Abstract
We analyzed the causes of the occurrence of cracked grains and the impact of hordoindoline genotypes on it in two-row barley. The rate of cracked grains, was correlated with the kernel hardness (r=−0.608**), and grain weight (r=0.588**). Therefore, we created a regression formula for the estimation of the rate of cracked grains by using kernel hardness and grain weight as the variables. Next, we confirmed that compared with the lineages of barley carrying the hordoindoline gene Hinb-2a, the lineages of the Hinb-2b had higher kernel hardness, required a longer time for parling the grains, and showed a lower rate of cracked grains, and a lower degree of whiteness. When the regression formula was applied to the progeny lineages, we were able to select lineages with low rates of cracked grains at a proportion of approximately 75% in the Hinb-2a genotype lineage group. Meanwhile, in the Hinb-2b genotype lineage group, we were able to select lineages with low rates of cracked grains at a proportion of approximately 70%, though their heritability and improving effect were low. To promote the barley breeding, it is useful to conduct a primary selection of Hinb-2a genotypes by using the regression formula and to select those with a low rate of cracked grains, or to select the Hinb-2b genotype with a shorter parling time and higher degree of whiteness.
