Inheritance of Traits Associated with Grain Yield in a Spring Oat Diallel

Abstract

Developing oat (Avena sativa L.) cultivars with superior grain yield potentials is difficult. Our objectives were to characterize traits associated with high grain yield of elite genotypes and to determine their inheritance and potential value for selection. Three extremely high yield (HY) genotypes (‘Ogle’, ‘Orbit’, and ‘Hazel’) and three moderate yield (MY) genotypes (‘Dal’, PA2250, PA12422) were crossed in diallel combinations. Data were collected on parents and F2 progenies in the field during 1985 and on parents and F3 lines in 1986. The HY genotypes were always superior for seed weight and usually superior or equal to the MY genotypes for tiller production, harvest index (HI), and biological yield. In the F2, HY progenies were always superior or equal to MY progenies for most traits measured. Additive genetic effects were most important for all traits, and except for tillers/plant, nonadditive effects also were significant. In the F3, large, significant additive genetic effects occurred for most traits. Nonadditive effects also were significant for seed weight, grain yield, biological yield, and HI, with an important specific combining‐ability component for the latter three. All significant correlation coefficients between traits of F2 plants and F3‐derived lines were small, and multiple regression models based on F2 traits were not useful for predicting F3 line yields. Since additive genetic effects for yield‐related traits were large, however, some progress should result from early generation selection for those traits.