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United States Department of Agriculture

Agricultural Research Service

Research Project: Develop High-Throughput Markers for Genetic Improvement of Wheat for Multiple Traits

Location: Hard Winter Wheat Genetics Research Unit

2013 Annual Report


1a.Objectives (from AD-416):
Develop and implement next generation molecular marker technology in wheat breeding.


1b.Approach (from AD-416):
Mapping populations will be analyzed using the 90K wheat SNP chip and SSR markers and detailed SNP/SSR maps will be constructed and used for mapping of important loci controlling disease resistance, abiotic stress tolerance, grain quality, etc. Low-throughput markers reported for different genes will be converted into a set of high throughput SNP markers by LD analysis of 90K SNP chip. Developed SNPs will be assembled into sets of 30-35 SNP markers to be analyzed in Sequenom MassArray and validated using different mapping populations. Those marker sets will be used for selection of multiple traits in breeding programs.


3.Progress Report:

Pre-harvest sprouting (PHS) of wheat causes an estimated $1 billion in annual losses worldwide. However, the mechanism of wheat resistance to PHS has not been characterized. We found that a MOTHER OF FLOWERING TIME-like gene (TaMFT) on chromosome 3A regulates PHS resistance in hard white winter wheat. Two nucleotide mutations in the coding region of the gene, resulting in a malfunctioning protein, change wheat cultivars from PHS-resistant to susceptible. A high-throughput DNA marker developed from the gene can be used for marker-assisted selection for PHS in new wheat breeding lines.

Stem rust is one of the most serious diseases of wheat worldwide. The discovery of new virulent stem rust races in the Ug99 race complex brings a new threat to global wheat production. Stacking several stem rust resistance (Sr) genes in one adapted variety is one strategy to develop durably resistant varieties. Stacking Sr genes is only feasible with accurate DNA markers tightly linked to Sr genes. In this study, DNA markers linked to resistance genes Sr2, Sr22, Sr26, Sr32, Sr35, Sr39, and Sr40, were evaluated for usefulness in marker-assisted breeding of hard winter wheat. Useful markers for all the genes were validated and are recommended for marker-assisted stacking of these genes to develop wheat cultivars with stem rust resistance against Ug99 races.


Last Modified: 9/22/2014
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