Fine mapping studies identified a 113 kb region within ?QTL-hotspot_a? for seedweight and drought related traits in chickpea uri icon

abstract

  • A ?QTL-hotspot? region of 7 Mb size for drought component traitswas identified on CaLG04, using a recombinant inbred line (RIL)population (ICC 4958 × ICC 1882) in chickpea. Further, skimbasedgenotyping by sequencing (GBS) approach with large SNPmarkers delimited the ?QTL-hotspot? region into two sub-regions;viz, ?QTL-hotspot_a? of 139.22 kb and ?QTL-hotspot_b? of 153.36kb, on the kabuli draft genome sequence. In order to validateand identify more recombinations in the sub-regions for furtherrefinement, a fine mapping population with 1,911 lines was developed.Flanking markers of the two ?QTL-hotspot? sub-regionswere converted to KASPar assays and used to screen the finemapping population consisting of 1,911 lines. As a result, 19 F2:3recombinant families were identified. These families were phenotypedfor seed weight and other drought-related traits. Comparisonof genotype and phenotype data identified a genomic regionof ~113 Kb size within ?QTL-hotspot_a? responsible for 100 seedweight (100SDW) and other drought-related traits in chickpea.Subsequently, a syntenic study between the refined ?QTL-hotpsot?region and desi genome identified a 2 Mb region on Ca_LG_4pseudomolecule. Whole genome re-sequencing (WGRS) analysisof selected lines from each recombinant family identifiedseveral non-synonymous and InDel mutations within importantcandidate genes. Functional validation of these genes will helpdecipher the mechanism of drought stress tolerance in chickpea

publication date

  • 2017