TESTS OF LINKAGE OF ISOZYME LOCI WITH 5 PRIMARY TRISOMICS IN SOYBEAN, GLYCINE-MAX (L) MERR

In a number of plant species, primary trisomics have been used to establish the chromosomal location of genes and to consolidate linkage maps. In soybean, Glycine max (L.) Merr., five of a possible 20 primary trisomics have been characterized. In this study, chromosomal locations of several isozyme loci were investigated by using the primary trisomics A, B, C, D, and S. Only one locus, Dia 1 (diaphorase), had segregation ratios in the F2 progeny of trisomic F1 hybrids that were significantly different from disomic segregation ratios. In crosses of four different disomic lines by Trisomic D, F2 segregation ratios fit a trisomic segregation ratio, thereby indicating that Dia1, which has not been mapped to a linkage group, was located on the extra chromosome in Trisomic D. In all other linkage tests, loci were not associated with a primary trisomic.