Dhaliwal, InderpreetRanjeet Singh2024-01-042024-01-042022Ranjeet Singh (2022). Development and validation of kaspmarkers for heat stress tolerance QTLs in wheat (Triticum aestivum L.) (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810205650A panel of 24 wheat genotypes, comprising 19 heat tolerant, 3 heat susceptible and 2 parental lines were evaluated under timely and late sown conditions during rabi 2020 in a Randomized block design with an aim to develop and validate a KASP assay for heat stress tolerance. Eleven major reproductive traits, including grain yield, plant height and days to maturity were evaluated. In general, there was a reduction in grain yield under late sown compared to timely sown conditions. This trait was highly variable among the 24 genotypes as some of them (KSG1188, KSG089, KSG849, KSG1189 and KSG1195) exhibited very low reduction in yield, indicating a tolerance to heat stress for maintaining the desired yield levels. Similar behavior was observed for other plant traits also, viz, days to heading, days to maturity, mean grain weight per main spike, spikelet fertility and tiller number per meter square. There were also some genotypes that displayed increased height and biomass under late sown conditions, which is rare for a heat stressed crop. The stability in performance of the genotypes may be attributed to heat stress tolerance under late sown conditions. Since the QTL for stress tolerance were already described in an earlier study, the identified GBS-SNPs were converted to 4 KASP primers following standard procedures to run the KASP assay on this panel. Of these four primers, 2 were successful in allele calling, thereby giving an efficiency of 50%. Hence, converting these identified GBS-SNPs into KASP assays can successfully be used to differentiate the genotypes or populations for heat stress related QTL.EnglishThesis