate population structure (θ = 0.133) were recorded. No significant association between kinship and spatial distance amongst individuals within each population (Sp = 0.000109) was detected. Current pollen-mediated gene flow occurs mainly within forest fragments, probably due to short-distance flights of the pollinator of C. canjerana, and also the forest fragmentation may have restricted flight distance. The high levels of genetic differentiation found amongst the seven sites sampled demonstrated how habitat fragmentation affects the gene flow process in natural areas.
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Relationships between population density, fine-scale genetic structure, mating system and pollen dispersal in a timber tree from African rainforests. Heredity (Edinb) 2015; 116:295-303. [PMID: 26696137 PMCID: PMC4806568 DOI: 10.1038/hdy.2015.101] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 10/07/2015] [Accepted: 10/07/2015] [Indexed: 11/09/2022] Open
Abstract
Owing to the reduction of population density and/or the environmental changes it induces, selective logging could affect the demography, reproductive biology and evolutionary potential of forest trees. This is particularly relevant in tropical forests where natural population densities can be low and isolated trees may be subject to outcross pollen limitation and/or produce low-quality selfed seeds that exhibit inbreeding depression. Comparing reproductive biology processes and genetic diversity of populations at different densities can provide indirect evidence of the potential impacts of logging. Here, we analysed patterns of genetic diversity, mating system and gene flow in three Central African populations of the self-compatible legume timber species Erythrophleum suaveolens with contrasting densities (0.11, 0.68 and 1.72 adults per ha). The comparison of inbreeding levels among cohorts suggests that selfing is detrimental as inbred individuals are eliminated between seedling and adult stages. Levels of genetic diversity, selfing rates (∼16%) and patterns of spatial genetic structure (Sp ∼0.006) were similar in all three populations. However, the extent of gene dispersal differed markedly among populations: the average distance of pollen dispersal increased with decreasing density (from 200 m in the high-density population to 1000 m in the low-density one). Overall, our results suggest that the reproductive biology and genetic diversity of the species are not affected by current logging practices. However, further investigations need to be conducted in low-density populations to evaluate (1) whether pollen limitation may reduce seed production and (2) the regeneration potential of the species.
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The resilience of forest fragmentation genetics--no longer a paradox--we were just looking in the wrong place. Heredity (Edinb) 2015; 115:97-9. [PMID: 26176685 DOI: 10.1038/hdy.2015.40] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Martins K, Kimura RK, Francisconi AF, Gezan S, Kainer K, Christianini AV. The role of very small fragments in conserving genetic diversity of a common tree in a hyper fragmented Brazilian Atlantic forest landscape. CONSERV GENET 2015. [DOI: 10.1007/s10592-015-0800-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Tambarussi EV, Boshier D, Vencovsky R, Freitas MLM, Sebbenn AM. Paternity analysis reveals significant isolation and near neighbor pollen dispersal in small Cariniana legalis Mart. Kuntze populations in the Brazilian Atlantic Forest. Ecol Evol 2015; 5:5588-600. [PMID: 27069608 PMCID: PMC4813111 DOI: 10.1002/ece3.1816] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 10/06/2015] [Accepted: 10/09/2015] [Indexed: 11/09/2022] Open
Abstract
Throughout the world, large trees are increasingly rare. Cariniana legalis is the tallest tree species of the Brazilian Atlantic Forest, reaching up to 60 m in height. Due to extensive deforestation of the Atlantic Forest, remnant C. legalis populations are small and spatially isolated, requiring the development of strategies for their conservation. For in situ and ex situ genetic conservation to be effective, it is important to understand the levels and patterns of spatial genetic structure (SGS), and gene flow. We investigated SGS and pollen flow in three small, physically isolated C. legalis stands using microsatellite loci. We measured, mapped, and sampled all C. legalis trees in the three stands: 65 trees from Ibicatu population, 22 trees from MGI, and 4 trees from MGII. We also collected and genotyped 600 seeds from Ibicatu, 250 seeds from MGI, and 200 seeds from MGII. Significant SGS was detected in Ibicatu up to 150 m, but substantial levels of external pollen flow were also detected in Ibicatu (8%), although not in MGI (0.4%) or MGII (0%). Selfing was highest in MGII (18%), the smallest group of trees, compared to MGI (6.4%) and Ibicatu (6%). In MGI and MGII, there was a strong pattern of mating among near‐neighbors. Seed collection strategies for breeding, in situ and ex situ conservation and ecological restoration, must ensure collection from seed trees located at distances greater than 350 m and from several forest fragments.
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Affiliation(s)
- Evandro V Tambarussi
- Escola Superior de Agricultura "Luiz de Queiroz" Universidade de São Paulo Av. Pádua Dias, 11 Caixa Postal 9 Piracicaba 13418-900 Brazil
| | - David Boshier
- Department of Plant Sciences South Parks Road Oxford OX1 3RB UK
| | - Roland Vencovsky
- Escola Superior de Agricultura "Luiz de Queiroz" Universidade de São Paulo Av. Pádua Dias, 11 Caixa Postal 9 Piracicaba 13418-900 Brazil
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Rymer PD, Sandiford M, Harris SA, Billingham MR, Boshier DH. Remnant Pachira quinata pasture trees have greater opportunities to self and suffer reduced reproductive success due to inbreeding depression. Heredity (Edinb) 2015; 115:115-24. [PMID: 23963342 PMCID: PMC4815449 DOI: 10.1038/hdy.2013.73] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 04/24/2013] [Accepted: 05/08/2013] [Indexed: 11/08/2022] Open
Abstract
Habitat fragmentation is extensive throughout the world, converting natural ecosystems into fragments of varying size, density and connectivity. The potential value of remnant trees in agricultural landscapes as seed sources and in connecting fragments has formed a fertile area of debate. This study contrasted the mating patterns of bat-pollinated Pachira quinata trees in a continuous forest to those in pasture through microsatellite-based paternity analysis of progeny. The breeding system was determined by analysis of pollen tube growth and seed production from controlled pollinations. Fitness of selfed and outcrossed seed was compared by germination and seedling growth. There was more inbreeding within pasture trees (outcrossing=0.828±0.015) compared with forest trees (0.926±0.005). Pasture trees had fewer sires contributing to mating events, but pollen dispersal distances were greater than those in the forest. Paternity analysis showed variation in outcrossing rates among pasture trees with high proportions of external and self pollen sources detected. A leaky self-incompatibility system was found, with self pollen having reduced germination on stigmas and slower growth rate through the style. Controlled pollinations also showed a varied ability to self among trees, which was reflected in the selfing rates among pasture trees shown by the paternity analysis (0-80% selfing). Self pollination resulted in lower seed set, germination and seedling growth compared with outcrossing. While remnant trees in agricultural landscapes are involved in broader mating patterns, they show increased but varied levels of inbreeding, which result in reduced fitness.
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Affiliation(s)
- P D Rymer
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, UK
- Hawkesbury Institute for the Environment, University of Western Sydney, Bourke Street, Richmond, Australia
| | - M Sandiford
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, UK
| | - S A Harris
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, UK
| | - M R Billingham
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, UK
| | - D H Boshier
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, UK
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Breed MF, Ottewell KM, Gardner MG, Marklund MHK, Stead MG, Harris JBC, Lowe AJ. Mating system and early viability resistance to habitat fragmentation in a bird-pollinated eucalypt. Heredity (Edinb) 2015; 115:100-7. [PMID: 23188172 PMCID: PMC4815440 DOI: 10.1038/hdy.2012.72] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 06/06/2012] [Accepted: 06/29/2012] [Indexed: 11/09/2022] Open
Abstract
Habitat fragmentation has been shown to disrupt ecosystem processes such as plant-pollinator mutualisms. Consequently, mating patterns in remnant tree populations are expected to shift towards increased inbreeding and reduced pollen diversity, with fitness consequences for future generations. However, mating patterns and phenotypic assessments of open-pollinated progeny have rarely been combined in a single study. Here, we collected seeds from 37 Eucalyptus incrassata trees from contrasting stand densities following recent clearance in a single South Australian population (intact woodland=12.6 trees ha(-1); isolated pasture=1.7 trees ha(-1); population area=10 km(2)). 649 progeny from these trees were genotyped at eight microsatellite loci. We estimated genetic diversity, spatial genetic structure, indirect contemporary pollen flow and mating patterns for adults older than the clearance events and open-pollinated progeny sired post-clearance. A proxy of early stage progeny viability was assessed in a common garden experiment. Density had no impact on mating patterns, adult and progeny genetic diversity or progeny growth, but was associated with increased mean pollen dispersal. Weak spatial genetic structure among adults suggests high historical gene flow. We observed preliminary evidence for inbreeding depression related to stress caused by fungal infection, but which was not associated with density. Higher observed heterozygosities in adults compared with progeny may relate to weak selection on progeny and lifetime-accumulated mortality of inbred adults. E. incrassata appears to be resistant to the negative mating pattern and fitness changes expected within fragmented landscapes. This pattern is likely explained by strong outcrossing and regular long-distance pollen flow.
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Affiliation(s)
- M F Breed
- Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia
- Plant Ecology and Evolution, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen, Uppsala, Sweden
| | - K M Ottewell
- Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia
- Science Division, Department of Environment and Conservation, Perth, WA, Australia
| | - M G Gardner
- Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia
- School of Biological Sciences, Flinders University, Adelaide, SA, Australia
| | - M H K Marklund
- Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia
- Department of Limnology, Uppsala University, Evolutionary Biology Centre, Uppsala University, Norbyvägen, Uppsala, Sweden
| | - M G Stead
- Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia
| | - J B C Harris
- Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia
- Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ, USA
| | - A J Lowe
- Australian Centre for Evolutionary Biology and Biodiversity (ACEBB) and School of Earth and Environmental Sciences, University of Adelaide, North Terrace, SA, Australia
- State Herbarium of South Australia, Science Resource Centre, Department of Environment and Natural Resources, Hackney Road, Adelaide, SA, Australia
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Environmental requirements trump genetic factors in explaining narrow endemism in two imperiled Florida sunflowers. CONSERV GENET 2015. [DOI: 10.1007/s10592-015-0739-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Pellissier L. Stability and the competition-dispersal trade-off as drivers of speciation and biodiversity gradients. Front Ecol Evol 2015. [DOI: 10.3389/fevo.2015.00052] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Short-term genetic consequences of habitat loss and fragmentation for the neotropical palm Oenocarpus bataua. Heredity (Edinb) 2015; 115:389-95. [PMID: 25920669 DOI: 10.1038/hdy.2015.35] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 03/20/2015] [Accepted: 03/23/2015] [Indexed: 11/08/2022] Open
Abstract
Habitat loss and fragmentation may impact animal-mediated dispersal of seed and pollen, and a key question is how the genetic attributes of plant populations respond to these changes. Theory predicts that genetic diversity may be less sensitive to such disruptions in the short term, whereas inbreeding and genetic structure may respond more strongly. However, results from studies to date vary in relation to species, context and the parameter being assessed, triggering calls for more empirical studies, especially from the tropics, where plant-animal dispersal mutualisms are both disproportionately common and at risk. We compared the genetic characteristics of adults and recruits in a long-lived palm Oenocarpus bataua in a recently fragmented landscape (<2 generations) in northwest Ecuador using a suite of 10 polymorphic microsatellite markers. We sampled individuals from six forest fragments and one nearby continuous forest. Our goal was to assess short-term consequences of fragmentation, with a focus on how well empirical data from this system follow theoretical expectations. Mostly congruent with predictions, we found stronger genetic differentiation and fine-scale spatial genetic structure among recruits in fragments compared with recruits in continuous forest, but we did not record differences in genetic diversity or inbreeding, nor did we record any differences between adults in fragments and adults in continuous forest. Our findings suggest that genetic characteristics of populations vary in their sensitivity to change in response to habitat loss and fragmentation, and that fine-scale spatial genetic structure may be a particularly useful indicator of genetic change in recently fragmented landscapes.
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Contemporary and historic factors influence differently genetic differentiation and diversity in a tropical palm. Heredity (Edinb) 2015; 115:216-24. [PMID: 25873150 DOI: 10.1038/hdy.2015.30] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 03/03/2015] [Accepted: 03/12/2015] [Indexed: 11/08/2022] Open
Abstract
Population genetics theory predicts loss in genetic variability because of drift and inbreeding in isolated plant populations; however, it has been argued that long-distance pollination and seed dispersal may be able to maintain gene flow, even in highly fragmented landscapes. We tested how historical effective population size, historical migration and contemporary landscape structure, such as forest cover, patch isolation and matrix resistance, affect genetic variability and differentiation of seedlings in a tropical palm (Euterpe edulis) in a human-modified rainforest. We sampled 16 sites within five landscapes in the Brazilian Atlantic forest and assessed genetic variability and differentiation using eight microsatellite loci. Using a model selection approach, none of the covariates explained the variation observed in inbreeding coefficients among populations. The variation in genetic diversity among sites was best explained by historical effective population size. Allelic richness was best explained by historical effective population size and matrix resistance, whereas genetic differentiation was explained by matrix resistance. Coalescence analysis revealed high historical migration between sites within landscapes and constant historical population sizes, showing that the genetic differentiation is most likely due to recent changes caused by habitat loss and fragmentation. Overall, recent landscape changes have a greater influence on among-population genetic variation than historical gene flow process. As immediate restoration actions in landscapes with low forest amount, the development of more permeable matrices to allow the movement of pollinators and seed dispersers may be an effective strategy to maintain microevolutionary processes.
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Bertolasi B, Leonarduzzi C, Piotti A, Leonardi S, Zago L, Gui L, Gorian F, Vanetti I, Binelli G. A last stand in the Po valley: genetic structure and gene flow patterns in Ulmus minor and U. pumila. ANNALS OF BOTANY 2015; 115:683-92. [PMID: 25725008 PMCID: PMC4343291 DOI: 10.1093/aob/mcu256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Ulmus minor has been severely affected by Dutch elm disease (DED). The introduction into Europe of the exotic Ulmus pumila, highly tolerant to DED, has resulted in it widely replacing native U. minor populations. Morphological and genetic evidence of hybridization has been reported, and thus there is a need for assessment of interspecific gene flow patterns in natural populations. This work therefore aimed at studying pollen gene flow in a remnant U. minor stand surrounded by trees of both species scattered across an agricultural landscape. METHODS All trees from a small natural stand (350 in number) and the surrounding agricultural area within a 5-km radius (89) were genotyped at six microsatellite loci. Trees were morphologically characterized as U. minor, U. pumila or intermediate phenotypes, and morphological identification was compared with Bayesian clustering of genotypes. For paternity analysis, seeds were collected in two consecutive years from 20 and 28 mother trees. Maximum likelihood paternity assignment was used to elucidate intra- and interspecific gene flow patterns. KEY RESULTS Genetic structure analyses indicated the presence of two genetic clusters only partially matching the morphological identification. The paternity analysis results were consistent between the two consecutive years of sampling and showed high pollen immigration rates (∼0·80) and mean pollination distances (∼3 km), and a skewed distribution of reproductive success. Few intercluster pollinations and putative hybrid individuals were found. CONCLUSIONS Pollen gene flow is not impeded in the fragmented agricultural landscape investigated. High pollen immigration and extensive pollen dispersal distances are probably counteracting the potential loss of genetic variation caused by isolation. Some evidence was also found that U. minor and U. pumila can hybridize when in sympatry. Although hybridization might have beneficial effects on both species, remnant U. minor populations represent a valuable source of genetic diversity that needs to be preserved.
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Affiliation(s)
- B Bertolasi
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - C Leonarduzzi
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - A Piotti
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - S Leonardi
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - L Zago
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - L Gui
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - F Gorian
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - I Vanetti
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
| | - G Binelli
- Centro Nazionale per lo Studio e la Conservazione della Biodiversità Forestale, Corpo Forestale dello Stato, Via del Ponte 256, 37059 Peri (VR), Italy, Dipartimento di Bioscienze, Università di Parma, Viale Usberti 11/A, Parma, Italy, Institute of Biosciences and BioResources, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy and Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant 3, 21100 Varese (VA), Italy
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Dillon S, McEvoy R, Baldwin DS, Southerton S, Campbell C, Parsons Y, Rees GN. Genetic diversity ofEucalyptus camaldulensis Dehnh. following population decline in response to drought and altered hydrological regime. AUSTRAL ECOL 2015. [DOI: 10.1111/aec.12223] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Shannon Dillon
- CSIRO Agriculture Flagship; Acton Australian Capital Territory 2600 Australia
| | - Rachel McEvoy
- Department of Genetics; La Trobe University; Bundoora Victoria Australia
| | - Darren S. Baldwin
- Murray-Darling Freshwater Research Centre; Wodonga Victoria Australia
- CSIRO Land and Water Flagship; Wodonga Victoria Australia
| | - Simon Southerton
- CSIRO Agriculture Flagship; Acton Australian Capital Territory 2600 Australia
| | - Cherie Campbell
- Murray-Darling Freshwater Research Centre; Wodonga Victoria Australia
- CSIRO Land and Water Flagship; Wodonga Victoria Australia
| | - Yvonne Parsons
- Department of Genetics; La Trobe University; Bundoora Victoria Australia
| | - Gavin N. Rees
- Murray-Darling Freshwater Research Centre; Wodonga Victoria Australia
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45
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Kikuchi S, Shibata M, Tanaka H. Effects of forest fragmentation on the mating system of a cool-temperate heterodichogamous tree Acer mono. Glob Ecol Conserv 2015. [DOI: 10.1016/j.gecco.2015.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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46
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Finger A, Kaiser-Bunbury CN, Kettle CJ, Valentin T, Ghazoul J. Genetic connectivity of the moth pollinated tree Glionnetia sericea in a highly fragmented habitat. PLoS One 2014; 9:e111111. [PMID: 25347541 PMCID: PMC4210268 DOI: 10.1371/journal.pone.0111111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 09/23/2014] [Indexed: 11/20/2022] Open
Abstract
Long-distance gene flow is thought to be one prerequisite for the persistence of plant species in fragmented environments. Human influences have led to severe fragmentation of native habitats in the Seychelles islands, with many species surviving only in small and isolated populations. The endangered Seychelles endemic tree Glionnetia sericea is restricted to altitudes between 450 m and 900 m where the native forest vegetation has been largely lost and replaced with exotic invasives over the last 200 years. This study explores the genetic and ecological consequences of population fragmentation in this species by analysing patterns of genetic diversity in a sample of adults, juveniles and seeds, and by using controlled pollination experiments. Our results show no decrease in genetic diversity and no increase in genetic structuring from adult to juvenile cohorts. Despite significant inbreeding in some populations, there is no evidence of higher inbreeding in juvenile cohorts relative to adults. A Bayesian structure analysis and a tentative paternity analysis indicate extensive historical and contemporary gene flow among remnant populations. Pollination experiments and a paternity analysis show that Glionnetia sericea is self-compatible. Nevertheless, outcrossing is present with 7% of mating events resulting from pollen transfer between populations. Artificial pollination provided no evidence for pollen limitation in isolated populations. The highly mobile and specialized hawkmoth pollinators (Agrius convolvuli and Cenophodes tamsi; Sphingidae) appear to promote extensive gene flow, thus mitigating the potential negative ecological and genetic effects of habitat fragmentation in this species. We conclude that contemporary gene flow is sufficient to maintain genetic connectivity in this rare and restricted Seychelles endemic, in contrast to other island endemic tree species with limited contemporary gene flow.
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Affiliation(s)
- Aline Finger
- Environmental Systems Science, ETH Zürich, Zürich, Switzerland
- * E-mail:
| | | | - Chris J. Kettle
- Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | | | - Jaboury Ghazoul
- Environmental Systems Science, ETH Zürich, Zürich, Switzerland
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47
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Gaoue OG, Lemes MR, Ticktin T, Sinsin B, Eyog-Matig O. Non-timber Forest Product Harvest does not Affect the Genetic Diversity of a Tropical Tree Despite Negative Effects on Population Fitness. Biotropica 2014. [DOI: 10.1111/btp.12145] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Orou G. Gaoue
- Department of Botany; University of Hawaii at Manoa; Honolulu HI 96822 U.S.A
- Laboratoire d'Ecologie Appliquée; Université d'Abomey Calavi; Cotonou Benin
| | - Maristerra R. Lemes
- Laboratório de Genética e Biologia Reprodutiva de Plantas; Instituto Nacional de Pesquisas da Amazônia; Manaus-AM Brazil
- Instituto de Pesquisas Jardim Botânico do Rio de Janeiro; Jardim Botânico; Rio de Janeiro RJ Brazil
| | - Tamara Ticktin
- Department of Botany; University of Hawaii at Manoa; Honolulu HI 96822 U.S.A
| | - Brice Sinsin
- Laboratoire d'Ecologie Appliquée; Université d'Abomey Calavi; Cotonou Benin
| | - Oscar Eyog-Matig
- Bioversity International; c/o CIFOR Regional Office; Yaounde Cameroon
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48
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Effects of Population Size, Forest Fragmentation, and Urbanization on Seed Production and Gene Flow in an Endangered Maple (Acer miyabei). AMERICAN MIDLAND NATURALIST 2014. [DOI: 10.1674/0003-0031-172.2.303] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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49
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Millar MA, Coates DJ, Byrne M. Extensive long-distance pollen dispersal and highly outcrossed mating in historically small and disjunct populations of Acacia woodmaniorum (Fabaceae), a rare banded iron formation endemic. ANNALS OF BOTANY 2014; 114:961-971. [PMID: 25100675 PMCID: PMC4171076 DOI: 10.1093/aob/mcu167] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 06/30/2014] [Indexed: 05/30/2023]
Abstract
BACKGROUND AND AIMS Understanding patterns of pollen dispersal and variation in mating systems provides insights into the evolutionary potential of plant species and how historically rare species with small disjunct populations persist over long time frames. This study aims to quantify the role of pollen dispersal and the mating system in maintaining contemporary levels of connectivity and facilitating persistence of small populations of the historically rare Acacia woodmaniorum. METHODS Progeny arrays of A. woodmaniorum were genotyped with nine polymorphic microsatellite markers. A low number of fathers contributed to seed within single pods; therefore, sampling to remove bias of correlated paternity was implemented for further analysis. Pollen immigration and mating system parameters were then assessed in eight populations of varying size and degree of isolation. KEY RESULTS Pollen immigration into small disjunct populations was extensive (mean minimum estimate 40 % and mean maximum estimate 57 % of progeny) and dispersal occurred over large distances (≤1870m). Pollen immigration resulted in large effective population sizes and was sufficient to ensure adaptive and inbreeding connectivity in small disjunct populations. High outcrossing (mean tm = 0·975) and a lack of apparent inbreeding suggested that a self-incompatibility mechanism is operating. Population parameters, including size and degree of geographic disjunction, were not useful predictors of pollen dispersal or components of the mating system. CONCLUSIONS Extensive long-distance pollen dispersal and a highly outcrossed mating system are likely to play a key role in maintaining genetic diversity and limiting negative genetic effects of inbreeding and drift in small disjunct populations of A. woodmaniorum. It is proposed that maintenance of genetic connectivity through habitat and pollinator conservation will be a key factor in the persistence of this and other historically rare species with similar extensive long-distance pollen dispersal and highly outcrossed mating systems.
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Affiliation(s)
- Melissa A Millar
- Science and Conservation Division, Department of Parks and Wildlife, Locked Bag 104, Bentley Delivery Centre, Bentley, WA 6983, Australia
| | - David J Coates
- Science and Conservation Division, Department of Parks and Wildlife, Locked Bag 104, Bentley Delivery Centre, Bentley, WA 6983, Australia
| | - Margaret Byrne
- Science and Conservation Division, Department of Parks and Wildlife, Locked Bag 104, Bentley Delivery Centre, Bentley, WA 6983, Australia
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50
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Ellstrand NC. Is gene flow the most important evolutionary force in plants? AMERICAN JOURNAL OF BOTANY 2014; 101:737-53. [PMID: 24752890 DOI: 10.3732/ajb.1400024] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 03/17/2014] [Indexed: 05/02/2023]
Abstract
Although theory has demonstrated rather low levels of gene flow are sufficient to counteract opposing mutation, drift, and selection, widespread recognition of the evolutionary importance of gene flow has come slowly. The perceived role of gene flow as an evolutionary force has vacillated over the last century. In the last few decades, new methods and analyses have demonstrated that plant gene flow rates vary tremendously-from nil to very high-depending on the species and specific populations involved, and sometimes over time for individual populations. In many cases, the measured gene flow rates are evolutionarily significant at distances of hundreds and sometimes thousands of meters, occurring at levels sufficient to counteract drift, spread advantageous alleles, or thwart moderate levels of opposing local selection. Gene flow in plants is likely to often act as a cohesive force, uniting individual plant species into real evolutionary units. Also, gene flow can evolve under natural selection, decreasing or increasing. The fact of frequent, but variable, plant gene flow has important consequences for applied issues in which the presence or absence of gene flow might influence the outcome of a policy, regulatory, or management decision. Examples include the unintended spread of engineered genes, the evolution of invasiveness, and conservation. New data-rich genomic techniques allow closer scrutiny of the role of gene flow in plant evolution. Most plant evolutionists now recognize the importance of gene flow, and it is receiving increased recognition from other areas of plant biology as well.
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Affiliation(s)
- Norman C Ellstrand
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521-0124 USA
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