Identification of candidate genes that contribute to resistance towards F. graminearum in soybean PI 567301B
C. GEDLING (1), S. Verhoff (1), S. Lee (2), R. Mian (3), L. McHale (1), A. Dorrance (1) (1) The Ohio State University, U.S.A.; (2) North Carolina State University, U.S.A.; (3) USDA ARS, U.S.A.

Fusarium graminearum is primarily a fungal pathogen of wheat and related cereal crops, but can also infect soybean. Currently, fungicide seed treatments are used to manage this pathogen.  Host plant resistance is often the best management strategy for field crops. Thus, our overall objective is to identify and characterize sources of resistance that are effective towards seed, seedling, and root rots caused by F. graminearum in soybean. Using QTL mapping in an F7:10 recombinant inbred line (RIL) population derived from a cross between Wyandot (susceptible) and PI 567301B (resistance), two regions of the soybean genome were identified, with one QTL mapping to chromosome 8 contributing 38.5% of the phenotypic variation. Annotation of this region in the Williams 82 reference genome indicated that there are 38 genes, this region also includes the rhg4 locus for soybean cyst nematode (SCN). Based on previous screens, PI 567301B is susceptible to SCN. SNP analysis identified early stop codons in 5 genes, however, mRNA expression was detected with qRT-PCR. To narrow the region, 22 RILs with putative double recombinants were selected and additional KASPar markers designed for each gene in the region were used. Three putative candidate genes were identified based on the KASPar markers, two of those correspond with the genes with early stop codons. Three additional putative candidate genes were identified which are chalcone and stilbene synthase and are highly upregulated in inoculated PI567301B compared to inoculated Wyandot. Future functional genomics approaches using VIGS will be used to knock down expression of candidate genes to better assess their contribution to F. graminearum resistance.

Abstract Number: P16-448
Session Type: Poster