Studies on the Evolutionary Relationship among Eco types of G.max and G.soja in China
GAI Jun Yi 1 XU Dong He 1 GAO Zhong 1 Yoshiya Shimamoto 2 Jun Abe 2 Hirofumi Fukushi 2 Shunji Kitajima 2 [WT6BX]( 1 Soybean Research Institute, Nanjing Agriculture University; National Center of Soybean Improvement, Ministry of Agricult
A large sample of various geographical and seasonal eco types of G.max and geographical eco types of G.soja in China was evaluated for their morphological characters, allozyme markers, and RFLP markers of cpDNA and mtDNA, which were thought to be neutral to artificial selection,in order to reveal the evolutionary relationship among them. The results obtained were as follows: (1) There existed significant geographical differentiation among regions as well as seasonal differentiation within a region in G.max. The genetic distance between southern China spring type and Northeast China spring type was larger than those among seasonal types within southern China even though the former two were in similar maturity groups. (2) The evolutionary tendency from late maturity to early maturity was detected no matter it was with the geographical or seasonal eco type of G.max . The genetic distances between all types of G.max of the three regions and southern China G.soja population were closer than those between the regional population of G.max and their respective G.soja counterpart, indicating that the primitive southern China G.soja population might be the common ancestor of all the cultivated soybean in the three regions and the original cultivated soybean might differentiate into earlier maturity types with less sensitivity to day length during its dissemination northward.