From wild to cultivated varieties: The genetic variation and genomic domestication of Medicago polymorpha in China

Medicago polymorpha is a successful invasive plant and widespread around the world with its ability to adapt to the novel environment conditions quickly. However, the evolutionary dynamics after invasion still largely unclear so far. In this study, we performed a specific-length amplified fragments sequencing (SLAF-seq) of ten representative Medicago polymorpha accessions enrolled from different regions in China to infer the population structure and nucleotide diversity. As a result, total 52,237 high-quality cross-species SNPs were identified. Population structure analysis based on these SNPs suggested entire Medicago polymorpha accessions could be divided into three groups, that is consistent with wild, intermediate, and cultivated. Moreover, a low level of gene flow occurred between cultivated and wild subgroups, and the wild subgroup had a higher allelic variation than the cultivated subgroup, which indicated that a genetic bottleneck may occurred during Medicago polymorpha domestic...