QTL mapping for heat stress tolerance in chickpea (Cicer arietinum L.)

Rising evidence of heat stress (HS) is appearing as one of the major challenges to crop performance including chickpea affecting plant growth and yield significantly. Unprecedented advancements in chickpea genomic resources have resulted in remarkable progress for genetic dissection of various complex traits including biotic and abiotic stresses. However, these genomic resources have been limitedly utilized for developing HS tolerance in chickpea. Thus, the present study was aimed to capture genetic variability and to identify HS relevant quantitative trait loci (QTL) using 206 F-2 individuals developed from DCP 92-3 x ICCV 92944 cross. Wide range of genetic variability for seventeen traits related to phenological, physiological and breeding importance was captured from the given population under HS condition by growing them in late sown condition. A total of 78 SSR markers were used for genotyping of the given F-2 individuals. Only 39 markers were fitted to Mendelian segregation and these were assigned to all linkage groups (LGs) except LG8, covering 859 cM of genome. QTL analysis revealed one QTL controlling primary branch number (PB) explaining 2% phenotypic variation (PV) on LG3 and another QTL related to chlorophyll content (CHL) on LG6 explaining 17.2% PV. In future, fine mapping of these QTL controlling genomic regions may enable uncovering the underlying candidate gene(s) contributing in HS tolerance. Thus, these genomic regions could be promisingly utilized for marker assisted breeding for developing heat tolerant chickpea genotype.