AUTHOR=Jha Uday Chand , Nayyar Harsh , Palakurthi Ramesh , Jha Rintu , Valluri Vinod , Bajaj Prasad , Chitikineni Annapurna , Singh Narendra P. , Varshney Rajeev K. , Thudi Mahendar 

TITLE=Major QTLs and Potential Candidate Genes for Heat Stress Tolerance Identified in Chickpea (Cicer arietinum L.)

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.655103

DOI=10.3389/fpls.2021.655103

ISSN=1664-462X

ABSTRACT=In the context of climate change, heat stress during reproductive stages of chickpea (Cicer arietinum L.) leads to significant yield losses. In order to identify the genomic regions responsible for heat stress tolerance, a recombinant inbred line (RIL) population derived from DCP 92-3 (heat sensitive) and ICCV 92944 (heat tolerant) was genotyped using genotyping-by-sequencing (GBS) approach and evaluated for two consecutive years (2017 and 2018) under normal and late sown or heat stress environments. A high density genetic map comprising of 788 single nucleotide polymorphism (SNP) markers spanning 1125 cM was constructed. Using composite interval mapping (CIM), a total of 77 QTLs (37 major and 40 minor) were identified for 12 of 13 traits. A genomic region on CaLG07 harbours QTLs explaining >30% phenotypic variation for days to pod initiation, 100 seed weight as well as for nitrogen balance index explaining >10% PVE. In addition, we also report for the first time major QTLs for proxy traits (physiological traits like chlorophyll content, nitrogen balance index, normalized difference vegetative index, cell membrane stability). Further, 32 candidate genes in the QTL regions that encode the HSP genes, heat shock transcription factors, that are involved in flowering time regulation as well as pollen specific genes. The major QTLs reported in the present study, after validation, may be useful in molecular breeding for developing heat tolerant superior lines or varieties.