Author
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LU, YAN - Washington State University |
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WANG, MEINAN - Washington State University |
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Chen, Xianming |
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See, Deven |
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Chao, Shiaoman |
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JING, JINXUE - Northwest Agriculture And Forestry University |
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/10/2014 Publication Date: 4/30/2014 Publication URL: http://www.springerlink.com/openurl.asp?genre=article&id=doi:10.1007/s00122-014-2312-0 Citation: Lu, Y., Wang, M., Chen, X., See, D.R., Chao, S., Jing, J. 2014. Mapping of Yr62 and a small effect QTL for high-temperature adult-plant resistance to stripe rust in spring wheat PI 192252. Theoretical and Applied Genetics. 127:1449-1459. Interpretive Summary: Stripe rust is a devastating disease of wheat worldwide. Spring wheat germplasm PI 192252 showed a high level of high-temperature adult-plant (HTAP) resistance to stripe rust in germplasm evaluation over eight years in the State of Washington. To elucidate the genetic basis of resistance, PI 192252 was crossed with ‘Avocet Susceptible’ (AvS). A mapping population of 150 recombinant inbred lines (RILs) was developed . Stripe rust tests were conducted with selected races of the pathogen in a greenhouse and in fields under natural infections. The relative area under the disease progress curve (rAUDPC) data measuring disease severity showed continuous distributions, indicating that HTAP resistance of PI 192252 was controlled by quantitative trait loci (QTL). Two QTL were identified in PI 192252, explaining 74.2% of the total phenotypic variation for rAUDPC. These two QTL were mapped to chromosomes 4BL and 5BS with simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers and explained 40-60% and 22-27%, respectively, of the phenotypic variation across the four environments. Because the major-effect QTL on 4BL is different from previously named Yr genes and inherited as a single gene, it is named Yr62. The SSR marker alleles Xgwm192 and Xgwm251 flanking Yr62 were different from the alleles in various wheat varieties, suggesting that these markers could be useful in marker-assisted selection for incorporating the new gene into commercial cultivars. Technical Abstract: Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease of wheat worldwide. Spring wheat germplasm PI 192252 showed a high level of high-temperature adult-plant (HTAP) resistance to stripe rust in germplasm evaluation over eight years in the State of Washington. To elucidate the genetic basis of resistance, PI 192252 was crossed with ‘Avocet Susceptible’ (AvS). A mapping population of 150 F5 recombinant inbred lines (RILs) was developed using single-seed descent. Stripe rust tests were conducted with selected Pst races in a greenhouse and in fields under natural infections. The relative area under the disease progress curve (rAUDPC) data showed continuous distributions, indicating that HTAP resistance of PI 192252 was controlled by quantitative trait loci (QTL). Two QTL were identified in PI 192252, explaining 74.2% of the total phenotypic variation for rAUDPC. These two QTL were mapped to chromosomes 4BL (QYrPI192252.wgp-4BL) and 5BS (QYrPI192252.wgp-5BS) with SSR and SNP markers and explained 40-60% and 22-27%, respectively, of the phenotypic variation across the four environments. Because the major-effect QTL on 4BL is different from previously named Yr genes and inherited as a single gene, it is named Yr62. The SSR marker alleles Xgwm192222 and Xgwm251133 flanking Yr62 were different from the alleles in various wheat varieties, suggesting that these markers could be useful in marker-assisted selection for incorporating the gene into commercial cultivars. |