Yr45, a new wheat gene for stripe rust resistance on the long arm of chromosome 3D

Abstract

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive diseases of wheat worldwide. Growing resistant cultivars is the most effective approach to control the disease, but only a few genes confer effective all-stage resistance against the current populations of the pathogen worldwide. It is urgent to identify new genes for diversifying sources of resistance genes and for pyramiding genes for different types of resistance in order to achieve high levels of durable resistance for sustainable control of stripe rust. The common spring wheat genotype 'PI 181434', originally from Afghanistan, was resistant in all greenhouse and field tests in our previous studies. To identify the resistance gene(s) PI 181434 was crossed with susceptible genotype 'Avocet Susceptible'. Adult plants of 103 F(2) progeny were tested in the field under the natural infection of P. striiformis f. sp. tritici. Seedlings of the parents, F(2) and F(3) were tested with races PST-100 and PST-127 of the pathogen under controlled greenhouse conditions. The genetic study showed that PI 181434 has a single dominant gene conferring all-stage resistance. Resistance gene analog polymorphism (RGAP) and simple sequence repeat (SSR) techniques were used to identify molecular markers linked to the gene. A linkage map of 8 RGAP and 2 SSR markers was constructed for the gene using data from the 103 F(2) plants and their derived F(3) lines tested in the greenhouse. Amplification of the complete set of nulli-tetrasomic lines and selected ditelosomic lines of Chinese Spring with an RGAP marker and the two SSR markers mapped the gene on the long arm of chromosome 3D. Because it is the first gene for stripe rust resistance mapped on chromosome 3DL and different from all previously named Yr genes, the gene in PI 181434 was designated Yr45. Polymorphism rates of the two closest flanking markers, Xwgp115 and Xwgp118, in 45 wheat genotypes were 73.3 and 82.2%, respectively. Single nucleotide polymorphisms (SNPs) were identified in the eight wheat genotypes sharing both flanking markers. The RGAP markers and potential SNP markers should be useful in incorporating the gene into wheat cultivars and in pyramiding it with other genes for durable resistance.

Review Article: High-Temperature Adult-Plant Resistance, Key for Sustainable Control of Stripe Rust

“…The integrated approach allowed us having mapped numerous genes or QTL for HTAP resistance, as well as genes for all-stage resistance [47,58,[69][70][71][72][73][74][75][76]. Table 3 lists chromosomal locations and linked markers for genes or QTL conferring HTAP or HTAP-alike resistance (resistance can be detected in adult plants under high temperatures, such as temperature sensitive and slow-rusting) to stripe rust in wheat.…”

“…Markerassisted selection will be more useful for this approach. Markers for numerous HTAP resistance genes ( Table 3) and all-stage resistance [2,74,75] are available with various degrees of usefulness. In the US, many wheat breeding programs combining Yr5, Yr15, Yr26 and other genes for effective all-stage resistance with HTAP resistance genes such as Yr18, Yr29, Yr36, Yr39, and other QTL in Stephens, Eltan, Madsen, Jagger and Louise using and without using molecular markers.…”

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

“…As Yr76 is race-specific, it should not be used alone. Therefore, combinations of this gene with other widely effective all-stage resistance genes such as Yr5, Yr15, Yr45, Yr53, Yr61, Yr64, Yr65, and YrSP (Chen et al 2003;Feng et al 2015;Li et al 2010;Murphy et al 2009;Xu et al 2013;Zhou et al 2014a), and/or with genes for HTAP resistance such as Yr36, Yr39, Yr52, Yr59, Yr62, and many temporarily named QTL (Carter et al 2009;Chen 2013;Chen 2007, 2009;Lu et al 2014;Ren et al 2012;Uauy et al 2005;Zhou et al 2014b) are recommended.…”

Molecular tagging of a stripe rust resistance gene in Aegilops tauschii

“…Resistant cultivars are the most economical and environmentally friendly means to reduce damage caused by stripe rust. Worldwide, stripe rust resistance genes Yr1-Yr48 and many provisionally designated genes have been identified in wheat and its relatives (McIntosh et al 2008(McIntosh et al , 2010Marais et al 2009;Cheng and Chen 2010;HerreraFoessel et al 2010;Li et al 2010). Lines possessing genes Yr5, Yr10, Yr12, Yr13, Yr14, Yr15, Yr16, Yr18, Yr24/Yr26, Yr36, Yr39, Yr41, and some temporarily designated genes are still effective in China whereas at least some lines with Yr1, Yr2, Yr3, Yr4, Yr6, Yr7, Yr8, Yr9, Yr17, Yr20, Yr21, Yr22, Yr25, Yr27 and Yr29 are ineffective to currently prevalent races (Wan et al 2007;Kang et al 2010).…”