Genotype × Environment Interactions for Protein in Glycine max × Glycine soja crosses1

Abstract

One hundred fifteen F3 families chosen from four crosses between Glycine max (L.) Merr. and its wild relative, Glycine soja Sieb. and Zucc., were used in two studies to evaluate the effect of genotype × environment interactions on the protein content of soybean seeds. The families ranged in protein content from approximately 40 to 50%.The first study was a variance component approach composed of 15 F3 families grown at two locations in 2 years. The family variance component estimate was highly significant (p≤0.01). Estimates of the variance components for the family × year and family × location interactions were nonsignificant. The estimated variance component for the family × year × location interaction was significant (p≤.05), although approximately one‐fourth the magnitude of the family and within‐plot variance components. Broad sense estimates of heritability for protein content calculated on a single plant, plot, and entry‐mean basis were 0.45, 0.58, and 0.90, respectively.The second study was composed of 100 F3 families conducted at two locations during a single growing season. Highly significant (p≤0.01) differences among the families were observed. Despite a highly significant (p≤0.01) correlation for protein content between locations, a few families with high protein content at one location had much lower protein content at the other location.Progress from selection among the families from these four crosses for protein content should be possible. Although the lower 50% of the families could be safely discarded on the basis of data from one location, selection among the higher protein genotypes should involve at least two environments.