Heat stress is a major detriment to crop growth and yield under the current patterns of climate change. The present study was aimed to compare the thermo-sensitivity of different camelina genotypes and optimizing exogenous sulphur to alleviate impacts of heat stress and to explore water relation attributes triggered regulations in yield related attributes of camelina. The experiment was conducted at University of Agriculture, Faisalabad in November 2019-20. The experimental design was used RCBD as split-split arrangement alongside three replications. The treatment comprised of heat stress T₁ = No stress (26^oC) and T₂ = Heat stress (32^o C) as main plot factor, two camelina genotypes G₆₁₁ = Camelina 611 and G₆₁₈ = Camelina 618 as split plot and exogenous sulphur application S₀ = 0 ppm and S₁₀₀₀ = 1000 ppm as split-split plot factors. Heat stress was induced at anthesis stage by covering the plants with transparent polythene sheet and exogenous application of sulphur was applied after imposition of heat stress. Heat stress badly affected the physiological parameters including water potential, osmotic potential and relative water contents. The traits related to water relations decreased by 36% under heat stress as compared to no stress. Yield related traits including no. of seeds, no. of branches, no. of siliques, 1000-seed weight and economical yield were negatively affected by heat stress. Exogenous application of sulphur proved helpful in reducing the heat stress effects in both genotypes of camelina. Sulphur at the rate of 1000 ppm enhanced the seed yield by 29% by improving the water potential and other physiological traits. The camelina genotype 618 performed better in heat stress condition as compared to camelina genotype 611. In crux, these findings indicated that thiourea as source of sulphur improved the heat stress tolerance in camelina, which might be attributed to maintenance of plant water status.

Key words: Camelina; Heat stress; Thiourea; Foliar spray; Genotypes