Authors: Q Li X M Chen M N Wang J X Jing
Publish Date: 2010/09/14
Volume: 122, Issue: 1, Pages: 189-197
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 allstage 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 genes PI 181434 was crossed with susceptible genotype ‘Avocet Susceptible’ Adult plants of 103 F2 progeny were tested in the field under the natural infection of P striiformis f sp tritici Seedlings of the parents F2 and F3 were tested with races PST100 and PST127 of the pathogen under controlled greenhouse conditions The genetic study showed that PI 181434 has a single dominant gene conferring allstage 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 F2 plants and their derived F3 lines tested in the greenhouse Amplification of the complete set of nullitetrasomic 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 733 and 822 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 resistanceThis research was supported by the US Department of Agriculture Agricultural Research Service Project No 53482200001400D Washington Wheat Commission Project No 13C30613923 and Vogel Foundation Project No 13Z30613824 PPNS No 0536 Department of Plant Pathology College of Agricultural Human and Natural Resource Sciences Agricultural Research Center Project Number WNP00823 Washington State University Pullman WA 991646430 USA The scholarship from China Scholarship Council to Q Li is appreciated The research is also part of the Northwest AF University Plant Pathology “111” Project B07049 We thank Dr RA McIntosh and Dr A Carter for critical reviews of the manuscript
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