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Hou M, Opedal ØH, Zhao ZG. Sexually concordant selection on floral traits despite greater opportunity for selection through male fitness. THE NEW PHYTOLOGIST 2024; 241:926-936. [PMID: 37899633 DOI: 10.1111/nph.19370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 10/16/2023] [Indexed: 10/31/2023]
Abstract
Pollinators are important drivers of floral trait evolution, yet plant populations are not always perfectly adapted to their pollinators. Such apparent maladaptation may result from conflicting selection through male and female sexual functions in hermaphrodites. We studied sex-specific mating patterns and phenotypic selection on floral traits in Aconitum gymnandrum. After genotyping 1786 offspring, we partitioned individual fitness into sex-specific selfed and outcrossed components and estimated phenotypic selection acting through each. Relative fitness increased with increasing mate number, and more so for male function. This led to greater opportunity for selection through outcrossed male fitness, though patterns of phenotypic selection on floral traits tended to be similar, and with better support for selection through female rather than male fitness components. We detected directional selection through one or more fitness component for larger flower number, larger flowers, and more negative nectar gradients within inflorescences. Our results are consistent with Bateman's principles for sex-specific mating patterns and illustrate that, despite the expected difference in opportunity for selection, patterns of variation in selection across traits can be rather similar for the male and female sexual functions. These results shed new light on the effect of sexual selection on the evolution of floral traits.
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Affiliation(s)
- Meng Hou
- College of Ecology, Lanzhou University, 730000, Lanzhou, China
- Key Laboratory of Wetland Ecology and Environment, State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 130102, Changchun, China
| | | | - Zhi-Gang Zhao
- College of Ecology, Lanzhou University, 730000, Lanzhou, China
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Zhou ZL, Wang GY, Wang XL, Huang XJ, Zhu ZS, Wang LL, Yang YP, Duan YW. Flower color polymorphism of a wild Iris on the Qinghai-Tibet plateau. BMC PLANT BIOLOGY 2023; 23:633. [PMID: 38066415 PMCID: PMC10709947 DOI: 10.1186/s12870-023-04642-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023]
Abstract
BACKGROUND Flower color plays a crucial role in attracting pollinators and facilitating environmental adaptation. Investigating the causes of flower color polymorphism and understanding their potential effects on both ecology and genetics can enhance our understanding of flower color polymorphism in wild plant. RESULTS In this study, we examined the differences of potential male and female fitness between purple- and yellow- flower individuals in Iris potaninii on the Qinghai-Tibet Plateau, and screened key genes and positively selective genes involved in flower color change. Our results showed that yellow flower exhibited a higher pollen-to-ovule ratio. Yellow flowers were derived from purple flowers due to the loss of anthocyanins, and F3H could be an essential gene affecting flower color variation though expression regulation and sequence polymorphism in this species. Furthermore, our findings suggest that genes positively selected in yellow-flowered I. potaninii might be involved in nucleotide excision repair and plant-pathogen interactions. CONCLUSIONS These results suggest that F3H induces the flower color variation of Iris potaninii, and the subsequent ecological and additive positive selection on yellow flowers may further enhance plant adaptations to alpine environments.
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Affiliation(s)
- Zhi-Li Zhou
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Guang-Yan Wang
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Xi-Long Wang
- Tibet Plateau Institute of Biology, Lhasa, Xizang, 850001, China
| | - Xiao-Juan Huang
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Zhang-Shichang Zhu
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Lin-Lin Wang
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Yong-Ping Yang
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China.
| | - Yuan-Wen Duan
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China.
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Haghighatnia M, Machac A, Schmickl R, Lafon Placette C. Darwin's 'mystery of mysteries': the role of sexual selection in plant speciation. Biol Rev Camb Philos Soc 2023; 98:1928-1944. [PMID: 37337476 DOI: 10.1111/brv.12991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 06/02/2023] [Accepted: 06/07/2023] [Indexed: 06/21/2023]
Abstract
Sexual selection is considered one of the key processes that contribute to the emergence of new species. While the connection between sexual selection and speciation has been supported by comparative studies, the mechanisms that mediate this connection remain unresolved, especially in plants. Similarly, it is not clear how speciation processes within plant populations translate into large-scale speciation dynamics. Here, we review the mechanisms through which sexual selection, pollination, and mate choice unfold and interact, and how they may ultimately produce reproductive isolation in plants. We also overview reproductive strategies that might influence sexual selection in plants and illustrate how functional traits might connect speciation at the population level (population differentiation, evolution of reproductive barriers; i.e. microevolution) with evolution above the species level (macroevolution). We also identify outstanding questions in the field, and suitable data and tools for their resolution. Altogether, this effort motivates further research focused on plants, which might potentially broaden our general understanding of speciation by sexual selection, a major concept in evolutionary biology.
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Affiliation(s)
- Mohammadjavad Haghighatnia
- Department of Botany, Faculty of Science, Charles University, Benatska 2, Prague, CZ-128 01, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
| | - Antonin Machac
- Laboratory of Environmental Microbiology, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, Prague, 14220, Czech Republic
| | - Roswitha Schmickl
- Department of Botany, Faculty of Science, Charles University, Benatska 2, Prague, CZ-128 01, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
| | - Clément Lafon Placette
- Department of Botany, Faculty of Science, Charles University, Benatska 2, Prague, CZ-128 01, Czech Republic
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Nepal S, Trunschke J, Ren ZX, Burgess KS, Wang H. Community-wide patterns in pollen and ovule production, their ratio (P/O), and other floral traits along an elevation gradient in southwestern China. BMC PLANT BIOLOGY 2023; 23:425. [PMID: 37710175 PMCID: PMC10500814 DOI: 10.1186/s12870-023-04433-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/31/2023] [Indexed: 09/16/2023]
Abstract
BACKGROUND As the male and female gametophytes of flowering plants, pollen and ovules largely determine the upper and lower boundaries of plant reproductive success. It is commonly predicted that pollen and ovule number per flower should increase, and pollen-ovule ratio (P/O) per flower should decrease with increasing elevation in response to a more stochastic pollination environment. Here, we aimed to determine the response of pollen number, ovule number, and P/O to other floral traits and elevation gradients for 84 insect-pollinated herbaceous flowering plant species in five sub-alpine and alpine communities (2709 to 3896 m a.s.l.) on Yulong Snow Mountain, southwestern China. RESULTS Six floral traits, including P/O, floral display area, flower number, tube depth, flower shape, and pollen presentation, were highly correlated with pollen and ovule number per flower. With increasing elevation, pollen number and P/O per flower increased marginally and significantly, respectively; ovule number per individual, flower number per individual, stigma stamen separation, and inflorescence height decreased significantly. However, ovule number per flower and other floral traits (i.e., floral display area, tube depth, stigma height, stamen height, and pollen and P/O per individual) did not change with elevation. We detected significant phylogenetic signals for pollen number, ovule number, and P/O, suggesting that these traits may be highly conserved and with limited response to changing environmental conditions. CONCLUSIONS Results revealed patterns of plant reproductive character evolution along elevation gradients and the potential factors governing their spatial variation in high-elevation environments. Plant species at high elevations are more likely adapted to cross-pollination, indicated by increased P/O per flower at high elevations on Yulong Mountain. Combined effects of phylogenetic history and plant-pollinator interactions should determine plant trait evolution.
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Affiliation(s)
- Shristhi Nepal
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Judith Trunschke
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Nature Conservation and Landscape Ecology, Faculty of Environment and Natural Resources, University of Freiburg, Freiburg, Germany
| | - Zong-Xin Ren
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Kevin S Burgess
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.
- Department of Biology, College of Letters and Sciences, Columbus State University, University System of Georgia, Columbus, GA, 31907-5645, USA.
| | - Hong Wang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.
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Štenc J, Janošík L, Matoušková E, Hadrava J, Mikát M, Janovský Z. Pollinator visitation closely tracks diurnal patterns in pollen release. AMERICAN JOURNAL OF BOTANY 2023:e16179. [PMID: 37200483 DOI: 10.1002/ajb2.16179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 05/20/2023]
Abstract
PREMISE Animal-pollinated plants face a high risk of pollen loss during its transfer. To limit the negative effect of pollen losses by pollen consumption and heterospecific transfer, plant species may adjust and stratify their pollen availability during the day (i.e., "schedule" their pollen presentation) and attract pollinators in specific time frames. METHODS We investigated diurnal patterns of pollen availability and pollinator visitation in three coflowering plant species: Succisa pratensis with open flowers and accessible pollen, pollinated mainly by pollen-feeding hoverflies; Centaurea jacea with open flowers and less accessible pollen, pollinated mainly by pollen-collecting bees; and Trifolium hybridum with closed flowers and pollen accessible only after the active opening of the flower, pollinated exclusively by bees. RESULTS The three plant species differed in the peak pollen availability, tracked by the visitation activity of their pollinators. Succisa pratensis released all pollen in the morning, while pollinator activity was still low and peaked with a slight delay. In contrast, C. jacea and T. hybridum had distinct pollen presentation schedules, peaking in the early afternoon. The pollinator visitation to both of these species closely matched their pollen availability. CONCLUSIONS Stratifying pollen availability to pollinators during the day may be one of several mechanisms that allow coflowering plants to share their pollinators and decrease the probability of heterospecific pollen transfer.
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Affiliation(s)
- Jakub Štenc
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 41, Prague, Czech Republic
| | - Lukáš Janošík
- Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-128 41, Prague, Czech Republic
| | - Eva Matoušková
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ-128 41, Prague, Czech Republic
| | - Jiří Hadrava
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ-128 41, Prague, Czech Republic
| | - Michael Mikát
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ-128 41, Prague, Czech Republic
- Department of Biology, Faculty of Science, York University, 4700 Keele Street, 203D, M3J 1P3, Toronto, Canada
- Department of General Zoology, Faculty of Natural Sciences 1-Biosciences, Martin Luther University, Hoher Weg 8, 06100 Halle (Saale), Germany
| | - Zdeněk Janovský
- Svatý Jan t. Krsovice 1, 285 04 Uhlířské Janovice, Czech Republic
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Hao K, Xu Q, Huang SQ. Pollen-feeding behavior of diverse insects on Geranium delavayi, a flower with large, accessible pollen grains. AMERICAN JOURNAL OF BOTANY 2023; 110:e16113. [PMID: 36462154 DOI: 10.1002/ajb2.16113] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
PREMISE Why have pollen grains evolved to be exceptionally large in some species? Pollen-feeding hypothesis suggests that if the proportion of pollen amounts for feeding is reduced in a flower, the low allocation to pollen number would allow pollen grains to be larger. METHODS To examine whether species with large pollen grains experience low pollen consumption, the behavior of insects feeding on nectar and pollen was observed and pollen transfer efficiency was estimated for four visitor types in Geranium delavayi. To see whether bees actively collected pollen, the numbers of grains in pollen baskets and on the body were compared. Both nutritional value (total protein and lipid) and chemical defense (phenolic metabolites) in pollen against pollen feeders were measured. RESULTS Bumblebees and honeybees foraged for nectar, rarely groomed pollen into corbiculae, and had >5× higher pollen transfer efficiency than smaller solitary bees and flies, which were pollen eaters that removed more pollen but deposited less. Pollen grains were characterized by low protein and high lipid content with a low protein-lipid ratio, an unfavorable combination for bumblebees. Three secondary metabolites were significantly higher in pollen grains (7.77 mg/g) than in petals (1.08 mg/g) or in nectar (0.44 mg/g), suggesting stronger chemical defense in pollen. CONCLUSIONS Our results indicated that large bees took nectar but little of the nutritionally poor and highly toxic pollen. These data support one prediction of the pollen-feeding hypothesis, that species with few and large pollen grains would also have low pollen-consumption rates.
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Affiliation(s)
- Kai Hao
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Qi Xu
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Shuang-Quan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
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Pontes CADS, Domingos-Melo A, Milet-Pinheiro P, Navarro DMDAF, Lima Nadia T, Machado IC. Staminode of Jacaranda rugosa A.H. Gentry (Bignoniaceae) promotes functional specialization by ensuring signaling and mechanical fit to medium-sized bees. ORG DIVERS EVOL 2022. [DOI: 10.1007/s13127-022-00558-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Range expansion decreases the reproductive fitness of Gentiana officinalis (Gentianaceae). Sci Rep 2022; 12:2461. [PMID: 35165323 PMCID: PMC8844042 DOI: 10.1038/s41598-022-06406-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 01/19/2022] [Indexed: 11/23/2022] Open
Abstract
Plants living at the edge of their range boundary tend to suffer an overall decline in their fitness, including growth and reproduction. However, the reproductive performance of plants in artificially expanded habitats is rarely investigated, although this type of study would provide a better understanding of range limitations and improved conservation of ex situ plants. In the current study, we transplanted a narrowly dispersed species of Gentiana officinalis H. Smith (Gentianaceae) from its natural area of distribution to two different elevations and natural elevation to comprehensively study its pollination biology, including flowering phenology and duration, floral display, reproductive allocation, pollinator activity, and seed production. The findings indicated that the starting point and endpoint of the flowering phenology of G. officinalis were earlier at the low elevation, but the peak flowering periods did not differ significantly between any of the experimental plots. When transplanted, the flowering duration, especially the female phase, was reduced; the floral display, including spray numbers, flower numbers, and flower size (length and width), decreased, especially at high elevations. Moreover, the pollen numbers and pollen-ovule ratio were decreased at both high and low elevations, although the ovule numbers showed no change, and aboveground reproductive allocation was decreased. Furthermore, pollinator richness and activity were significantly decreased, and the seed-set ratio decreased under both natural conditions and with supplemental pollination. Finally, more severe pollen limitation was found in transplanted individuals. These results indicated an overall decrease in reproductive fitness in plants living outside their original area of distribution when the geographical range of G. officinalis was expanded.
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A New Approach to Inform Restoration and Management Decisions for Sustainable Apiculture. SUSTAINABILITY 2021. [DOI: 10.3390/su13116109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Habitat loss has reduced the available resources for apiarists and is a key driver of poor colony health, colony loss, and reduced honey yields. The biggest challenge for apiarists in the future will be meeting increasing demands for pollination services, honey, and other bee products with limited resources. Targeted landscape restoration focusing on high-value or high-yielding forage could ensure adequate floral resources are available to sustain the growing industry. Tools are currently needed to evaluate the likely productivity of potential sites for restoration and inform decisions about plant selections and arrangements and hive stocking rates, movements, and placements. We propose a new approach for designing sites for apiculture, centred on a model of honey production that predicts how changes to plant and hive decisions affect the resource supply, potential for bees to collect resources, consumption of resources by the colonies, and subsequently, amount of honey that may be produced. The proposed model is discussed with reference to existing models, and data input requirements are discussed with reference to an Australian case study area. We conclude that no existing model exactly meets the requirements of our proposed approach, but components of several existing models could be combined to achieve these needs.
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Hao K, Tian ZX, Wang ZC, Huang SQ. Pollen grain size associated with pollinator feeding strategy. Proc Biol Sci 2020; 287:20201191. [PMID: 32811305 PMCID: PMC7482274 DOI: 10.1098/rspb.2020.1191] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 07/24/2020] [Indexed: 02/06/2023] Open
Abstract
Angiosperm pollen grain diameter varies greatly from a few microns to over 100, but the selective forces driving the interspecific variation in pollen size remain unclear. Although both pre- and post-pollination hypotheses have been proposed, empirical evidence remains scarce. Here we propose that visits by pollen-foraging pollinators have selected against large pollen grains. An association between pollinator behaviour and pollen grain size was confirmed by field studies of 80 flowering species in natural communities, showing that pollinators positively collected pollen in those species with relatively smaller pollen grains but rarely did so in species with larger ones. Allowing for the confounding effects of pollinator type, flower size or style length and pollen grain number, we found a significant effect of pollen-foraging behaviour on variation in pollen grain size, particularly in bee-pollinated plants. While these results suggest that many plant species whose pollen is collected or consumed by pollinators produce small pollen grains, it remains unclear whether pollen grain size is directly affected by pollinator foraging habit or indirectly mediated by pollen number trade-offs.
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Affiliation(s)
| | | | | | - Shuang-Quan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan 430079, People's Republic of China
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Pellmyr O, Kjellberg F, Herre EA, Kawakita A, Hembry DH, Holland JN, Terrazas T, Clement W, Segraves KA, Althoff DM. Active pollination drives selection for reduced pollen-ovule ratios. AMERICAN JOURNAL OF BOTANY 2020; 107:164-170. [PMID: 31889299 DOI: 10.1002/ajb2.1412] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
PREMISE Variation in pollen-ovule ratios is thought to reflect the degree of pollen transfer efficiency-the more efficient the process, the fewer pollen grains needed. Few studies have directly examined the relationship between pollen-ovule ratio and pollen transfer efficiency. For active pollination in the pollination brood mutualisms of yuccas and yucca moths, figs and fig wasps, senita and senita moths, and leafflowers and leafflower moths, pollinators purposefully collect pollen and place it directly on the stigmatic surface of conspecific flowers. The tight coupling of insect reproductive interests with pollination of the flowers in which larvae develop ensures that pollination is highly efficient. METHODS We used the multiple evolutionary transitions between passive pollination and more efficient active pollination to test if increased pollen transfer efficiency leads to reduced pollen-ovule ratios. We collected pollen and ovule data from a suite of plant species from each of the pollination brood mutualisms and used phylogenetically controlled tests and sister-group comparisons to examine whether the shift to active pollination resulted in reduced pollen-ovule ratios. RESULTS Across all transitions between passive and active pollination in plants, actively pollinated plants had significantly lower pollen-ovule ratios than closely related passively pollinated taxa. Phylogenetically corrected comparisons demonstrated that actively pollinated plant species had an average 76% reduction in the pollen-ovule ratio. CONCLUSIONS The results for active pollination systems support the general utility of pollen-ovule ratios as indicators of pollination efficiency and the central importance of pollen transfer efficiency in the evolution of pollen-ovule ratio.
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Affiliation(s)
- Olle Pellmyr
- Department of Biology, University of Idaho, Moscow, Idaho, 83844, USA
| | - Finn Kjellberg
- CEFE, CNRS, Université Montpellier, Université Paul Valéry Montpellier, EPHE, IRD, Montpellier, Cédex 5, France
| | - Edward Allen Herre
- Smithsonian Tropical Research Institute, Apartado Postal, 0843-03092, Panamá, Republic of Panama
| | - Atsushi Kawakita
- The Botanical Gardens, Graduate School of Science, University of Tokyo, 3-7-1 Hakusan, Bonkyo-ku, Tokyo, Japan
| | - David H Hembry
- Department of Entomology, Cornell University, 2130 Comstock Hall, Ithaca, New York, 14853, USA
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721, USA
| | - J Nathaniel Holland
- School of Dentistry, University of Texas, 7500 Cambridge Street, Houston, Texas, 77054, USA
| | - Teresa Terrazas
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
| | - Wendy Clement
- Department of Biology, The College of New Jersey, 2000 Pennington Road, Ewing, New Jersey, 08628, USA
| | - Kari A Segraves
- Department of Biology, Syracuse University, 107 College Place, Syracuse, New York, 13244, USA
| | - David M Althoff
- Department of Biology, Syracuse University, 107 College Place, Syracuse, New York, 13244, USA
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Page ML, Ison JL, Bewley AL, Holsinger KM, Kaul AD, Koch KE, Kolis KM, Wagenius S. Pollinator effectiveness in a composite: a specialist bee pollinates more florets but does not move pollen farther than other visitors. AMERICAN JOURNAL OF BOTANY 2019; 106:1487-1498. [PMID: 31713237 DOI: 10.1002/ajb2.1383] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/23/2019] [Indexed: 06/10/2023]
Abstract
PREMISE Variation in pollinator effectiveness may contribute to pollen limitation in fragmented plant populations. In plants with multiovulate ovaries, the number of conspecific pollen grains per stigma often predicts seed set and is used to quantify pollinator effectiveness. In the Asteraceae, however, florets are uniovulate, which suggests that the total amount of pollen deposited per floret may not measure pollinator effectiveness. We examined two aspects of pollinator effectiveness-effective pollen deposition and effective pollen movement-for insects visiting Echinacea angustifolia, a composite that is pollen limited in small, isolated populations. METHODS We filmed insect visits to Echinacea in two prairie restorations and used these videos to quantify behavior that might predict effectiveness. To quantify effective pollen deposition, we used the number of styles shriveled per visit. To quantify effective pollen movement, we conducted paternity analysis on a subset of offspring and measured the pollen movement distance between mates. RESULTS Effective pollen deposition varied among taxa. Andrena helianthiformis, a Heliantheae oligolege, was the most effective taxon, shriveling more than twice the proportion of styles as all other visitors. Differences in visitor behavior on a flowering head did not explain variation in effective pollen deposition, nor did flowering phenology. On average, visitors moved pollen 16 m between plants, and this distance did not vary among taxa. CONCLUSIONS Andrena helianthiformis is an important pollinator of Echinacea. Variation in reproductive fitness of Echinacea in fragmented habitat may result, in part, from the abundance of this species.
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Affiliation(s)
- Maureen L Page
- Department of Entomology and Nematology, University of California-Davis, One Shields Avenue, Davis, California, 95616, USA
- Biology Department, Scripps College, 1030 Columbia Avenue, Claremont, California, 91711, USA
| | - Jennifer L Ison
- Biology Department, College of Wooster, 1189 Beall Avenue, Wooster, Ohio, 44691, USA
| | - Alison L Bewley
- Biology Department, Wittenberg University, 200 W. Ward Street, Springfield, Ohio, 45504, USA
| | - Keaton M Holsinger
- Biology Department, Wabash College, 301 West Wabash Avenue, Crawfordsville, Indiana, 47933, USA
| | - Andrew D Kaul
- Biology Department, St. Olaf College, 1520 St. Olaf Avenue, Northfield, Minnesota, 55057, USA
| | - Katie E Koch
- Biology Department, Lakeland University, W3718 South Drive, Plymouth, Wisconsin, 53073, USA
| | - Kory M Kolis
- Biology Department, Gustavus Adolphus College, 800 West College Avenue, Saint Peter, Minnesota, 56082, USA
| | - Stuart Wagenius
- Division of Plant Biology and Conservation, Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, Illinois, 60022, USA
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Xiong YZ, Jia LB, Zhang C, Huang SQ. Color-matching between pollen and corolla: hiding pollen via visual crypsis? THE NEW PHYTOLOGIST 2019; 224:1142-1150. [PMID: 31225909 DOI: 10.1111/nph.16012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/14/2019] [Indexed: 06/09/2023]
Abstract
Visual signals attractive to friends may also attract enemies. The bright colors of anthers and pollen have generally been thought to attract pollinators. We hypothesize that visual crypsis of anthers, and particularly pollen, should be favored in flowering plants because protection from pollen collectors reduces the loss of male gametes. To understand adaptive strategies relating to the color of pollen, we measured the color of pollen, undehisced anther sacs, and their background, the corolla, with a spectrometer for 104 insect-pollinated flowering species from a natural community in Hengduan Mountains, southwest China. The colors of anthers, pollen and corollas were diverse in these species. The color diversity of exposed pollen was significantly higher than that of concealed pollen (i.e. where anthers are enclosed or shielded by corollas). The color contrast between pollen and corolla was significantly smaller in species with exposed pollen than in those with concealed pollen. Unlike anther color, exposed pollen color tended to match its background corolla color. Our phylogenetic comparative analysis showed contrasting effects of pollen color patterns between flowers with exposed pollen and those with concealed pollen, revealing a strategy of hiding pollen from pollen thieves via visual crypsis.
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Affiliation(s)
- Ying-Ze Xiong
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, New England Biolabs, 430079, China
| | - Li-Bing Jia
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, New England Biolabs, 430079, China
| | - Chuan Zhang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, New England Biolabs, 430079, China
| | - Shuang-Quan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, New England Biolabs, 430079, China
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Minnaar C, Anderson B. Using quantum dots as pollen labels to track the fates of individual pollen grains. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13155] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Corneile Minnaar
- Department of Botany and Zoology; Stellenbosch University; Matieland South Africa
| | - Bruce Anderson
- Department of Botany and Zoology; Stellenbosch University; Matieland South Africa
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15
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Minnaar C, Anderson B, de Jager ML, Karron JD. Plant-pollinator interactions along the pathway to paternity. ANNALS OF BOTANY 2019; 123:225-245. [PMID: 30535041 PMCID: PMC6344347 DOI: 10.1093/aob/mcy167] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 11/23/2018] [Indexed: 05/09/2023]
Abstract
Background The male fitness pathway, from pollen production to ovule fertilization, is thought to strongly influence reproductive trait evolution in animal-pollinated plants. This pathway is characterized by multiple avenues of pollen loss which may lead to reductions in male fitness. However, empirical data on the mechanistic processes leading to pollen loss during transport are limited, and we therefore lack a comprehensive understanding of how male fitness is influenced by each step in the pollination process. Scope This review assesses the history of studying male function in plants and identifies critical gaps in our understanding of the ecology and evolution of pollen transport. We explore male reproductive function along the steps of the pathway to paternity and discuss evolutionary options to overcome barriers to siring success. In particular, we present a newly emerging idea that bodies of pollinators function as a dynamic arena facilitating intense male-male competition, where pollen of rival males is constantly covered or displaced by competitors. This perspective extends the pollen-competitive arena beyond the confines of the stigma and style, and highlights the opportunity for important new breakthroughs in the study of male reproductive strategies and floral evolution.
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Affiliation(s)
- Corneile Minnaar
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Bruce Anderson
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Marinus L de Jager
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
| | - Jeffrey D Karron
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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Liu Y, Neal Stewart C, Li J, Wei W. One species to another: sympatric Bt transgene gene flow from Brassica napus alters the reproductive strategy of wild relative Brassica juncea under herbivore treatment. ANNALS OF BOTANY 2018; 122:617-625. [PMID: 29878055 PMCID: PMC6153478 DOI: 10.1093/aob/mcy096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 05/10/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND AND AIMS Since pollen flow or seed dispersal can contribute to transgene persistence in the environment, the sympatric presence of transgenic crops with their wild relatives is an ecological concern. In this study, we tested the hypothesis that proximate growth of a herbivore-resistant Bt crop and wild relatives coupled with the presence of herbivores can increase relative frequency of crop-to-wild transgene flow persistence outside of cultivation. METHODS We conducted a field experiment using insect enclosures with and without herbivores with cultivated Bt-transgenic Brassica napus (Bt OSR) and wild brown mustard (Brassica juncea) in pure and mixed stands. Low-density diamondback moth (Plutella xylostella) caterpillar infestation treatments were applied and transgene flow and reproductive organs were measured. KEY RESULTS Bt-transgenic B. napus produced more ovules and pollen than wild mustard, but the pollen to ovule (P/O) ratio in the two species was not significantly different. Low-level herbivory had no effects on fitness parameters of Bt OSR or wild brown mustard or on the transgene flow frequency. All progeny from wild brown mustard containing the Bt transgene came from mixed stands, with a gene flow frequency of 0.66 %. In mixed stands, wild brown mustard produced less pollen and more ovules than in pure stands of brown mustard. This indicates a decreased P/O ratio in a mixed population scenario. CONCLUSIONS Since a lower P/O ratio indicates a shift in sex allocation towards relatively greater female investment and a higher pollen transfer efficiency, the presence of transgenic plants in wild populations may further increase the potential transgene flow by altering reproductive allocation of wild species.
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Affiliation(s)
- Yongbo Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
| | - Junsheng Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Wei Wei
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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17
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Wang XY, Quan QM, Wang B, Li YX, Huang SQ. Pollen competition between morphs in a pollen-color dimorphic herb and the loss of phenotypic polymorphism within populations. Evolution 2018; 72:785-797. [PMID: 29399790 DOI: 10.1111/evo.13445] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 01/16/2018] [Accepted: 01/16/2018] [Indexed: 11/27/2022]
Affiliation(s)
- Xiao-Yue Wang
- Institute of Evolution and Ecology, School of Life Sciences; Central China Normal University; Wuhan 430079 China
- School of Life Science; Guizhou Normal University; Guiyang 550001 China
| | - Qiu-Mei Quan
- College of Environmental Science and Engineering; China West Normal University; Nanchong 637002 China
| | - Bo Wang
- State Key Lab of Hybrid Rice, College of Life Sciences; Wuhan University; Wuhan 430072 China
| | - Yun-Xiang Li
- College of Environmental Science and Engineering; China West Normal University; Nanchong 637002 China
| | - Shuang-Quan Huang
- Institute of Evolution and Ecology, School of Life Sciences; Central China Normal University; Wuhan 430079 China
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Hicks DM, Ouvrard P, Baldock KCR, Baude M, Goddard MA, Kunin WE, Mitschunas N, Memmott J, Morse H, Nikolitsi M, Osgathorpe LM, Potts SG, Robertson KM, Scott AV, Sinclair F, Westbury DB, Stone GN. Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows. PLoS One 2016; 11:e0158117. [PMID: 27341588 PMCID: PMC4920406 DOI: 10.1371/journal.pone.0158117] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 06/12/2016] [Indexed: 11/30/2022] Open
Abstract
Planted meadows are increasingly used to improve the biodiversity and aesthetic amenity value of urban areas. Although many ‘pollinator-friendly’ seed mixes are available, the floral resources these provide to flower-visiting insects, and how these change through time, are largely unknown. Such data are necessary to compare the resources provided by alternative meadow seed mixes to each other and to other flowering habitats. We used quantitative surveys of over 2 million flowers to estimate the nectar and pollen resources offered by two exemplar commercial seed mixes (one annual, one perennial) and associated weeds grown as 300m2 meadows across four UK cities, sampled at six time points between May and September 2013. Nectar sugar and pollen rewards per flower varied widely across 65 species surveyed, with native British weed species (including dandelion, Taraxacum agg.) contributing the top five nectar producers and two of the top ten pollen producers. Seed mix species yielding the highest rewards per flower included Leontodon hispidus, Centaurea cyanus and C. nigra for nectar, and Papaver rhoeas, Eschscholzia californica and Malva moschata for pollen. Perennial meadows produced up to 20x more nectar and up to 6x more pollen than annual meadows, which in turn produced far more than amenity grassland controls. Perennial meadows produced resources earlier in the year than annual meadows, but both seed mixes delivered very low resource levels early in the year and these were provided almost entirely by native weeds. Pollen volume per flower is well predicted statistically by floral morphology, and nectar sugar mass and pollen volume per unit area are correlated with flower counts, raising the possibility that resource levels can be estimated for species or habitats where they cannot be measured directly. Our approach does not incorporate resource quality information (for example, pollen protein or essential amino acid content), but can easily do so when suitable data exist. Our approach should inform the design of new seed mixes to ensure continuity in floral resource availability throughout the year, and to identify suitable species to fill resource gaps in established mixes.
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Affiliation(s)
- Damien M. Hicks
- Institute of Evolutionary Biology, University of Edinburgh, Kings Buildings, Charlotte Auerbach Road, Edinburgh EH9 3JT, United Kingdom
| | - Pierre Ouvrard
- Institute of Evolutionary Biology, University of Edinburgh, Kings Buildings, Charlotte Auerbach Road, Edinburgh EH9 3JT, United Kingdom
- Earth and Life Institute - Agronomy, Université catholique de Louvain, Place Croix du Sud 2, 1348 Louvain-la-Neuve, Belgium
| | - Katherine C. R. Baldock
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQUG, United Kingdom
- Cabot Institute, University of Bristol, Woodland Road, Bristol, BS8 1UJ, United Kingdom
| | - Mathilde Baude
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQUG, United Kingdom
- Collegium Sciences et Techniques, EA 1207 LBLGC, Université d’Orléans, 45067, Orléans, France
| | - Mark A. Goddard
- School of Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - William E. Kunin
- School of Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Nadine Mitschunas
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQUG, United Kingdom
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, RG6 6AR, United Kingdom
| | - Jane Memmott
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQUG, United Kingdom
- Cabot Institute, University of Bristol, Woodland Road, Bristol, BS8 1UJ, United Kingdom
| | - Helen Morse
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQUG, United Kingdom
| | - Maria Nikolitsi
- School of Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Lynne M. Osgathorpe
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQUG, United Kingdom
| | - Simon G. Potts
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, RG6 6AR, United Kingdom
| | | | - Anna V. Scott
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, RG6 6AR, United Kingdom
| | - Frazer Sinclair
- Institute of Evolutionary Biology, University of Edinburgh, Kings Buildings, Charlotte Auerbach Road, Edinburgh EH9 3JT, United Kingdom
- Royal Society for the Protection of Birds, Gola Rainforest National Park, Kenema, Sierra Leone
| | - Duncan B. Westbury
- Institute of Science & the Environment, The University of Worcester, Henwick Grove, Worcester, WR2 6AJ, United Kingdom
| | - Graham N. Stone
- Institute of Evolutionary Biology, University of Edinburgh, Kings Buildings, Charlotte Auerbach Road, Edinburgh EH9 3JT, United Kingdom
- * E-mail:
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19
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Zhang C, Wang LL, Yang YP, Duan YW. Flower evolution of alpine forbs in the open top chambers (OTCs) from the Qinghai-Tibet Plateau. Sci Rep 2015; 5:10254. [PMID: 25998558 PMCID: PMC4441194 DOI: 10.1038/srep10254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 04/08/2015] [Indexed: 11/22/2022] Open
Abstract
Effects of global changes on biodiversity have been paid more and more attention world widely, and the open top chambers (OTCs) are the most common tools to study the effects of climatic warming on plant diversity. However, it remains unclear how flowers evolve under environmental changes, which could help us to understand the changes of plant diversity in the OTCs. We compared the insect diversity and pollen:ovule (P/O) ratio of eight outcrossing species with different life histories inside and outside the OTCs on the Qinghai-Tibet Plateau, to examine the effects induced by OTCs on the evolution of floral traits. In the OTCs, P/O ratio decreased in annuals, but increased in perennials, indicating an overall trend toward selfing in annuals. We found that the insect diversity differed significantly inside and outside the OTCS, with decreases of dipteran insects and bees. We concluded that changes of P/O ratio in the studied plant species might result from pollination failure, which might be the results of mismatch between flowering time and pollinator activities. We also suggested annuals might be in a more extinction risk than perennials in OTCs, if strong inbreeding depression occurs in these annual outcrossing plants.
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Affiliation(s)
- Chan Zhang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Graduate University of the Chinese Academy of Sciences, Beijing 100049, Beijing, P. R. China
| | - Lin-Lin Wang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
| | - Yong-Ping Yang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
| | - Yuan-Wen Duan
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
- Institute of Tibetan Plateau Research at Kunming, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P. R. China
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