Physiological introspection of leaf photochemical activity and antioxidant metabolism in selected indigenous finger millet genotypes in relation to drought stress

Abstract

Drought stress often impairs growth and yield of finger millets worldwide. The present study investigated the drought stress responses in four indigenous finger millets (Gangabali, Dengsameli, Kada and Badu) of Koraput compared to one improved variety (Bhairabi) under simulated drought condition at the early growth stage. The physiological and biochemical responses of indigenous finger millets were assessed through chlorophyll fluorescence technique, photosynthetic pigments, antioxidants, proline, protein and lipid peroxidation. The results showed that drought treatment significantly declined the photosystem (PS) II activity by declining the maximal fluorescence, maximum photochemical efficiency of PSII, yield of PSII photochemistry, electron transport rate and photochemical quenching with concomitant increase in minimum fluorescence and non-photosynthetic quenching compared to the respective control plants. Further, the present finding indicates that finger millet leaves responded to PEG-induced drought stress by significantly enhancing antioxidant enzyme activity. The proline accumulation was increased with increasing concentration of drought, which suggests that plants’ ability to resist the effect of drought. Based on the phenotypic response under drought stress, indigenous finger millet genotypes such as Gangabali and Badu showed superior drought tolerance capacity than the improved genotype (Bhairabi) during seedling stages. Overall, the results suggest that these indigenous finger millet genotypes may be beneficial for rainfed areas affected by drought stresses and can be used for future breeding programs.