Characterization of rye landraces with superior grain traits suitable for the Qinghai-Tibet Plateau

Abstract The Qinghai-Tibet Plateau faces a critical shortage of superior forage germplasm resources, and existing dual-purpose varieties require substantial improvements in both yield and quality. In this study, we conducted cluster analysis and comprehensive evaluation of 12 important agronomic and quality traits from 189 globally sourced rye (Secale cereale L.) landraces over a three-year field experiment. Our objective was to identify rye landraces with preferable traits for pre-breeding and to provide foundational materials for broadening the genetic basis of forage varieties and breeding high-yield, superior-quality crops adapted to the Qinghai-Tibet Plateau. The genetically diverse rye accessions exhibited abundant phenotypic variation in grain traits, offering rich and excellent parental materials for superior germplasm identification. Accessions with outstanding single or comprehensive traits were successfully screened: those with high thousand-kernel weight, elevated grain protein content, or combined high yield and superior quality can serve as key parental or basic materials for rye breeding programs. The three accessions with the highest comprehensive evaluation scores should be prioritized as core materials for breeding. In the cluster analysis of grain traits, clusters II and III emerged as optimal selection regions for high-yield and quality materials. The high-quality germplasm and key clusters identified in this study provide specific resource support for forage genetic improvement and sustainable development of grassland animal husbandry on the Qinghai-Tibet Plateau, addressing the gap in systematic screening of rye landraces with preferable traits.