In this work, we studied the effect of water stress on chlorophyll, carbohydrate and reducing sugar content in in vivo and in vitro plants of Macrotyloma uniflorum. The water stress was generated using by PEG-6000 in several concentrations ranging from 5% to 25%. Simulation of drought stress under in vitro conditions during the regeneration process constitutes a convenient way to study the effects of drought on the morphogenic and physiological responses. In vitro plantlets of M.uniflorum were obtained on L2 + IBA (2.45 µM) + BAP (8.88 µM) under water stress conditions induced by supplementing the medium with PEG at various concentrations ranging from 5% to 25%. The percent of response of the in vitro shoots adapted to low concentrations of PEG were more when compared to the plants adapted to high concentrations of PEG. The same kind of treatment was given to in vivo plants. The primary metabolites were decreased in the stressed plants both in in vivo and in vitro plants. Tissue cultured plants as well as in vivo plants as well as the in vivo plants were compared for their primary metabolite content. Chlorophyll, carbohydrates and reducing sugars increased in the stressed micropropagated plants. In vitro plants were better compared to in vivo plants.
