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United States Department of Agriculture

Agricultural Research Service

Research Project: BREEDING FOR FHB RESISTANCE IN THE SOUTHEASTERN U.S. - UNIFORM NURSERY AND MARKER CHARACTERIZATION Project Number: 0500-00053-003-21
Project Type: Grant

Start Date: Jun 16, 2009
End Date: Jun 15, 2014

Objective:
Project Title 1 - Enhancement of Fusarium Head Blight Resistance in the Southeastern U.S. Germplasm Pool: The goal of this research is parental germplasm adapted to the southeastern U.S. with unique resistance to FHB. Project Title 2 - Marker Characterization of Soft Winter Wheat Scab Screening Nurseries: The specific objectives of this proposal are (1) to characterize entries in the Southern (SUWWSN) and Northern (NUWWSN and PNUWWSN) scab screening nurseries with markers linked to FHB QTL (VDHR goal 3); (2) to investigate association analysis as a means of identifying QTL associated with resistance (VDHR goal 4); and (3) to provide haplotype and marker polymorphism data on parents of mapping populations (VDHR goal 4).

Approach:
Project Title 1 - During the 2008-10 seasons the North Carolina program will contain F1, BC1 and BC2, three- and four-way breeding populations segregating for FHB resistance in the F1 to F12 generations. The pedigrees of the populations will contain many different exotic and adapted parents exhibiting partial to high levels of FHB resistance, and numerous superior soft red winter wheat cultivars and breeding lines used as sources of disease, insect, yield and end-use quality alleles. Our approach is enrichment of targeted populations of three-way F1’s, and F2 bulks using marker assisted selection combined with extensive phenotypic evaluation in later generations when heritabilities are greater and more seed is available. Our one-acre field mist irrigation system is capable of including 60 head row trays. Approximately 27 trays will be required for the Uniform Southern FHB Nursery, Preliminary, Advanced, and NC-Official Variety Trials. The remaining 33 trays will accommodate selected F3:4, and F4:5, populations. Sixty BC2F2:3 lines selected for the presence / absence of Qfhs.ndsu-3AS in an NC-Neuse background using the SSR marker Xgwm2 will undergo field and greenhouse testing for components of FHB resistance starting fall, 2008. BC2F2:3 lines selected for the presence of Frontana marker alleles at loci on 3A will undergo field testing for Type 1 resistance beginning fall 2008. A geographically diverse array of 15 accessions that do not contain Fhb1 served as donor parents in a pre-breeding program. Project Title 2 - This proposal focuses on providing information about mapped sources of FHB resistance (native and exotic) in soft winter wheat backgrounds by providing in-depth marker analysis of collaborative FHB screening nurseries. The uniform regional scab screening nurseries have been used by breeders to obtain multi-location data on reaction of soft wheat lines grown in FHB inoculated nurseries. While these data have been used to make decisions for advancement and for use as parents, little information has been available about the genetic basis of resistance. We are proposing to participate in a coordinated regional effort to better characterize FHB resistant eastern soft wheat germplasm utilizing molecular markers. By combining the abundant phenotypic data collected on the nurseries at multiple locations each year with molecular markers data, we will pursue an association mapping (AM) approach for resistance QTL identification. In this manner, new QTL or new alleles at previously identified QTL may be identified. We are also participating in coordinated mapping efforts by haplotyping parents with markers linked to previously mapped FHB resistance genes and conducting genome wide polymorphism screening.

Last Modified: 9/1/2014
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