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United States Department of Agriculture

Agricultural Research Service

Research Project: CONTROL OF RUSTS OF CEREAL CROPS Title: Characterization and molecular mapping of Yr52 for high-temperature adult-plant resistance to stripe rust in spring wheat germplasm PI 183527

Authors
item Ren, Runsheng -
item Wang, Meinan -
item Chen, Xianming
item Zhang, Zhongjun -

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 19, 2012
Publication Date: May 5, 2012
Citation: Ren, R., Wang, M., Chen, X., Zhang, Z. 2012. Characterization and molecular mapping of Yr52 for high-temperature adult-plant resistance to stripe rust in spring wheat germplasm PI 183527. Theoretical and Applied Genetics. 125:847-857.

Interpretive Summary: Stripe rust is one of the most destructive diseases of wheat worldwide. Resistance is the best approach to control the disease. High-temperature adult-plant (HTAP) stripe rust resistance has proven to be race non-specific and durable. However, genes conferring high-levels of HTAP resistance are limited in number and new genes are urgently needed for breeding programs. Spring wheat germplasm PI 183527 showed a high-level of HTAP resistance against stripe rust in our germplasm evaluation over several years. To elucidate the genetic basis of resistance, we made a cross between PI 183527 and susceptible wheat genotype Avocet S. The results show that PI 183527 has a single dominant gene conferring HTAP resistance. A linkage map was constructed with 11 molecular markers, which mapped the gene to the distal region of chromosome 7BL. The polymorphism rates of the two tightly flanking markers in 74 wheat genotypes were 74% and 30%, respectively; and the two markers in combination could distinguish the resistance gene in 82% of tested genotypes. The gene is found to be at chromosomal region different from Yr39 in Alpowa which was previously mapped to chromosome 7BL, and also different from other genes in chromosomal location and type of resistance . The gene in PI 183527 was therefore designed as Yr52. This new gene and flanking markers should be useful in developing wheat cultivars with high-level and durable resistance to stripe rust.

Technical Abstract: Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive diseases of wheat worldwide. Resistance is the best approach to control the disease. High-temperature adult-plant (HTAP) stripe rust resistance has proven to be race non-specific and durable. However, genes conferring high-levels of HTAP resistance are limited in number and new genes are urgently needed for breeding programs to develop cultivars with durable high-level resistance to stripe rust. Spring wheat germplasm PI 183527 showed a high-level of HTAP resistance against stripe rust in our germplasm evaluation over several years. To elucidate the genetic basis of resistance, we made a cross between PI 183527 and susceptible wheat genotype Avocet S. Adult plants of parents, F1, F2 and F2:3 progeny were tested with selected races under the controlled greenhouse conditions and in fields under natural infection of the pathogen populations. PI 183527 has a single dominant gene conferring HTAP resistance. Resistance gene analog polymorphism (RGAP) and simple sequence repeat (SSR) markers in combination with bulked segregant analysis (BSA) were used to identify markers linked to the resistance gene. A linkage map consisting of 4 RGAP and 7 SSR markers was constructed for the resistance gene using data from 175 F2 plants and their derived F2:3 lines. Amplification of nulli-tetrasomic, ditelosomic and deletion lines of Chinese Spring with three RGAP markers mapped the gene to the distal region (0.86-1.0) of chromosome 7BL. The molecular map spanned a genetic distance of 27.3 cM and the resistance gene was narrowed to a 2.3 cM interval flanked by markers Xbarc182 and Xwgp5258. The polymorphism rates of the flanking markers in 74 wheat genotypes were 74% and 30%, respectively; and the two markers in combination could distinguish the alleles at the resistance locus in 82% of tested genotypes. To determine the genetic relationship between this resistance gene and Yr39, a gene also on 7BL conferring HTAP resistance in Alpowa, a cross was made between PI 183527 and Alpowa. F2 segregation indicated the genes were 36.5±6.75 cM apart. The gene in PI 183527 was therefore designed as Yr52. This new gene and flanking markers should be useful in developing wheat cultivars with high-level and durable resistance to stripe rust.

Last Modified: 12/22/2014
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