EFFECT OF PEG-INDUCED DROUGHT STRESS ON MUNGBEAN PLANTS REVEALED RESISTANT VARIETIES BASED ON LEAF WILTING INDEX AND BIOCHEMICAL MOLECULES

Abstract

At the early vegetative growth stage, mungbean are mostly affected by drought, and it is also one of the most promising stages that can be used to screen for drought stress tolerance traits in multiple varieties. Therefore, this study utilized polyethylene glycol (PEG-6000) to induce drought stress towards selection of drought tolerance mungbean varieties in their early vegetative growth stage using both hydroponics and soil based systems. In this study, leaf wilting index and responses of biochemical molecules were used as the basic factors to determine the effect of PEG-induced drought stress among the mungbean varieties. Prior to the imposition of drought stress, germination potentials of the varieties were evaluated and all had germination = 60%. Except for Tvr29 and Tvr44, hydroponic system revealed that = 80% of the varieties had = 1 of their leaves significantly (P = 0.05) wilted. The highest LWI were recorded for Tvr49 and Tvr79. Re-evaluation of Tvr29, Tvr44, Tvr49 and Tvr79 using soil, shows that Tvr29 and TVr44 resisted drought stress. The hydrogen peroxide, superoxide radical and malondialdehyde contents decreased in TVr29 and Tvr44, and increased in Tvr49 and Tvr79 in comparison to the control. Tvr29 and Tvr44 had high proline content than Tvr49 and Tvr79. Based on LWI and biochemical molecules, this study revealed that Tvr29 and Tvr44 should be utilized where water deficit is a challenge to mungbean globally.