Morphological, physiological and biochemical responses of eggplant (Solanum melongena L.) seedling to heat stress.

High temperature stress under changing climatic conditions affects the eggplant like other vegetables. However, heat tolerant local germplasm of eggplant has not been identified currently. Hence, a brief research investigation was carried out to assess the heat tolerance potential of eggplant genotypes at seedling stage. The experiment was conducted under Completely Randomized Design (CRD), having four replications. One month old seedlings of four genotypes of eggplant (25919, Nirala, 28389 and Pak-10927) were subjected to high temperature, (45 degrees C/35 degrees C day/night) for a period of seven days. Heat stress tolerance ability of selected genotypes was evaluated by measuring the morphological (number of leaves/plant, leaf area, root shoot lengths, plant biomass), physiological (photosynthetic rate, stomatal conductance, rate of transpiration, water use efficiency, chlorophyll contents) and biochemical (Superoxide dismutase, Peroxidase, Catalase) characteristics. Genotypes exhibited considerably diverse behaviour at high temperature. Genotypes (25919 and Nirala) showed heat tolerance in all recorded variables, while genotypes (28389 and Pak-10927) were susceptible towards heat stress. So, it can be deduced from the findings that genotype 25919 is heat tolerant genotype and may be incorporated in vegetable breeding program in order to produce a heat tolerant variety having great potential to cope with adverse impact of elevated temperature stress. However, Pak-10927 genotype was found most heat sensitive among the studied genotypes.