Start Date: Apr 06, 2009
End Date: Apr 05, 2014
Project Title 1: To meet this overall goal, this breeding pre-proposal has four specific objectives: (1) screening: accurately characterizing resistance in existing cultivars, advanced breeding lines and populations by evaluating them under a range of disease pressures at two locations; (2) breeding: choosing parents, crossing them and selecting resistant progeny based on phenotype as well as genotype. Parents include sources of native quantitative resistance as well as Sumai-3 derived lines whose type II resistance can be tracked with DNA markers and then confirmed phenotypically; (3) collaboration: growing and screening collaborative nurseries to facilitate germplasm exchange, broaden the diversity of sources used in the breeding program, and provide excellent pre-release multi-location data for candidate varieties. We will also phenotype a set of recombinant inbred lines from a cross with 'Truman' a promising source of native resistance, thus accelerating the mapping of its resistance and putting markers associated with in the hands of breeders; and (4) outreach: Through collaboration with our grains extension specialist and extension plant pathologist, we will screen a set of varieties and elite breeding lines in scab nurseries at two KY locations with and without fungicides. The focus of the study will be to educate growers about the need to grow scab resistant varieties and the need to use fungicides when conditions warrant. Data will be posted on a website and will be presented at field days and grower meetings. Project Title 2: These lines will be evaluated for incidence of infection, percentage of Fusarium damaged kernels, and DON level. Specifically, incidence will be assessed on a random 20 head sample as the percentage of heads in the sample showing any FHB symptoms. Heads will then be assessed for severity as the mean percentage of diseased spikelets on the 20-head sample. Field scab index will be determined for each RIL as incidence x severity. Accurately characterizing the phenotype of the lines is essential if the resistance genes are to be mapped accurately. Phenotypic data from all locations will be compiled and analyzed with the genotypic data in MO. The hoped-for "deliverable" from this collaborative study will be DNA markers linked to the Truman resistance genes. The advantage of this collaborative approach is that the phenotypic data will be collected in less than half the time that would be required ifjust one program were doing the research. Breeders will then be able to use these markers to screen segregating populations and advance potentially resistant lines carrying the Truman resistance to the scab nursery.