Start Date: Jun 08, 2009
End Date: Jun 07, 2014
Project Title 1 - F1 populations are vernalized in summer, grown in a greenhouse August – October, and F2 populations are seeded at Evansville, IN about November 1. We make 400+ crosses annually. Essentially all of our current early-generation populations have one or multiple QTL for FHB resistance. Our parent lines that have these QTLs (with published markers) and Ernie, Bess and Truman, without markers, so we backcross one or more cycles to Ernie, Truman, and Bess, and simply phenotype for resistance plus genotype for QTL from the above parental donors. Several diseases, including FHB, are significant most seasons at Evansville, so effective selection in F2. We also submit grain samples for DON analysis. At Lafayette we grow plots of the NUWWSN and PNUWWSN, and all entries in regional performance nurseries, many of the commercial varieties in Indiana, and all entries in our IN multilocation yield nursery and preliminary yield nursery are seeded in disced corn residue and misted at 7-10am and 5-8pm on non-rainy days from 3 weeks prior to heading to 2 weeks after heading. For point inoculation: we inoculate a basal floret of the third spikelet from the tip of the spike with 500 F. graminearum macro spores in 10 ul dH2O with a dispensable syringe, then cover the spike with a clear plastic bag for 3 d, and at 21 – 24 dai (depending on weather conditions and disease development in a given season) determine the number of infected spikelets from the point of inoculation toward the base of the spike. By covering the spikes for 3 d, we have noted no or little natural infection to confound disease readings. Prebreeding/genetic analysis of novel FHB resistance: we are backcrossing the QTL Qfhs.pur-7EL into adapted soft winter wheat lines, and we are field testing a number of these lines in 2009. We will phenotype different combinations of FHB resistance QTL - we have developed by backcrossing and marker genotyping, combinations of multiple FHB resistance QTL. In the greenhouse, spring 2009, we are genotyping and point inoculating F4 families from BC1-3-derived plants that were grown in the field in 2008 and genotyped with markers and phenotyped by point inoculation and natural infection. We are repeating tests documenting that Qfhs.pur-7EL augments resistance of other resistance QTL/genes. And when Qfhs.pur-7EL and Fhb1 are combined the disease essentially does not spread to other spikelets after point inoculation, in tests in the greenhouse and field. Project Title 2 - We will phenotype, for a second season in 2009, a RI population of 250 lines from the cross: Truman/Mo 940317 (A coordinated project with MO, KY, and OH). We will grow two replications of the population and parent lines, with the two parents repeated in each replication. Plots are 1 meter long, 30 cm apart and consist of 80 seeds. At 21 – 25 days after flowering we will determine the percentage of spikes infected with F. graminearum, and we will determine the percentage of spikelets diseased in a random sample of 10 infected spikes per plot.