Heritability, Heterosis, and Maternal Effects of Alpha‐Amylase Activity in Barley

Abstract

Alpha‐amylase activity is an important quality factor in malting barley (Hordeum vulgare L.), yet its inheritance is not well understood. Research was undertaken to determine the inheritance and to examine maternal and heterotic effects of α‐amylase activity. The F1 and F2 seeds from reciprocal crosses among barley cultivars grown in the greenhouse were evaluated for α‐amylase activity. Heritability of α‐amylase activity was estimated by measuring activities of seed from field growouts of parents and progeny. The Ceralpha α‐amylase assay method, coupled with a modified malting procedure, was used to determine α‐amylase activity levels of all seed samples in this study. Alpha‐amylase activities of F1 seeds from reciprocal crosses were significantly different in two of three crosses. Activities of F2 seeds from reciprocal crosses did not differ, indicating that the reciprocal differences in the F1 were not cytoplasmicin origin but probably due to gene dosage. Average heterosis of α‐amylase activity of the F1's was 85% over the midparent and 47% over the high parent. In the F2 generation, average percent heterosis over the midparent was 35%. Heritability of α‐amylase activity on an F2 plant basis ranged from 0.37 to 0.65, while on an F5 line basis it ranged from 0.39 to 0.74. Average gain from selection for α‐amylase activity in the F2 and F5 generations was 5.4 and 9.1 Ug −1, respectively. Results indicate that selection for α‐amylase activity in populations of medium to wide genetic diversity should be successful in both early and advanced generations.