Fig. 4

Exemplification of introgression and putative origins of introgression illustrated by relative identical by descent (rIBD). a–c Genomic component along chromosome 2 in three related accessions Heihexiaohuangdou, PI 578357, and PI 522226. A G. soja accession (b) carries introgressed G. max fragments sharing the highest similarity to the corresponding regions of a landrace (a), and the G. soja segments sharing highest similarity to the corresponding regions of a G. soja accession (c). d The cladogram tree based on SNPs in the introgression regions of chromosome 2 showing the G. max (Heihexiaohuangdou, blue) origin of the regions in G. soja accession PI 578357, as pointed by the arrow. e The cladogram tree based on SNPs in the non-introgression regions showing the G. soja (PI 522226, red) origin of the regions in PI 578357, as pointed by the arrow. f Geographic distribution of the three related accessions. g–i Genomic component along chromosome 19 in three related accessions PI 548456, PI 339734, and PI 407275. A G. max accession (h) carries introgressed G. soja fragments sharing the highest similarity to the corresponding regions of a G. soja accession (i) and the G. max segments sharing the highest similarity to the corresponding regions of a G. max accession (g). j The cladogram tree based on SNPs in the non-introgression regions showing the G. max (PI 548456, blue) origin of the regions in PI 339734, as pointed by the arrow. k The cladogram tree based on SNPs in the introgression regions of chromosome 2 showing the G. soja (PI 407275, red) origin of the regions in G. max accession PI 339734, as pointed by the arrow. l Geographic distribution of the three related accessions