title: Environmental versus geographical effects on genomic variation in wild soybean (Glycine soja) across its native range in northeast Asia.
abstract: A fundamental goal in evolutionary biology is to understand how various evolutionary factors interact to affect the population structure of diverse species, especially those of ecological and/or agricultural importance such as wild soybean (Glycine soja). G. soja, from which domesticated soybeans (Glycine max) were derived, is widely distributed throughout diverse habitats in East Asia (Russia, Japan, Korea, and China). Here, we utilize over 39,000 single nucleotide polymorphisms genotyped in 99 ecotypes of wild soybean sampled across their native geographic range in northeast Asia, to understand population structure and the relative contribution of environment versus geography to population differentiation in this species. A STRUCTURE analysis identified four genetic groups that largely corresponded to the geographic regions of central China, northern China, Korea, and Japan, with high levels of admixture between genetic groups. A canonical correlation and redundancy analysis showed that environmental factors contributed 23.6% to population differentiation, much more than that for geographic factors (6.6%). Precipitation variables largely explained divergence of the groups along longitudinal axes, whereas temperature variables contributed more to latitudinal divergence. This study provides a foundation for further understanding of the genetic basis of climatic adaptation in this ecologically and agriculturally important species.
authors.affiliation: Department of Biological Sciences University of North Carolina at Charlotte Charlotte North Carolina 28223.
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Leamy
authors.affiliation: Gregor Mendel Institute of Molecular Plant Biology Vienna A-1030 Austria.
authors.forename: Cheng-Ruei
authors.initials: CR
authors.lastname: Lee
authors.affiliation: Soybean Genomics and Improvement Laboratory Department of Agriculture USDA-Agricultural Research Service Beltsville Maryland 20705.
authors.forename: Qijian
authors.initials: Q
authors.lastname: Song
authors.affiliation: Department of Bioinformatics and Genomics University of North Carolina at Charlotte Charlotte North Carolina 28223.
authors.forename: Ibro
authors.initials: I
authors.lastname: Mujacic
authors.affiliation: Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Yunnan 666303 China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Department of Crop, Soil and Environmental Sciences Auburn University Auburn Alabama 36849.
authors.forename: Charles Y
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Biotechnology Assay and Phenotyping Group Monsanto Company Durham North Carolina 27709.
authors.forename: Changbao
authors.initials: C
authors.lastname: Li
authors.affiliation: Biotechnology Assay and Phenotyping Group Monsanto Company Durham North Carolina 27709.
authors.forename: Susanne
authors.initials: S
authors.lastname: Kjemtrup
authors.affiliation: Department of Biological Sciences University of North Carolina at Charlotte Charlotte North Carolina 28223.
authors.forename: Bao-Hua
authors.initials: BH
authors.lastname: Song
keywords: Admixture; canonical correlation analysis; environment change; gene flow; natural selection; population genomics