Study of Grain Size in a Recombinant Inbred Line Population Derived from Yunpi 2 × Large-Grained Barley

Abstract

This study utilized two parental lines, "Yunpi 2," a locally selected variety from Yunnan with notable differences in functional component content, and a large-grained barley variety with characteristic hooked awns, to construct an F5 generation recombinant inbred line (RIL) population ("Yunpi 2 × Large-Grained Barley"). Precise measurements of grain length, width, and thickness were conducted on 169 materials, including the two parental lines and 167 RILs, followed by genetic analysis. The objective was to select germplasm resources with superior grain traits, providing crucial materials for barley breeding and gene cloning. The results indicated significant differences in grain length between the two parental lines (difference value > 1), with most offspring grain lengths falling between the parental values but averaging lower than the parental mean. In contrast, differences in grain width and thickness were relatively small (difference value < 0.5), with the majority of offspring exhibiting widths and thicknesses greater than or equal to the larger parental value and averaging higher than the parental mean. This study demonstrates that grain size in barley RILs is closely related to parental grain size, with genetic traits significantly influenced by parental characteristics, providing important theoretical and practical guidance for barley variety improvement and genetic breeding.