Molecular Mapping of a Novel QTL Conferring Adult Plant Resistance to Stripe Rust in Chinese Wheat Landrace ‘Guangtoumai’

https://apsjournals.apsnet.org/doi/10.1094/PDIS-07-20-1544-RE

Yu Wu,Yuqi Wang,Fangjie Yao,Li Long,Jing Li,Hao Li,Zhien Pu,Wei Li,Qian-Tao Jiang,Jirui Wang,Yu-Ming Wei,Jian Ma,

Huoyang Kang,Pengfei Qi,Shoufen Dai,Mei Deng,You-Liang Zheng,Yunfeng Jiang and Guo-Yue Chen

Abstract

Stripe rust (yellow rust), caused byPuccinia striiformisf. sp.tritici(Pst), is one of the most destructive diseases of wheat in the world. Chinese wheat landrace ‘Guangtoumai’ (GTM) exhibited a high-level resistance against predominantPstraces in China at the adult-plant stage. The objective of this research was to identify and map the major locus/loci for stripe rust resistance in GTM. A set of 212 recombinant inbred lines (RILs) was developed from a cross between GTM and Avocet S (AvS). The parents and RILs were evaluated in three field tests (2018, 2019, and 2020 at Chongzhou, Sichuan) with the currently predominantPstraces for final disease severity (FDS) and genotyped with the Wheat 55K SNP array to construct a genetic map with 1,031 SNP markers. A major locus, namedQYr.GTM-5DL, was detected on chromosome 5DL in GTM. The locus was mapped in a 2.75 cM interval flanked by SNP markersAX-109855976andAX-109453419, explaining up to 44.4% of the total phenotypic variation. Since no knownYrgenes have been reported on chromosome 5DL,QYr.GTM-5DLis very likely a novel adult plant resistance (APR) locus. Haplotype analysis revealed that the resistance allele displayed enhanced levels of stripe rust resistance and is likely present in 5.3% of the 247 surveyed Chinese wheat landraces. The derived cleaved amplified polymorphic sequence (dCAPS) markerdCAPS-5722, converted from a SNP marker tightly linked toQYr.GTM-5DLwith 0.3 cM, was validated on a subset of RILs and 48 commercial wheat cultivars developed in Sichuan. The results indicated thatQYr.GTM-5DLwith its linked dCAPS marker could be used in marker-assisted selection to improve stripe rust resistance in breeding programs, and this QTL will provide new and possibly durable resistance to stripe rust.