Variation in Kernel Growth Characters Among Soft Red Winter Wheats1

Abstract

One of the components of grain yield in wheat is kernel size. Kernel size is determined by rate and duration of kernel growth. Genetic variation and genotype ✕ environment interaction for these traits has not been assessed in a large sample of soft red winter wheats. In this study, variation in kernel growth characters was evaluated in 61 elite soft red winter wheat (Triticum aestivum L.) breeding lines and cultivars. Kernel growth rate (KGR) and effective filling period (EFP) were estimated from samples of 30 spikes in replicated plots at two locations in Kentucky. Significant genotypic variation for KGR and EFP was observed at both locations. Significant genotype ✕ environment interaction was also observed for these two traits. The KGR and EFP varied from 0.78 to 1.79 mg kernel ‒1 day ‒1 and 17.3 to 32.9 days respectively. Kernel size and grain yield were significantly correlated with KGR, while EFP was not significantly correlated with either character. The data suggest that date of physiological maturity may not always be correlated with date of anthesis. Early flowering genotypes with long EFP's reached physiological maturity later than genotypes which flowered later and had shorter EFP's. Selection for high KGR may be appropriate in developing early maturing wheat cultivars suitable for double cropping.