Functional characterization and identification of superior haplotypes of barley HvGL7-2H (Hordeum vulgare L.) in grain features

Barley (Hordeum vulgare L.) is the fourth largest cereal crop all over the world in terms of planting area. Kernel traits, such as grain length, grain width, and thousand grain weight, are crucial for barley yield and quality. Cloning kernel traits related genes and identifying superior alleles for them are essential for marker-assisted selection in barley breeding. In the present study, HvGL7-2H was cloned from barley according to the known rice GL7 gene. Functional validation of HvGL7-2H based on the EMS mutants of barley landrace "Hatiexi" proved that it played an important role in grain length. Using a panel consisting of 363 barley accessions, candidate gene-based association analysis was explored to identify superior haplotypes for HvGL7-2H. The results showed that Hap3 was the superior haplotype for both grain length and thousand grain weight, and Hap4 was also the superior haplotype for thousand grain weight. In conclusion, the genotypes carrying the superior allele are important gene donators, and the molecular markers identified in this study will be helpful for grain size and yield improvement in barley breeding.