Determination of Optimum Gamma Ray Irradiation Doses for Hulless Barley (Hordeum vulgare var. nudum L. Hook. f.) Genotypes

Abstract

The limited germplasm resources of hulless barley restrict the breeding of hulless barley with improved traits. Mutation techniques are an effective tool for generating variation for plant breeding studies. This study aimed to evaluate the impact of gamma-ray at different doses on certain seedling properties of M1 plants of two hulless barley genotypes, as well as determine the effective dose (ED50). The seeds of two hulless two-row barley genotypes, cv. Yalin and hulless barley line YAA7050-14, were irradiated with 100, 150, 200, 250, and 300 gray Gamma-rays delivered by a Cobalt 60 source along with non-irradiated control samples. Gamma-ray irradiation affects the seedling properties of M1 plants of both hulless barley genotypes significantly. The significant effect varied based on the doses, traits, and genotypes. While lower doses were found statistically identical to the control in the majority of qualities in the M1 generation, 250-300 gray gamma ray doses caused statistically significant decreases in the majority of characteristics studied in both genotypes. The effective doses (ED50) for hulless barley genotypes were determined by plotting growth reduction values of seedling lengths, then the polynomial regression equations were calculated for each genotype. It was determined that 50% growth reduction in shoot length was reached at 214.1 Gy and 253.4 Gy for cv. Yalin and line YAA7050-14, respectively.