Dissertation
DEVELOPMENT AND USE OF cDNA-DERIVED SSR MARKERS FOR STUDYING PUCCINIA STRIIFORMIS POPULATIONS AND MOLECULAR MAPPING OF NEW GENES FOR EFFECTIVE RESISTANCE TO STRIPE RUST IN DURUM WHEAT
Doctor of Philosophy (PhD), Washington State University
01/2012
Handle:
https://hdl.handle.net/2376/4297
Abstract
<italic>Puccinia striiformis<italic>, a basidiomycete fungus, produces dikaryotic urediniospores causing stripe rust of wheat, barley, and many grass species. To study its population biology, three cDNA libraries were screened for simple sequence repeats (SSRs) and their flanking sequences were used to design primers. Seventeen primer pairs produced stable polymorphic markers among 28 isolates of the pathogen.
To characterize stripe rust on grasses and determine if somatic hybridization occur between <italic>Pst<italic> and <italic>Psh<italic>, 103 isolates from wheat, barley, and various grasses were tested on 20 wheat and 12 barley genotypes that are used to differentiate races of <italic>Pst<italic> and <italic>Psh<italic>, respectively. Virulence analyses indicated that grass isolates were able to attack both wheat and barley genotypes. Molecular testing with 20 SSR markers showed that these isolates are hybrids between <italic>Pst<italic> and <italic>Psh<italic>. The results suggested that somatic hybridization occurs between Pst and Psh on grasses.
To determine how the <italic>Pst<italic> population reproduces in the US Pacific Northwest (PNW), a systemic collection of single-stripe samples were made in 2010 in 26 wheat fields in the PNW especially the Palouse region, where plants of <italic>Berberis vulgaris<italic>, an alternate host of <italic>Pst<italic>, still grow. Twenty one races and 66 molecular haplotypes were identified. The SSR marker data revealed two genetic groups: homokaryotic (most PNW isolates) and heterokaryotic (most non-PNW US isolates). The different karyotypes were related to the groups of races. The analysis of multi-locus association ruled out the possibility of sexual reproduction in the PNW population.
Because growing resistant cultivars is the most effective approach to control stripe rust and new genes are needed in breeding programs, studies were conducted to identify and map new genes for effective resistance. Two mapping populations were developed by crossing durum wheat genotypes PI 331260 and PI 480016 with susceptible common wheat Avocet Susceptible (AvS). A single dominant resistance gene was identified in each of the mapping populations. Using wheat SSR markers, both genes were mapped to wheat chromosome 1BS, but at different loci. Common wheat lines with these genes were selected for breeding programs to develop stripe rust resistant cultivars.
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Details
- Title
- DEVELOPMENT AND USE OF cDNA-DERIVED SSR MARKERS FOR STUDYING PUCCINIA STRIIFORMIS POPULATIONS AND MOLECULAR MAPPING OF NEW GENES FOR EFFECTIVE RESISTANCE TO STRIPE RUST IN DURUM WHEAT
- Creators
- Peng Cheng
- Contributors
- Xianming Chen (Advisor)Scot Hulbert (Committee Member)Tobin Peever (Committee Member)Kulvinder Gill (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Plant Pathology, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 181
- Identifiers
- 99900581452601842
- Language
- English
- Resource Type
- Dissertation