Genome Mapping of Anthracnose Resistant Loci in Sorghum Germplasm

Sorghum (Sorghum bicolor) is an important grain crop and of growing importance for biofuels. However, its productivity may be limited by foliar diseases such as anthracnose caused by the fungus Colletotrichum sublineolum. Today, multiple sources of resistances have been identified but the lack of molecular characterization limited its use in breeding programs. Therefore, in this research we aim to genetic characterize the resistance response of two different sources; IS18760 (Sudan) and QL3 (India) using two sets of >100 recombinant inbred lines (RIL). In parallel, the resistant locus (Cs-SC112) present in SC112-14 (Ethiopia) line will be fine map for the identification of candidate genes. Genotype by sequence of RIL resulted in the identification of >10,000 SNP’s for IS18760 and QL3 populations. Based on recombination distance and marker quality approximately 500 SNP’s were selected to generate two high-quality loci recombination maps. Anthracnose resistant response of RIL are being evaluated in field and greenhouse in order to precisely locate resistant locus. Two Kompetitive Allele Specific Primers (KASP) flaking the resistant locus Cs-SC112 were developed to fine map this genomic region. The genotyping of over 1,200 F_2:3 segregating progenies have identified 37 recombinant individuals, which are being evaluated in the field for anthracnose resistance response. New genetic markers are being developed to completely dissect these recombination events and to identify candidate genes. The results of this research will provide valuable information about the inheritance of anthracnose resistance response, and will generate the necessary tools to pyramid multiple resistant loci by marker-assisted selection.