Molecular Mapping of Stripe Rust Resistance Gene Yr76 in Winter Club Wheat Cultivar Tyee

Abstract

Tyee, one of the wheat cultivars used to differentiate races of Puccinia striiformis f. sp. tritici in the United States, was identified to have a single gene for all-stage resistance, tentatively named YrTye. To map the gene, Tyee was crossed with ‘Avocet Susceptible’ (AvS). Genetic analysis of the F1, F2, F2:3, and BC1 progenies confirmed a single dominant gene for resistance to race PSTv-37 that is avirulent to YrTye. A mapping population of 135 F2 plants was phenotyped with PSTv-37 and the derived F2:3 lines were tested with races PSTv-37, PSTv-40, and PSTv-79. The F2 mapping population was genotyped with simple sequence repeat (SSR) markers. A genetic map comprising 13 SSR markers located YrTye in chromosome 3AS flanked distally by SSR marker wmc11 and proximally by wmc532 at 2.6 and 3.4 cM, respectively. Amplification of Chinese Spring 3A deletion lines placed the gene in the distal bin 3AS4-0.45 to 1.00. Because YrTye is different from all formally named Yr genes in chromosomal location, we permanently name the gene Yr76. A near-isogenic line of spring common wheat was developed and selected by testing F3 lines derived from a AvS*4/Tyee cross with Tyee-avirulent and virulent races and the flanking markers. The specific SSR alleles flanking Yr76 were validated using cultivars and breeding lines with and without the gene, and showed high polymorphisms. The specificity of Yr76 is useful in differentiating P. striiformis f. sp. tritici races, and its tightly linked markers will be useful in developing resistant cultivars when combining the gene with other genes for resistance to stripe rust.

Molecular identification and mapping of a novel stripe rust resistance gene in wheat resistance line CH5389

“…b The wheat parents of CH5389. The stripe rust resistance gene Yr76 has been mapped on the short arm of chromosome 3A (XIANG et al 2016). In our study, YrCH5389 was located in the 3AL chromosome.…”

“…The first epidemic of wheat stripe rust occurred in China in the 1950s. Subsequently, five pandemics occurred in 1964, 1990, 2002, 2003, and 2009, resulting in yield losses of 3.2 billion, 1.8 billion, 1.3 billion, 980 million, and 810 million kilograms, respectively (XIANG et al 2016). Among the strategies for the control of wheat stripe rust, the most effective, economic, and environmentfriendly measure is the utilization and deployment of resistant varieties.…”

“…So far, more than 60 formally named stripe rust resistance genes (Yr1-Yr78) and many temporarily designated have been reported in wheat and its wild relatives (XIANG et al 2016;DONG et al 2017). However, with the rapid evolution and spread of virulence of stripe rust pathogen populations, the major resistance genes are only effective for a limited period of time.…”

“…There was high collinearity between the genomes of wheat, rice, Brachypodium distachyon, and sorghum (DRAPER et al 2001;PATERSON et al 2009). Based on comparative genomics, Expressed sequence tag (EST)-SSR markers are an effective approach for producing molecular marker linkage maps of target genes (LI et al 2006;LILLEMO et al 2008;LIU et al 2013;XIANG et al 2016). Using EST-SSR markers analysis, genetic linkage maps of stripe rust gene Yr26 and powdery mildew resistance gene Pm41 were located in wheat chromosome deletion 1BL bin 0.32-0.47 and 3BL bin 0.63-1.00, respectively (ZHANG et al 2013;WANG et al 2014).…”

Identification of Seedling Resistance Genes to Stripe Rust and Analysis of Adult Plant Resistance in 82 Wheat Cultivars from Gansu Province in China

“…Studies on the genetic characteristics and genes in wheat cultivars provide basic information for wheat breeding and growing. At least 76 Yr genes that confer resistance to stripe rust have been identified, some of which have been incorporated into commercial wheat cultivars (Xiang et al, 2016). Many of these genes are race-specific genes, showing hypersensitive reactions, and breeders are currently using several genes to develop new cultivars.…”