Sorghum (Sorghum bicolor (L.) Moench) is the fifth most widely grown crop in the world and provides food, feed, fuel and fiber in over a hundred countries. Sorghum is an ideal bioenergy crop for the southeastern United States due to its high biomass potential on poor soils with limited inputs. Expansion of sorghum in this region, however, is contingent on resistance to the aggressive fungal pathogen Colletotrichum sublineolum (Henn.), the causal agent of anthracnose that can reduce grain, sugar and biomass yield by as much as 70%. We have identified a major anthracnose resistance locus on chromosome 9 using a biparental mapping population derived from the inbred lines Bk7 (resistant) x Early Hegari-Sart (susceptible). The population was genotyped by sequencing and phenotyped in three environments. The locus is 1.2 Mb in size and contains 12 candidate resistance genes. The genetic proof that one or more of these genes are responsible for conferring resistance requires showing that inactivation of the gene in a resistant line results in a susceptible phenotype, or introducing the allele of the resistant parent in a susceptible line and demonstrating acquisition of resistance. As few sorghum lines are amenable to transformation, and genome editing is not yet feasible, the best alternative is virus-induced gene silencing (VIGS) of candidate resistance genes with the help of the tripartite Brome Mosaic Virus (BMV). We are in the process of cloning short fragments of cDNA in one of the viral sequences and will generate infectious RNA transcripts through in vitro transcription. Three-week old resistant sorghum seedlings will be inoculated with a mixture of transcripts. Two weeks post viral inoculation, the plants will be challenged with Colletotrichum conidia to assess the effect of different constructs on host-pathogen interaction. Elucidating the identity of the resistance gene(s) will facilitate the breeding of disease-resistant sorghums, and provide information on the mechanism of disease resistance. Supported by USDA-BRDI Award No. 2011-10006-30358 and US DOE award No. DE-SC0014439.