The determinants and genome locations influencing grain weight and size in barley (Hordeum vulgare L.)

Grain weight and size are traits important to malting and feed barley. Understanding the determinants of grain weight and size, especially under stressful growing environments, will aid breeding efforts to improve these traits. The determinants of grain weight and size are discussed in relation to the pre- and post-anthesis periods of barley development. Genetic mapping of the loci influencing grain weight and size has provided a fundamental understanding of these traits, and a summary of mapped quantitative trait loci (QTLs) from Australian and international mapping populations is presented. The influence of developmental loci on grain weight and size QTLs, approaches to discovering non-developmentally related loci, and prospects for a marker assisted selection approach to improving grain weight and size are discussed.