Chromosome Reshuffling Patterns of Korean Soybean Cultivars using Genome-wide 202 InDel Markers

Knowledge of the chromosomal constitution of the ancestors of modern soybean will complement plant breeding efforts to improve agronomic and economic characteristics of soybean. Variation block (VB)-based comparison using genome-wide insertion/deletion (InDel) markers was used on a diverse panel of 147 soybean cultivars to assess the impact of chromosomal changes during modern breeding. There were identical variation patterns of the examined InDels consistently appearing in the genome parts arising from parental varieties, indicating that soybean chromosomes in descendants should be all determined by genetic reshuffling of VBs inherited from parental chromosomes. Structure analysis of the accessions through the 202 InDels separated the accessions into four subgroups. Gene introgression revealed by the structure analysis agreed with the fact that a limited number of landraces and elite varieties were introduced and used as donors for breeding soybean cultivars in pedigree analysis. Especially, VBs became more reshuffled over time as a result of the breeding process, which resulted in using breeding parents with new VB-types for improving the end-use value of soybean. Therefore, their clustering using the 202 VB-specific InDels is strongly influenced by the difference in breeding ancestors among the subgroups. This indicates that the 202 InDel markers are very useful for genetic study by analyzing the reshuffling patterns of the parental genomes in the descendant.