Marker assisted mobilization of heat tolerance QTLs from Triticum durum-Aegilops speltoides introgression lines to hexaploid wheat

Most of the modern-day cultivars of spring wheat cultivated in the Indian sub-continent are susceptible to high-temperature stress during reproductive stages, and breeding for heat-tolerant genotypes is the plausible solution to mitigate effects of global warming on wheat productivity. Triticum durum - Aegilops speltoides backcross introgression lines were used for transferring seven heat tolerance QTLs to three different hexaploid backgrounds using marker assisted selection. A total of 164 BC2F3 progenies with different combinations of QTLs were generated and 40 progenies were evaluated in replicated trials across two years under normal (OE) and heat stress environments (HSE). Phenotypic evaluation and heat tolerance index (HTI) analysis over two environments showed that grain filling duration, spikelets/spike, tiller number, thousand grain weight, and yield showed were enhanced due to the introgression of heat stress tolerance QTLs. Progenies pauHTIL_10, 11, 12, 33, and 34 have shown higher yield than tested cultivars under OE with pauHTIL_10, 11, and 12 showed yields higher than 2.0 kgs/plot under OE and pauHTIL_14 showed yield of 1.6kg/plot under HSE. The progenies developed during this study can further be used for developing heat-tolerant wheat varieties.