Identification and fine mapping of a novel leaf stripe resistance locus, QY-156, in the Tibetan hulless barley landrace Pengcuolinzongqingke

Leaf stripe disease, caused by the seed-borne fungal pathogen Pyrenophora graminea , poses a major threat to hulless barley production on the Qinghai–Tibet Plateau. In this study, a novel resistance locus, QY-156 , was identified in the Tibetan hulless barley landrace Pengcuolinzongqingke. Bulked segregant analysis coupled with whole-genome resequencing (BSA-WGRS), combined with KASP marker-based fine mapping and pangenome analysis, localized QY-156 to a 101-kb interval on chromosome 6H (533.393–533.494 Mb). Genetic analysis demonstrated that resistance is controlled by a single dominant gene. Expression analysis of candidate genes revealed that HORVU.MOREX.r3.6HG0622460.1 was strongly induced in the resistant genotype following P. graminea infection, whereas HORVU.MOREX.r3.6HG0622470.1 , encoding a GLR2.8-like protein, was significantly upregulated in the susceptible parent. Bioinformatic and structural analyses indicated that the protein encoded by HORVU.MOREX.r3.6HG0622470.1 is a glutamate receptor-like protein containing conserved PBP1_GABAb_receptor_plant, GluR_Plant, and Lig_chan domains, with predicted roles in signal transduction. These findings suggest that QY-156 represents a previously unreported resistance locus and that multiple genes within this interval may coordinately contribute to the regulation of stress responses. The tightly linked molecular markers and candidate genes identified in this study provide valuable resources for marker-assisted selection and map-based cloning of resistance genes in hulless barley.