Identification of Anthracnose Resistance Loci in Sorghum Bicolor.

Colletotrichum sublineolum is an aggressive fungal pathogen that causes anthracnose in sorghum. The symptoms of anthracnose are leaf blight and stem rot. Sorghum bicolor, the fifth most grown cereal crop in the world, can be highly susceptible to the disease, most notably in environments that favor spread and infection of the fungus. Yield losses of up to 70% have been reported in susceptible germplasm. The sweet sorghum acreage in the Southeastern US is increasing steadily, spurred by growing interest in biofuel production and sorghum’s complimentary nature to Florida’s already established sugarcane industry. Resistance to anthracnose is, therefore, of paramount importance in the region’s hot and humid environment. We generated a biparental mapping population of 125 F4:5 sorghum lines to identify anthracnose resistance genes in the highly resistant cultivar Bk7. Two field trials have been performed in Florida and the population has been mapped using Genotyping by Sequencing. Preliminary QTL have been identified using QTL Cartographer. These data will be used to ultimately identify the molecular basis of disease resistance and to introgress this trait in susceptible germplasm with otherwise attractive agronomic properties. Supported by the Southeastern Sun Grant Center and USDA-NIFA Award No. 2010-38502-21854 and USDA-BRDI Award No. 2011-10006-30358.