Author
CHENG, PENG - Washington State University | |
XU, LIANGSHENG - Washington State University | |
WANG, MEINAN - Washington State University | |
See, Deven | |
Chen, Xianming |
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/7/2014 Publication Date: 8/21/2014 Citation: Cheng, P., Xu, L., Wang, M., See, D.R., Chen, X. 2014. Molecular mapping of genes Yr64 and Yr65 for stripe rust resistance in hexaploid derivatives of durum wheat accessions PI 331260 and PI 480016. Theoretical and Applied Genetics. 127:2267–2277. Interpretive Summary: Stripe rust is one of the most important diseases of wheat worldwide and resistance is the best control strategy. Durum wheat accessions PI 331260 and PI 480016 were resistant to all tested races of the stripe rust pathogen. To transfer the resistance genes to common wheat and map them to wheat chromosomes, both accessions were crossed with the stripe rust susceptible spring wheat ‘Avocet S’. Resistant F3 plants with 42 chromosomes were selected cytologically and by rust phenotype. A single dominant gene for resistance was identified in segregating F4 lines from each cross. F6 populations for each cross were developed from single F5 plants and used for genetic mapping. Different genes from PI 331260 and PI 480016 were mapped to different loci in chromosome 1BS using molecular markers. The genes from these accessions are flanked by different molecular markers and located in different regions of the same chromsome. Chromosomal locations and allelism tests indicated that the two genes are different from each other, and reactions to various races of the pathogen showed that they are different from previously designated genes for stripe rust resistance. Therefore, we name the gene in PI 331260 as Yr64 and that in PI 480016 as Yr65. These genes and their flanking markers and selected common wheat lines should be valuable for diversifying resistance genes used in breeding wheat cultivars with stripe rust resistance. Technical Abstract: Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat worldwide and resistance is the best control strategy. Durum wheat accessions PI 331260 and PI 480016 were resistant to all tested Pst races. To transfer the resistance genes to common wheat and map them to wheat chromosomes both accessions were crossed with the stripe rust susceptible spring wheat ‘Avocet S’ (AvS). Resistant F3 plants with 42 chromosomes were selected cytologically and by rust phenotype. A single dominant gene for resistance was identified in segregating F4 lines from each cross. F6 populations for each cross were developed from single F5 plants and used for genetic mapping. Different genes from PI 331260 and PI 480016 were mapped to different loci in chromosome 1BS using simple sequence repeat (SSR) markers. The gene from PI 331260 was flanked by Xgwm413 and Xgdm33 in bin 1BS9-0.84-1.06 at genetic distances of 3.5 cM and 2.0 cM; and the gene from PI 480016 was flanked by Xgwm18 and Xgwm11 in chromosome bin C-1BS10-0.50 at 1.2 cM and 2.1 cM, respectively. Chromosomal locations and allelism tests indicated that the two genes were different from each other, and reactions to various races of the pathogen showed that they were different from previously designated genes for stripe rust resistance. We named the gene in PI 331260 as Yr64 and that in PI 480016 as Yr65. These genes and their flanking markers and selected common wheat lines should be valuable for diversifying resistance genes used in breeding wheat cultivars with stripe rust resistance. |