Dissertation
MOLECULAR CHARACTERIZATION OF EFFECTIVE SOURCES OF STRIPE RUST RESISTANCE IN TETRAPLOID WHEAT
Doctor of Philosophy (PhD), Washington State University
01/2016
Handle:
https://hdl.handle.net/2376/116931
Abstract
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a globally devastating disease of wheat. New Pst races overcoming the currently resistant wheat varieties and more frequent stripe rust-favorable weather conditions threaten the global wheat crops. The most economically and environmentally friendly approach to control stripe rust is to grow highly resistant cultivars with durable resistance. However, development of varieties with high levels of durable resistance has been limited by the small number of well-characterized and effective resistance genes available and technical difficulties in pyramiding several resistance genes in one plant. In order to identify more resistance genes and provide more marker-trait association information for marker-assisted selection and wheat improvement, genome-wide association mapping was conducted in cultivated emmer wheat (Triticum turgidum ssp. dicoccum), elite durum wheat (Triticum turgidum ssp. durum) and Ethiopian durum wheat landrace populations using the wheat 90,000 Illumina iSelect single nucleotide polymorphism array. In emmer wheat population, we identified thirty-eight loci significantly associated (P<0.005) with seedling resistance and three loci associated with adult plant resistance (APR) in multiple environments. Thirty-five loci were putatively new since they were located within chromosome regions where no stripe rust resistance genes have been mapped. In an elite durum wheat population, five loci significantly associated with seedling response at FDR adjusted P<0.1 and twelve loci significantly associated with APR in at least two environments at marker-wise P<0.005 were detected. Three of these loci were potentially novel based on the relative map distance of previously reported stripe rust resistance genes. In an Ethiopian durum wheat landrace population, six seedling resistance loci effective against multiple races and eighteen APR loci detected in at least two environments had significant associations at marker-wise P<0.005, thirteen of which are likely new. At least one major seedling resistance gene, positioned from 35.7-39.9 cM on chromosome 1B, was identified in three tetraploid populations. Our results provide wheat breeders an overview of the genetic basis of stripe rust resistance in diverse tetraploid wheat populations and resistance loci effective to contemporary Pst races that could be incorporated into wheat breeding lines.
Metrics
34 File views/ downloads
20 Record Views
Details
- Title
- MOLECULAR CHARACTERIZATION OF EFFECTIVE SOURCES OF STRIPE RUST RESISTANCE IN TETRAPLOID WHEAT
- Creators
- Weizhen Liu
- Contributors
- Michael O Pumphrey (Advisor)Arron H Carter (Committee Member)Deven R See (Committee Member)Xianming Chen (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Crop and Soil Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 232
- Identifiers
- 99900581633701842
- Language
- English
- Resource Type
- Dissertation