Quantification of Specific Gene Interaction Effects between Populations Utilizing Diallel Information1

Publisher Website
Google Scholar
Abstract
Specific gene interactions associated with crosses are usable in corn (Zea mays L.) breeding programs. Analyses developed to quantify these gene interactions utilized diallel information among populations. A spatial relationship was developed where one axis resolved additive gene effects and additional axes as needed resolved dominance‐associated gene interaction effects. A diversity analysis weighed differences in gametic frequencies by nonadditive interaction effects found among populations, while a complementation analysis emphasized interactions effects found between groups of populations. Techniques for pooling information from different sources and for reducing dimensions were discussed. Least‐square estimates for coordinates, which permitted presentation in reduced dimensions, were developed. These analyses should be useful for evaluating the complementation of local breeding material by introduced germplasm and the changes in populations resulting from long‐term selection programs. The complementation of two North Carolina maize, Zea mays (L.), varieties (cultivars) by a Mexican race, ‘Tuxpeño’, was investigated where genes for adaptation were introduced from these two local varieties. Major favorable gene complementation of these local germplasms by genes introduced from Tuxpeño was found and was a consistent feature for two environments. Tuxpeño was sufficiently diverse from these two North Carolina varieties so that integration with these local varieties to obtain a gene pool for adaptation left considerable residual diversity. Replicate selections diverged for genes affecting both additive and dominance associated effects even though populations of 40 plants were intermated for each cycle of selection.