Genetic Relationships Among Hard Red Winter Wheat Cultivars as Evaluated by Pedigree Analysis and Gliadin Polyacrylamide Gel Electrophoretic Patterns¹

Abstract

Genetic relationships for all 903 pairwise combinations of 43 hard red winter wheat cultivars were evaluated using two indices: coefficient of parentage ( r ), computed from pedigree analysis, and a similarity coefficient ( s ), based on gliadin polyacrylamide gel electrophoresis (PAGE) patterns. Each index may vary from 0 for two unrelated cultivars to 1 for two identical cultivars. Mean r and s over all cultivars were 0.24 and 0.55, respectively. Cluster analyses based on the r and s matrices revealed dissimilar patterns of relationship in the hard red winter wheat gene pool. When cultivars were separated into two clusters based on the r matrix, mean r within and between clusters was 0.29 and 0.17, respectively. Separation of cultivars into two clusters based on s gave a mean s within and between clusters of 0.60 and 0.49, respectively. The rank correlation coefficient between r and s for all pairs of cultivars was 0.27 (significant at 0.01). Genetic drift and selection probably reduced the correlation between r and s . There was no relationship between ancestor‐cultivar r and s values because of the heterogeneous nature of the ancestors. Efficiency of breeding programs could be improved by computing r values and emphasizing crosses between diverse parents.