Dissemination of soybeans (Glycine max): Seed protein electrophoresis profiles among Japanese cultivars

Seed protein extracts from 477 Japanese soybean cultivars were analyzed by polyaery lamide gel electrophoresis to determine the distribution of the alleles of the Ti (Ti ^a,Ti ^b,Ti ^c) and Sp₁ (Sp ₁ ^a,Sp ₁ ^b loci with respect to maturity group and district of adaptation of each cultivar. About 60 percent of the soybean cultivars had theTi ^a allele. The frequency of theTi ^b allele was found to be highest in the southeast district and lowest in the northeast district. TheTi ^c allele discovered in 6 cultivars was traced to two possible sources adapted in the Tohoku District. TheSp _l ^a, allele was found in 26 cultivars ranging from Maturity Group II through VIII. The summer season type cultivars adapted to the Kyushu District having the genotypeTi ^b Sp_l ^b probably played a major role in the peculiar accumulation of theTi ^ub allele and the decrease of theSp _l ^a allele in the Japanese soybean cultivar population.