Characterizing the cytoplasmic diversity and phyletic relationship of Chinese landraces of soybean, Glycine max, based on RFLPs of chloroplast and mitochondrial DNA

Restriction fragment-length polymorphism (RFLP) of chloroplast and mitochondrial DNA of many soybean landraces were analyzed to characterize their cytoplasmic genome and to consider the diversity and phylogeny of soybean in China. Three chloroplast and five mitochondrial types were distinguished, and seven cytoplasmic genome types were observed in different combinations in specimens collected from China. The cytoplasmic genome diversity was higher at the Yangtze River Valley. The main group of cytoplasmic genomes was composed of five types related phylogenetically and occurred in the southern region of China. Two unique types were very different in cytoplasmic genome constitution from each other and from the main group. They were considered to be derived from wild plants with the same cytoplasmic genome and to occur in two remote regions, the northern region and the Yangtze River Valley of China, respectively. Therefore, when considered with regard to the cytoplasmic genome of soybean landraces detected in China, seven genome types are distinguished, some types may be assumed to have arisen in wild soybean before domestication; and the Yangtze River Valley is the center of cytoplasmic diversity of the soybean.