Thesis
Molecular mapping of a gene for resistance to stripe rust in spring wheat cultivar IDO377s and identification of a new race of Puccinia striiformis f. sp. tritici virulent on IDO377s
Washington State University
Master of Science (MS), Washington State University
2008
Handle:
https://hdl.handle.net/2376/100123
Abstract
Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most important diseases of wheat worldwide. The best strategy to control stripe rust is growing resistant cultivars. To study the genetics of the stripe rust resistance in 'IDO377s' spring wheat, a cross was made between IDO377s and 'Avocet Susceptible' (AVS). Parents, F2 plants, and F3 lines of the cross were tested with races PST-43 and PST-45 of P. striiformis f. sp. tritici in the seedling stage under controlled greenhouse conditions. The results of genetic analyses showed a single dominant gene in IDO377s for resistance to these races. The resistance gene analog polymorphism (RGAP) and simple sequence repeat (SSR) techniques were used to identify molecular markers linked to the resistance gene. A total of 10 markers were identified, of which the two closest flanked the locus by 5.5 and 4.4 cM. The pattern of presence and absence of two linked RGAP markers among the 21 nulli-tetrasomic lines of 'Chinese Spring' located the resistance gene to chromosome 2B. Testing ditelosomic line 2BL further refined the location of the gene to the long arm of chromosome 2B. The chromosomal location of the resistance gene was further confirmed by two 2BL- specific SSR markers and a sequence tagged site (STS) marker previously mapped to 2BL. Based on the chromosomal location and reactions to various races of the pathogen, the IDO377s gene, designated as YrIDO377s, is likely a novel gene different from all previously reported genes for resistance to stripe rust. A total of 108 wheat breeding lines and cultivars with IDO377s or related cultivars in their pedigree were used to validate the most closely linked flanking markers and select lines carrying YrIDO377s. The results showed that the flanking markers were reliable for assisting selection of breeding lines with the resistance gene. A new race, PST-127, was identified from an isolate collected from IDO377s in this study. How this new race would affect the use of YrIDO377s in breeding programs is discussed.
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Details
- Title
- Molecular mapping of a gene for resistance to stripe rust in spring wheat cultivar IDO377s and identification of a new race of Puccinia striiformis f. sp. tritici virulent on IDO377s
- Creators
- Peng Cheng
- Contributors
- Xianming Chen (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Plant Pathology, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525200601842
- Language
- English
- Resource Type
- Thesis