Decomposing Additive Genetic Variance Revealed Novel Insights into Trait Evolution in Synthetic Hexaploid Wheat
Whole genome duplication (WGD) is an evolutionary phenomenon, which causes significant changes to genomic structure and trait architecture. In recent years, a number of studies decomposed the additive genetic variance explained by different sets of variants. However, they investigated diploid popula...
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Frontiers Media S.A.
2018-02-01
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| Series: | Frontiers in Genetics |
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| Online Access: | http://journal.frontiersin.org/article/10.3389/fgene.2018.00027/full |
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| author | Abdulqader Jighly Abdulqader Jighly Reem Joukhadar Reem Joukhadar Sukhwinder Singh Francis C. Ogbonnaya |
| author_facet | Abdulqader Jighly Abdulqader Jighly Reem Joukhadar Reem Joukhadar Sukhwinder Singh Francis C. Ogbonnaya |
| author_sort | Abdulqader Jighly |
| collection | DOAJ |
| description | Whole genome duplication (WGD) is an evolutionary phenomenon, which causes significant changes to genomic structure and trait architecture. In recent years, a number of studies decomposed the additive genetic variance explained by different sets of variants. However, they investigated diploid populations only and none of the studies examined any polyploid organism. In this research, we extended the application of this approach to polyploids, to differentiate the additive variance explained by the three subgenomes and seven sets of homoeologous chromosomes in synthetic allohexaploid wheat (SHW) to gain a better understanding of trait evolution after WGD. Our SHW population was generated by crossing improved durum parents (Triticum turgidum; 2n = 4x = 28, AABB subgenomes) with the progenitor species Aegilops tauschii (syn Ae. squarrosa, T. tauschii; 2n = 2x = 14, DD subgenome). The population was phenotyped for 10 fungal/nematode resistance traits as well as two abiotic stresses. We showed that the wild D subgenome dominated the additive effect and this dominance affected the A more than the B subgenome. We provide evidence that this dominance was not inflated by population structure, relatedness among individuals or by longer linkage disequilibrium blocks observed in the D subgenome within the population used for this study. The cumulative size of the three homoeologs of the seven chromosomal groups showed a weak but significant positive correlation with their cumulative explained additive variance. Furthermore, an average of 69% for each chromosomal group's cumulative additive variance came from one homoeolog that had the highest explained variance within the group across all 12 traits. We hypothesize that structural and functional changes during diploidization may explain chromosomal group relations as allopolyploids keep balanced dosage for many genes. Our results contribute to a better understanding of trait evolution mechanisms in polyploidy, which will facilitate the effective utilization of wheat wild relatives in breeding. |
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| institution | Directory Open Access Journal |
| issn | 1664-8021 |
| language | English |
| last_indexed | 2024-12-13T06:50:19Z |
| publishDate | 2018-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Genetics |
| spelling | doaj.art-ad2890c321024bebb67eef2468b168b22022-12-21T23:56:09ZengFrontiers Media S.A.Frontiers in Genetics1664-80212018-02-01910.3389/fgene.2018.00027310140Decomposing Additive Genetic Variance Revealed Novel Insights into Trait Evolution in Synthetic Hexaploid WheatAbdulqader Jighly0Abdulqader Jighly1Reem Joukhadar2Reem Joukhadar3Sukhwinder Singh4Francis C. Ogbonnaya5Agriculture Victoria, Agriculture Research Division, AgriBio, Centre for AgriBiosciences, Bundoora, VIC, AustraliaSchool of Applied Systems Biology, La Trobe University, Bundoora, VIC, AustraliaAgriculture Victoria, Agriculture Research Division, AgriBio, Centre for AgriBiosciences, Bundoora, VIC, AustraliaDepartment of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC, AustraliaInternational Maize and Wheat Improvement Center (CIMMYT), Texcoco, MexicoGrains Research and Development Corporation, Kingston, ACT, AustraliaWhole genome duplication (WGD) is an evolutionary phenomenon, which causes significant changes to genomic structure and trait architecture. In recent years, a number of studies decomposed the additive genetic variance explained by different sets of variants. However, they investigated diploid populations only and none of the studies examined any polyploid organism. In this research, we extended the application of this approach to polyploids, to differentiate the additive variance explained by the three subgenomes and seven sets of homoeologous chromosomes in synthetic allohexaploid wheat (SHW) to gain a better understanding of trait evolution after WGD. Our SHW population was generated by crossing improved durum parents (Triticum turgidum; 2n = 4x = 28, AABB subgenomes) with the progenitor species Aegilops tauschii (syn Ae. squarrosa, T. tauschii; 2n = 2x = 14, DD subgenome). The population was phenotyped for 10 fungal/nematode resistance traits as well as two abiotic stresses. We showed that the wild D subgenome dominated the additive effect and this dominance affected the A more than the B subgenome. We provide evidence that this dominance was not inflated by population structure, relatedness among individuals or by longer linkage disequilibrium blocks observed in the D subgenome within the population used for this study. The cumulative size of the three homoeologs of the seven chromosomal groups showed a weak but significant positive correlation with their cumulative explained additive variance. Furthermore, an average of 69% for each chromosomal group's cumulative additive variance came from one homoeolog that had the highest explained variance within the group across all 12 traits. We hypothesize that structural and functional changes during diploidization may explain chromosomal group relations as allopolyploids keep balanced dosage for many genes. Our results contribute to a better understanding of trait evolution mechanisms in polyploidy, which will facilitate the effective utilization of wheat wild relatives in breeding.http://journal.frontiersin.org/article/10.3389/fgene.2018.00027/fullpolyploidysynthetic hexaploid wheatdiploidizationadditive varianceheritability |
| spellingShingle | Abdulqader Jighly Abdulqader Jighly Reem Joukhadar Reem Joukhadar Sukhwinder Singh Francis C. Ogbonnaya Decomposing Additive Genetic Variance Revealed Novel Insights into Trait Evolution in Synthetic Hexaploid Wheat Frontiers in Genetics polyploidy synthetic hexaploid wheat diploidization additive variance heritability |
| title | Decomposing Additive Genetic Variance Revealed Novel Insights into Trait Evolution in Synthetic Hexaploid Wheat |
| title_full | Decomposing Additive Genetic Variance Revealed Novel Insights into Trait Evolution in Synthetic Hexaploid Wheat |
| title_fullStr | Decomposing Additive Genetic Variance Revealed Novel Insights into Trait Evolution in Synthetic Hexaploid Wheat |
| title_full_unstemmed | Decomposing Additive Genetic Variance Revealed Novel Insights into Trait Evolution in Synthetic Hexaploid Wheat |
| title_short | Decomposing Additive Genetic Variance Revealed Novel Insights into Trait Evolution in Synthetic Hexaploid Wheat |
| title_sort | decomposing additive genetic variance revealed novel insights into trait evolution in synthetic hexaploid wheat |
| topic | polyploidy synthetic hexaploid wheat diploidization additive variance heritability |
| url | http://journal.frontiersin.org/article/10.3389/fgene.2018.00027/full |
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