Inheritance and variation of amylase in cultivated and wild soybeans and their wild relatives

Abstract

The activity of amylase at Am-1 and Am- 2 loci represents α-amylase while that at Am-3 locus represents B-amylase. In transmisions, the three loci usually behave as a single unit. The Am-3 locus has four variants F, S, S^w and n₁ which are allelic in their effects on Am-3. Fand the S are codominant; S^w is recessive to F and the S₁ but dominant over n₁. The n₁ variant may be a recent mutation that occurred in the cultivar Altona. In cultivated soybeans (G. max) only 0.42 percent of heterozygous seed were detected among 1905 seed from 176 cultivars. These heterozygous seed represent the product of natural outcrossing. The wild soybean (G. soja) seed collected from Japan and Korea showed 31.8 percent and 25.7 percent polymorphism, respectively. The average heterozygosity is 8.1 percent and 7.4 percent for Japanese and Korean collections, respectively. Seed of Neo-notonia wightii show no amylase activity except in two accessions from South Africa.