| Classification of crop genetic diversity is crucial to efficiently exploit the variation of alleles toward the genetic improvement of the crop. Maize quality traits are the focus of this study because of the use and added value of maize for an increasing variety of end-use products. The objective of this research was to study the genetic relationships among improved populations based on their grain quality. Ten populations, their respective crosses, and a group of checks were evaluated in an 8 x 8 partially balanced lattice design across eight environments. Estimates of general and specific combining abilities (GCA and SCA, respectively) were obtained using the analysis of Gardner and Eberhart model III. Clustering analysis was performed to see if groups of genetic diversity could be recognized. Combined analyses of variance showed differences among the genotypes for all traits studied. However, only percentage of root lodging showed significant average heterosis. No significant differences were found for protein content among the 10 parents. In general, narrow ranges were observed for the traits analyzed, particularly for the quality traits. GCA effects were more important than SCA for most traits, except for protein and starch content. Clustering analysis showed the presence of five diversity groups related by their origin (breeding program). This information is useful for assisting the current NDSU breeding efforts toward the genetic improvement of grain-quality traits. |
