Genome Wide Association Mapping for Turcicum Leaf Blight (Exserohilum Turcicum) Re-sistance in Sorghum MAGIC Population

Turcicum Leaf Blight (TLB) caused by Exserohilum turcicum is among the most destructive diseases in sorghum causing upto 50 % or more yield losses. Different methods can be used to control TLB and among them is the use of resistant varieties coupled with the use of molecular markers. Therefore, the present study was undertaken to identify Single Nucleotide Polymorphism (SNP) markers and candidate genes associated with TLB resistance. Six multi-locus models of genome wide association study were conducted with Best Linear Unbiased Predictors (BLUPs) obtained from 198 sorghum MAGIC lines screened in Uganda in 2019 using 79,728 SNPs. Fifteen SNPs associated with TLB across seven chromosomes explained phenotypic variation ranging from 0.06-23.99% with the exception of chromosomes 2, 4 and 8. Potential candidate genes were predicted at 220kb down and up-stream of the associated SNP positions including NBS-LRR, NB-ARC and a remorin gene involved in disease response in plants. Results from the study give an insight into understanding the genetic architecture of TLB and the SNPs and candidate genes that can be useful for Marker Assisted Selection after validation. Key words: BLUPS, candidate genes, MAGIC, Tercicum leaf blight, single nucleotide polymorphism, sorghum