Abstract
Heat stress/high temperatures during flowering and pod development is increasingly becoming a major constraint in chickpea production. Heat tolerant varieties are needed for improving chickpea yields in warm season environments and late sown conditions. With an objective of identifying genes and/or markers associated with heat tolerance for accelerated development of heat tolerant chickpea varieties RNA-Seq based transcriptome analysis was performed. Vegetative (leaves and roots) and reproductive (leaves, roots and flowers) tissues of six contrasting heat responsive (tolerant - ICCV 92944, ICC 1356, ICC 15614 and sensitive - ICC 5912, ICC 4567, ICC 10685) genotypes were selected for the study. A total of ~504 million reads were generated and alignment of these reads against the comprehensive chickpea transcriptome assembly (CaTA v2) resulted in covering of 44,185 out of 46,369 transcript assembly contigs. A total of 6,799 genes including 1,172 novel genes were significantly differentially expressed with a log2 fold change of ≥2 between tolerant and sensitive genotypes. A set of 56 differentially expressed genes belonging to abiotic stress family proteins was selected for further validation using quantitative real time PCR. Furthermore, >22,456 single nucleotide polymorphisms (SNPs)/INDELs were identified between lines that are the parental genotypes of two mapping populations (ICC15614 × ICC 4567 and ICC 1356 × ICC 4567). Novel genes along with the marker resources identified in this study should help breeders in developing heat tolerant chickpea lines in efficient manner.