2019 ASHS Annual Conference

The growing evidence of global warming and, its potential impact on crop production has prompted several physiological and genetic analyses under high-temperature conditions. Optimum growing temperatures for tomato (Solanum lycopersicum L.) is less than 32°C and 24°C during day and night, respectively. Tomato is grown in sub-tropical and tropical regions of the world, where day and night temperatures exceed the optimum temperatures during summer which exerts potential heat stress on tomato production. With looming global warming, the temperature levels may go up even further. As a first step of improving tomato for heat stress tolerance, we performed the heritability estimate analysis for heat stress tolerance. From the same populations, we continued screening for heat stress tolerance with an objective of developing tomato lines with improved heat stress tolerance and fruit quality. Heat stress tolerance measured in terms of number of flowers and fruits per plant, and fruit setting index indicated that these traits have been improved significantly. Improvement was also made in fruit size, fruit smoothness, and blossom end rot in tomato lines. These are the encouraging progress towards the development of a new variety of tomato with improved heat stress tolerance and fruit quality.