Photosynthetic efficiency of tomato genotypes to elevated temperature

Abstract

The increasing temperatures due to global climate change may lead to changed geographical distribution and growing period of tomato conditions like high day and night temperature that may cause drastic reductions in tomato flowering and fruit set. Contemplating the problem of high temperature stress in future, the research was proposed and carried out in the pot culture to understand the genetic variation in the photosynthetic efficiency of 20 tomato genotypes to elevated temperature. The leaf temperature, stomatal conductance and transpiration rate of all the genotypes slightly increased within the range of 3-8% under elevated temperature. The photosynthetic rate was higher in IIVR-L genotype as compared to other genotypes under elevated temperature conditions which was obvious from its higher chlorophyll and soluble protein content. The higher soluble protein content in the genotype IIVR-L and lower chlorophyll fluorescence at all the stages under both the treatments compared to other genotypes might have resulted in higher photosynthetic rate by protecting the Rubisco protein and its activity and by maintaining the functional integrity of the photosynthetic apparatus.