Studies on the evolutionary relationship among eco-types of G. max and G. soja in China

(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.