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Lee Y, Thieme T, Kim H. Complex evolution in Aphis gossypii group (Hemiptera: Aphididae), evidence of primary host shift and hybridization between sympatric species. PLoS One 2021; 16:e0245604. [PMID: 33539375 PMCID: PMC7861460 DOI: 10.1371/journal.pone.0245604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 01/05/2021] [Indexed: 11/17/2022] Open
Abstract
Aphids provide a good model system to understand the ecological speciation concept, since the majority of the species are host-specific, and they spend their entire lifecycle on certain groups of host plants. Aphid species that apparently have wide host plant ranges have often turned out to be complexes of host-specialized biotypes. Here we investigated the various host-associated populations of the two recently diverged species, Aphis gossypii and A. rhamnicola, having multiple primary hosts, to understand the complex evolution with host-associated speciation. Using mitochondrial DNA marker and nine microsatellite loci, we reconstructed the haplotype network, and analyzed the genetic structure and relationships. Approximate Bayesian computation was also used to infer the ancestral primary host and host-associated divergence, which resulted in Rhamnus being the most ancestral host for A. gossypii and A. rhamnicola. As a result, Aphis gossypii and A. rhamnicola do not randomly use their primary and secondary host plants; rather, certain biotypes use only some secondary and specific primary hosts. Some biotypes are possibly in a diverging state through specialization to specific primary hosts. Our results also indicate that a new heteroecious race can commonly be derived from the heteroecious ancestor, showing strong evidence of ecological specialization through a primary host shift in both A. gossypii and A. rhamnicola. Interestingly, A. gossypii and A. rhamnicola shared COI haplotypes with each other, thus there is a possibility of introgression by hybridization between them by cross-sharing same primary hosts. Our results contribute to a new perspective in the study of aphid evolution by identifying complex evolutionary trends in the gossypii sensu lato complex.
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Affiliation(s)
- Yerim Lee
- Animal Systematics Laboratory, Department of Biology, Kunsan National University, Gunsan, Republic of Korea
| | - Thomas Thieme
- BTL Bio-Test Labor GmbH Sagerheide, RG Phyto-Entomology, Gross Lüsewitz, Germany
| | - Hyojoong Kim
- Animal Systematics Laboratory, Department of Biology, Kunsan National University, Gunsan, Republic of Korea
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Enders LS, Rault LC, Heng-Moss TM, Siegfried BD, Miller NJ. Transcriptional responses of soybean aphids to sublethal insecticide exposure. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 118:103285. [PMID: 31760137 DOI: 10.1016/j.ibmb.2019.103285] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 11/07/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
Insecticides are a key tool in the management of many insect pests of agriculture, including soybean aphids. The selection imposed by insecticide use has often lead to the evolution of resistance by the target pest through enhanced detoxification mechanisms. We hypothesised that exposure of insecticide-susceptible aphids to sublethal doses of insecticides would result in the up-regulation of genes involved in detoxification of insecticides, revealing the genes upon which selection might act in the field. We used the soybean aphid biotype 1 reference genome, version 6.0 as a reference to analyze RNA-Seq data. We identified multiple genes with potential detoxification roles that were up-regulated 12 h after sublethal exposure to esfenvalerate or thiamethoxam. However, these genes were part of a dramatic burst of differential gene expression in which thousands of genes were up- or down-regulated, rather than a defined response to insecticides. Interestingly, the transcriptional burst observed at 12 h s declined dramatically by 24-hrs post-exposure, suggesting a general stress response that may become fine-tuned over time.
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Affiliation(s)
- Laramy S Enders
- Department of Entomology, University of Nebraska-Lincoln, Entomology Hall, Lincoln, NE, 68583, USA; Department of Entomology, Purdue University, 901 W State St, West Lafayette, IN, 47907, USA
| | - Leslie C Rault
- Department of Entomology, University of Nebraska-Lincoln, Entomology Hall, Lincoln, NE, 68583, USA
| | - Tiffany M Heng-Moss
- Department of Entomology, University of Nebraska-Lincoln, Entomology Hall, Lincoln, NE, 68583, USA
| | - Blair D Siegfried
- Department of Entomology, University of Nebraska-Lincoln, Entomology Hall, Lincoln, NE, 68583, USA; Department of Entomology and Nematology, University of Florida, 1881 Natural Area Drive, Gainesville, FL, 32611, USA
| | - Nicholas J Miller
- Department of Entomology, University of Nebraska-Lincoln, Entomology Hall, Lincoln, NE, 68583, USA; Department of Biology, Illinois Institute of Technology, 3101 S Dearborn St, Chicago, IL, 60616, USA.
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Leite NA, Correa AS, Michel AP, Alves-Pereira A, Pavinato VAC, Zucchi MI, Omoto C. Pan-American Similarities in Genetic Structures of Helicoverpa armigera and Helicoverpa zea (Lepidoptera: Noctuidae) With Implications for Hybridization. ENVIRONMENTAL ENTOMOLOGY 2017; 46:1024-1034. [PMID: 28498959 DOI: 10.1093/ee/nvx088] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Indexed: 06/07/2023]
Abstract
The genus Helicoverpa (Lepidoptera: Noctuidae) includes phytophagous and polyphagous agricultural insect pests. In the Americas, a native pest, Helicoverpa zea (Boddie), and an invasive pest, Helicoverpa armigera (Hübner), are causing severe damage in vegetable and agronomic crops. The population structure of both species in South America is poorly understood, and the phylogenetic relatedness of H. armigera and H. zea suggests natural interspecific gene flow between these species. Using microsatellite loci, we investigated: 1) the genetic diversity and gene flow of H. armigera specimens from Brazil; 2) the genetic diversity and gene flow between H. zea specimens from Brazil and the United States; and 3) the possibility of interspecific gene flow and the frequency of putative hybrids in Brazil. We detected high intraspecific gene flow among populations collected in the same country. However, there is a geographic limit to gene flow among H. zea individuals from South and North America. Pairwise Fst and private alleles showed that H. armigera is more similar to H. zea from Brazil than H. zea from the United States. A comparative STRUCTURE analysis suggests natural hybridization between H. armigera and H. zea in Brazil. High gene flow and natural hybridization are key traits to population adaptation in new and disturbed environments, which can influence the management of these pests in the American continent.
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Affiliation(s)
- N A Leite
- Department of Entomology and Acarology, "Luiz de Queiroz" College of Agriculture (ESALQ/USP), Av. Pádua Dias 11, Piracicaba, SP 13418-900, Brazil
| | - A S Correa
- Department of Entomology and Acarology, "Luiz de Queiroz" College of Agriculture (ESALQ/USP), Av. Pádua Dias 11, Piracicaba, SP 13418-900, Brazil
| | - A P Michel
- Department of Entomology, Ohio Agricultural Research and Development Center, Thorne Hall, The Ohio State University, 1680 Madison Ave., Wooster, OH 44691
| | - A Alves-Pereira
- Department of Genetics, "Luiz de Queiroz" College of Agriculture (ESALQ/USP), Av. Pádua Dias 11, Piracicaba, SP 13418-900, Brazil
| | - V A C Pavinato
- Department of Entomology, Ohio Agricultural Research and Development Center, Thorne Hall, The Ohio State University, 1680 Madison Ave., Wooster, OH 44691
| | - M I Zucchi
- Paulista Technology Agency of Agribusiness, Rodovia SP 127, Vila Fátima, Piracicaba, SP 13400-970, Brazil
| | - C Omoto
- Department of Entomology and Acarology, "Luiz de Queiroz" College of Agriculture (ESALQ/USP), Av. Pádua Dias 11, Piracicaba, SP 13418-900, Brazil
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Kim H, Hoelmer KA, Lee S. Population genetics of the soybean aphid in North America and East Asia: test for introduction between native and introduced populations. Biol Invasions 2016. [DOI: 10.1007/s10530-016-1299-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Enders LS, Miller NJ. Stress-induced changes in abundance differ among obligate and facultative endosymbionts of the soybean aphid. Ecol Evol 2016; 6:818-29. [PMID: 26865969 PMCID: PMC4739556 DOI: 10.1002/ece3.1908] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 11/25/2015] [Accepted: 11/27/2015] [Indexed: 12/17/2022] Open
Abstract
Bacterial endosymbionts can drive evolutionary novelty by conferring adaptive benefits under adverse environmental conditions. Among aphid species there is growing evidence that symbionts influence tolerance to various forms of stress. However, the extent to which stress inflicted on the aphid host has cascading effects on symbiont community dynamics remains poorly understood. Here we simultaneously quantified the effect of host-plant induced and xenobiotic stress on soybean aphid (Aphis glycines) fitness and relative abundance of its three bacterial symbionts. Exposure to soybean defensive stress (Rag1 gene) and a neurotoxic insecticide (thiamethoxam) substantially reduced aphid composite fitness (survival × reproduction) by 74 ± 10% and 92 ± 2%, respectively, which in turn induced distinctive changes in the endosymbiont microbiota. When challenged by host-plant defenses a 1.4-fold reduction in abundance of the obligate symbiont Buchnera was observed across four aphid clonal lines. Among facultative symbionts of Rag1-stressed aphids, Wolbachia abundance increased twofold and Arsenophonus decreased 1.5-fold. A similar pattern was observed under xenobiotic stress, with Buchnera and Arsenophonus titers decreasing (1.3-fold) and Wolbachia increasing (1.5-fold). Furthermore, variation in aphid virulence to Rag1 was positively correlated with changes in Arsenophonus titers, but not Wolbachia or Buchnera. A single Arsenophonus multi-locus genotype was found among aphid clonal lines, indicating strain diversity is not primarily responsible for correlated host-symbiont stress levels. Overall, our results demonstrate the nature of aphid symbioses can significantly affect the outcome of interactions under stress and suggests general changes in the microbiome can occur across multiple stress types.
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Affiliation(s)
- Laramy S. Enders
- Department of EntomologyUniversity of Nebraska‐Lincoln103 Entomology HallLincolnNebraska68583‐0816
| | - Nicholas J. Miller
- Department of EntomologyUniversity of Nebraska‐Lincoln103 Entomology HallLincolnNebraska68583‐0816
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Enders L, Bickel R, Brisson J, Heng-Moss T, Siegfried B, Zera A, Miller N. Soybean aphid (Hemiptera: Aphididae) response to soybean plant defense: stress levels, tradeoffs, and cross-virulence. ENVIRONMENTAL ENTOMOLOGY 2014; 43:47-57. [PMID: 24472201 DOI: 10.1603/en13135] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A variety of management methods to control the soybean aphid (Aphis glycines Matsumura) have been investigated since its invasion into North America in 2000, among them plant resistance has emerged as a viable option for reducing aphid damage to soybeans and preventing outbreaks. Plant resistance methods often use natural soybean plant defenses that impose stress on aphids by reducing fitness and altering behavior. Research efforts have heavily focused on identification and development of aphid resistant soybean varieties, leaving much unknown about soybean aphid response to stressful host plant defenses. In this study, we aimed to 1) evaluate lifetime fitness consequences and phenotypic variation in response to host plant-induced stress and 2) investigate whether trade-offs involving fitness costs and/or cross-virulence to multiple antibiotic soybean varieties exists. We compared aphid survival and reproduction during and after a short period of exposure to soybeans with the Rag2 resistance gene and measured aphid clonal variation in response to Rag2 soybeans. In addition, we measured the performance of Rag2 virulent and avirulent aphids on five soybean varieties with various forms of antibiotic resistance. Our results indicate that plant defenses impose high levels of stress and have long-term fitness consequences, even after aphids are removed from resistant plants. We identified one aphid clone that was able to colonize Rag2 among the seven clones tested, suggesting that virulent genotypes may be prevalent in natural populations. Finally, although we did not find evidence of cross-virulence to multiple antibiotic soybean varieties, our results suggest independent mechanisms of aphid virulence to Rag1 and Rag2 that may involve fitness costs.
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Affiliation(s)
- Laramy Enders
- Department of Entomology, University of Nebraska-Lincoln, 103 Entomology Hall, Lincoln, NE 68583-0816, USA
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Orantes LC, Zhang W, Mian MAR, Michel AP. Maintaining genetic diversity and population panmixia through dispersal and not gene flow in a holocyclic heteroecious aphid species. Heredity (Edinb) 2012; 109:127-34. [PMID: 22549514 PMCID: PMC3400749 DOI: 10.1038/hdy.2012.21] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 03/20/2012] [Accepted: 03/22/2012] [Indexed: 11/08/2022] Open
Abstract
Heteroecious holocyclic aphids exhibit both sexual and asexual reproduction and alternate among primary and secondary hosts. Most of these aphids can feed on several related hosts, and invasions to new habitats may limit the number of suitable hosts. For example, the aphid specialist Aphis glycines survives only on the primary host buckthorn (Rhamnus spp.) and the secondary host soybean (Glycine max) in North America where it is invasive. Owing to this specialization and sparse primary host distribution, host colonization events could be localized and involve founder effects, impacting genetic diversity, population structure and adaptation. We characterized changes in the genetic diversity and structure across time among A. glycines populations. Populations were sampled from secondary hosts twice in the same geographical location: once after secondary colonization (early season), and again immediately before primary host colonization (late season). We tested for evidence of founder effects and genetic isolation in early season populations, and whether or not late-season dispersal restored genetic diversity and reduced fragmentation. A total of 24 single-nucleotide polymorphisms and 6 microsatellites were used for population genetic statistics. We found significantly lower levels of genotypic diversity and more genetic isolation among early season collections, indicating secondary host colonization occurred locally and involved founder effects. Pairwise F(ST) decreased from 0.046 to 0.017 in early and late collections, respectively, and while genetic relatedness significantly decreased with geographical distance in early season collections, no spatial structure was observed in late-season collections. Thus, late-season dispersal counteracts the secondary host colonization through homogenization and increases genetic diversity before primary host colonization.
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Affiliation(s)
- L C Orantes
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA
| | - W Zhang
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA
| | - M A R Mian
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA
- USDA-ARS and Department of Horticulture and Crop Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA
| | - A P Michel
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA
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Jun TH, Michel AP, Mian MAR. Development of soybean aphid genomic SSR markers using next generation sequencing. Genome 2011; 54:360-7. [PMID: 21529140 DOI: 10.1139/g11-002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Simple sequence repeats (SSRs) or microsatellites are very useful molecular markers, owing to their locus-specific codominant and multiallelic nature, high abundance in the genome, and high rates of transferability across species. The soybean aphid (Aphis glycines Matsumura) has become the most damaging insect pest of soybean (Glycine max (L.) Merr.) in North America, since it was first found in the Midwest of the United States in 2000. Biotypes of the soybean aphid capable of colonizing newly developed aphid-resistant soybean cultivars have been recently discovered. Genetic resources, including molecular markers, to study soybean aphids are severely lacking. Recently developed next generation sequencing platforms offer opportunities for high-throughput and inexpensive genome sequencing and rapid marker development. The objectives of this study were (i) to develop and characterize genomic SSR markers from soybean aphid genomic sequences generated by next generation sequencing technology and (ii) to evaluate the utility of the SSRs for genetic diversity or relationship analyses. In total 128 SSR primer pairs were designed from sequences generated by Illumina GAII from a reduced representation library of A. glycines. Nearly 94% (120) of the primer pairs amplified SSR alleles of expected size and 24 SSR loci were polymorphic among three aphid samples from three populations. The polymorphic SSRs were successfully used to differentiate among 24 soybean aphids from Ohio and South Dakota. Sequencing of PCR products of two SSR markers from four aphid samples revealed that the allelic polymorphism was due to variation in the SSR repeats among the aphids. These markers should be particularly useful for genetic differentiation among aphids collected from soybean fields at different localities and regions. These SSR markers provide the soybean aphid research community with the first set of PCR-based codominant markers developed from the genomic sequences of A. glycines.
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Affiliation(s)
- Tae-Hwan Jun
- Department of Entomology, The Ohio State University - Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA
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Bai X, Rivera-Vega L, Mamidala P, Bonello P, Herms DA, Mittapalli O. Transcriptomic signatures of ash (Fraxinus spp.) phloem. PLoS One 2011; 6:e16368. [PMID: 21283712 PMCID: PMC3025028 DOI: 10.1371/journal.pone.0016368] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 12/26/2010] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Ash (Fraxinus spp.) is a dominant tree species throughout urban and forested landscapes of North America (NA). The rapid invasion of NA by emerald ash borer (Agrilus planipennis), a wood-boring beetle endemic to Eastern Asia, has resulted in the death of millions of ash trees and threatens billions more. Larvae feed primarily on phloem tissue, which girdles and kills the tree. While NA ash species including black (F. nigra), green (F. pennsylvannica) and white (F. americana) are highly susceptible, the Asian species Manchurian ash (F. mandshurica) is resistant to A. planipennis perhaps due to their co-evolutionary history. Little is known about the molecular genetics of ash. Hence, we undertook a functional genomics approach to identify the repertoire of genes expressed in ash phloem. METHODOLOGY AND PRINCIPAL FINDINGS Using 454 pyrosequencing we obtained 58,673 high quality ash sequences from pooled phloem samples of green, white, black, blue and Manchurian ash. Intriguingly, 45% of the deduced proteins were not significantly similar to any sequences in the GenBank non-redundant database. KEGG analysis of the ash sequences revealed a high occurrence of defense related genes. Expression analysis of early regulators potentially involved in plant defense (i.e. transcription factors, calcium dependent protein kinases and a lipoxygenase 3) revealed higher mRNA levels in resistant ash compared to susceptible ash species. Lastly, we predicted a total of 1,272 single nucleotide polymorphisms and 980 microsatellite loci, among which seven microsatellite loci showed polymorphism between different ash species. CONCLUSIONS AND SIGNIFICANCE The current transcriptomic data provide an invaluable resource for understanding the genetic make-up of ash phloem, the target tissue of A. planipennis. These data along with future functional studies could lead to the identification/characterization of defense genes involved in resistance of ash to A. planipennis, and in future ash breeding programs for marker development.
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Affiliation(s)
- Xiaodong Bai
- Department of Entomology, The Ohio State University, Ohio Agricultural and Research Development Center, Wooster, Ohio, United States of America
| | - Loren Rivera-Vega
- Department of Entomology, The Ohio State University, Ohio Agricultural and Research Development Center, Wooster, Ohio, United States of America
| | - Praveen Mamidala
- Department of Entomology, The Ohio State University, Ohio Agricultural and Research Development Center, Wooster, Ohio, United States of America
| | - Pierluigi Bonello
- Department of Plant Pathology, The Ohio State University, Columbus, Ohio, United States of America
| | - Daniel A. Herms
- Department of Entomology, The Ohio State University, Ohio Agricultural and Research Development Center, Wooster, Ohio, United States of America
| | - Omprakash Mittapalli
- Department of Entomology, The Ohio State University, Ohio Agricultural and Research Development Center, Wooster, Ohio, United States of America
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Ragsdale DW, Landis DA, Brodeur J, Heimpel GE, Desneux N. Ecology and management of the soybean aphid in North America. ANNUAL REVIEW OF ENTOMOLOGY 2011; 56:375-99. [PMID: 20868277 DOI: 10.1146/annurev-ento-120709-144755] [Citation(s) in RCA: 225] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The soybean aphid, Aphis glycines Matsumura, has become the single most important arthropod pest of soybeans in North America. Native to Asia, this invasive species was first discovered in North America in July 2000 and has rapidly spread throughout the northcentral United States, much of southeastern Canada, and the northeastern United States. In response, important elements of the ecology of the soybean aphid in North America have been elucidated, with economic thresholds, sampling plans, and chemical control recommendations widely adopted. Aphid-resistant soybean varieties were available to growers in 2010. The preexisting community of aphid natural enemies has been highly effective in suppressing aphid populations in many situations, and classical biological control efforts have focused on the addition of parasitoids of Asian origin. The keys to sustainable management of this pest include understanding linkages between the soybean aphid and other introduced and native species in a landscape context along with continued development of aphid-resistant varieties.
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Affiliation(s)
- David W Ragsdale
- Department of Entomology, University of Minnesota, St. Paul, Minnesota 55108, USA.
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Michel AP, Zhang W, Mian MAR. Genetic diversity and differentiation among laboratory and field populations of the soybean aphid, Aphis glycines. BULLETIN OF ENTOMOLOGICAL RESEARCH 2010; 100:727-734. [PMID: 20507673 DOI: 10.1017/s000748531000012x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The soybean aphid, Aphis glycines Matsumura, is a recent invasive pest of soybean in North America. Currently, much research is focused on developing and characterizing soybean cultivars expressing host-plant resistance. During the initial phases of host-plant resistance screening, many of these studies use soybean aphid laboratory populations. Previous studies in other systems have documented substantial differences among laboratory and field populations. Whether or not this pattern exists in A. glycines is unknown, but it is extremely important when estimating the level of selection and virulence to host-plant resistant soybeans. In this study, we used seven microsatellite markers to estimate and compare genetic diversity and differentiation among five laboratory and 12 field populations. Our results indicate that soybean aphid laboratory populations are severely lacking in genotypic diversity and show extreme genetic differentiation among each other and to field populations. Continued use of laboratory populations for initial soybean aphid resistance screening could lead to erroneous estimations of the potential success for host-plant resistance.
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Affiliation(s)
- A P Michel
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, 1680 Madison Avenue, Wooster, OH 44691, USA.
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Michel AP, Zhang W, Kyo Jung J, Kang ST, Mian MAR. Population genetic structure of Aphis glycines. ENVIRONMENTAL ENTOMOLOGY 2009; 38:1301-1311. [PMID: 19689913 DOI: 10.1603/022.038.0442] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The soybean aphid (Aphis glycines Matsumura) is an invasive pest of cultivated soybean (Glycine max L.) in North America. After the initial invasion in 2000, the aphid has quickly spread across most of the United States and Canada, suggesting large-scale dispersal and rapid adaptation to new environments. Using microsatellite markers from closely related species, we compared the genetic diversity and the amount of genetic differentiation within and among 2 South Korean and 10 North American populations. Overall allelic polymorphism was low, never exceeding four alleles per locus. However, differences in genetic diversity were seen among South Korean and North American populations in terms of heterozygote excesses and genotypic richness. Within North America, two populations (Michigan and Ontario), had lower genetic diversities and exhibited high genetic differentiation compared with the remaining eight populations. The earlier collection time of Michigan and Ontario samples explained the genetic differences better than geographic subdivisions. These data indicate a pattern of small colonizing populations on soybeans, followed by rapid clonal amplification and subsequent large-scale dispersal across North America.
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Affiliation(s)
- Andrew P Michel
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA.
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