Identification of anthracnose (Colletotrichum lentis) race 1 resistance loci in lentil by integrating linkage mapping and a genome-wide association study

Abstract

Anthracnose, caused by Colletotrichum lentis, is a devastating disease of lentil in Western Canada. Growing resistant lentil cultivars is the most cost-effective and environmentally friendly approach to prevent seed yield losses that can exceed 70%. To identify loci conferring resistance to anthracnose race 1 in lentil, biparental quantitative trait loci (QTL) mapping of two recombinant inbred line (RIL) populations was integrated with a genome-wide association study (GWAS) using 200 diverse lentil accessions from a lentil diversity panel (LDP). A major-effect QTL (qAnt1.Lc-3) conferring resistance to race 1 was mapped to lentil chromosome 3 and co-located on the lentil physical map for both RIL populations. Clusters of candidate nucleotide binding-leucine-rich repeats (NB-LRR) and other defense-related genes were uncovered within the QTL region. A GWAS detected 14 significant SNP markers associated with race 1 resistance on chromosomes 3, 4, 5, and 6. The most significant GWAS SNPs on chromosome 3 supported qAnt1.Lc-3 and delineated a region of 1.6 Mb containing candidate resistance genes. The identified SNP markers can be directly applied in marker-assisted selection to accelerate the introgression of race 1 resistance in lentil breeding.