Exome Sequencing from Bulked Segregant Analysis Identifies a Gene for All-Stage Resistance to Stripe Rust on Chromosome 1AL in Chinese Wheat Landrace 'Xiaohemai'.

Stripe rust caused by f. sp. is one of the most destructive diseases of wheat. Identifying novel resistance genes applicable for developing disease-resistant cultivars is important for the sustainable control of wheat stripe rust. Chinese wheat landrace 'Xiaohemai' ('XHM') is an elite germplasm line with all-stage resistance (ASR) effective against predominant Chinese f. sp. races. In this study, we performed a bulked segregant analysis coupled with exome capture sequencing (BSE-seq) to identify a candidate genomic region strongly associated with stripe rust resistance on chromosome 1AL in 173 lines derived from the cross 'XHM' × 'Avocet S'. The gene, designated as , was validated by a conventional quantitative trait locus analysis using newly developed Kompetitive allele-specific PCR (KASP) markers, explaining up to 48.50% of the phenotypic variance. By testing a secondary mapping population comprising 144 lines from the same cross at the seedling stage with prevalent f. sp. race CYR34, was identified as a single Mendelian factor in a 1.5-cM interval flanked by KASP markers and . This region corresponded to a 5.76-Mb genomic interval on 'Chinese Spring' chromosome 1AL. Furthermore, two cosegregating KASP markers showed high polymorphisms among 130 Chinese wheat cultivars and could be used for marker-assisted selection. Because no other genes for ASR that originated from common wheat have been detected on chromosome 1AL, is likely a novel gene that can be incorporated into modern breeding materials to develop wheat cultivars with enhanced stripe rust resistance.