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United States Department of Agriculture

Agricultural Research Service

Research Project: EVALUATION AND IMPROVEMENT OF CEREAL GERMPLASM FOR DISEASE RESISTANCE AND WINTER-HARDINESS Project Number: 6645-22000-016-00
Project Type: Appropriated

Start Date: Mar 28, 2008
End Date: Mar 27, 2013

Objective:
Objective 1: Identify sources of resistance to foliar fungal pathogens and introgress resistance into adapted wheat. Objective 2: Develop improved methods of marker-assisted selection and apply markers in development of improved wheat and oat. Objective 3: Characterize frequencies of virulence in pathogen populations to resistance sources in wheat germplasm and evaluate the risk potential of virulence transfer through gene flow. Objective 4: Characterize genetic factors conferring winter-hardiness in oat.

Approach:
Approach 1: Evaluation, identification, and incorporation of major gene resistance in wheat to powdery mildew and stripe rust using greenhouse, growth chamber and field facilities. Evaluation and identification of major gene resistance in progenitors of wheat to powdery mildew and stripe rust. Evaluation, identification, and incorporation of minor gene resistance in wheat to powdery mildew and stripe rust. Approach 2: Will apply marker-assisted selection to determine if we can rapidly introgress and pyramid new fungal resistance genes into soft winter wheat germplasm. Will apply marker technology to characterize the genetic factors for resistance by haplotyping, genetic linkage and QTL analyses. Phenotypic and marker analyses will be used to identify and develop germplasm having genes of interest for use in developing improved cultivars of small grains. Approach 3: Powdery mildew samples are obtained from collaborators in the U.S., U.K., and Middle East. Virulence frequencies are determined using powdery mildew resistance gene differentials on detached-leaf plates. In order to evaluate the extent of population subdivision, migration, and gene flow, nested cladistic analysis will be used because it may allow inferences about historical processes such as fragmentation and range expansion. Approach 4: Two oat cultivars differing in winter-hardiness that have been grown in the UOWHN for more than 40 years have been used to develop a mapping population for identification of genomic regions containing winter-hardiness genes. After cold acclimation, crowns will be prepared for freezing by trimming roots and leaves to approximately 3 cm. To identify markers suitable for high-throughput genotyping for this QTL and to identify new regions associated with winter-hardiness, SSR markers will be evaluated on the mapping population.

Last Modified: 12/22/2014
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