Morpho-physiological and biochemical changes in finger millet [Eleusine coracana (L.) Gaertn.] under drought stress

Finger millet (Eleusine coracana L. Gaertn.) is a nutritious and climate-resilient crop with a C4 type carbon fixation pathway. The present study was aimed to assess the drought tolerance capacities of four finger millet genotypes based on their physiological and biochemical characteristics at three different phenological stages. Finger millet genotypes RAU 8, GPU 67, GPU 28 and MS 9272 were subjected to two water regimes, regular irrigation (control) and suspended irrigation (drought stress). During water regimes, morpho-physiological [biomass accumulation, leaf relative water content, and photosynthetic pigments] and biochemical changes [proline content, water soluble carbohydrates, antioxidant enzymes, and malondialdehyde content] were studied during seedling (18th day), vegetative (49th day) and early flowering stages (73rd day). The maintenance of growth especially root growth, biomass accumulation, the differential response in the concentration and changes of pigments, accumulation of proline, water-soluble carbohydrates and increased levels of antioxidant enzymes under drought stress play a major role in differential tolerance in finger millet genotypes that is conferred by the biplot analysis. The genotype RAU 8 is the most drought-tolerant genotype at all the three different phenological stages. Whereas the genotype GPU 67 was identified as sensitive at the seedling stage and its tolerance level was improved at vegetative and early flowering stages. The genotypes GPU 28 and MS 9272 were considered as drought sensitive at all three different phenological stages. Our results provide inputs to the breeders to select genotypes as parents and to design effective strategies in crop improvement programs.