Distribution of a Trypsin Inhibitor Variant in Seed Proteins of Soybean Varieties¹

Abstract

Studies on the polymorphic nature of the soybean trypsin inhibitor protein revealed that 20 out of 294 soybean ( Glycine max [L.] Merrill) varieties sampled had Rf 0.92 electrophoretic bands, while the rest had Rf 0.95 bands. The frequency for Rf 0.92 was 0.07 and for Rf 0.95, it was 0.93. Soybean varieties, whose origins were known, that had the Rf 0.92 band were from Japan or Korea, but not all soybeans from Japan or Korea had this band. Varieties with the Rf 0.95 band, the only type found in Chinesederived germ plasm, also came from Japan and Korea. Most of the varieties with the Rf 0.92 band are in Maturity Groups I through IV.