WATER STRESS INDUCED CHANGES IN PHYSIOLOGICAL ATTRIBUTES OF MUNGBEAN

The production of mungbean [Vigna radiata (L.)] is adversely affected by drought in the tropics and sub-tropics. This study investigated the physiological responses of six mungbean varieties viz. BUmug 2, BUmug 4, BARI Mung-5, BARI Mung-6, Binamoog-5 and Binamoog-8 to non-stress (80% of field capacity) and water deficit (50% of field capacity) conditions. The experiment was laid out in a completely randomized design having four replications at the research field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur. The variety Binamoog-5 showed the highest level of physiological parameters related to drought tolerance, such as proline content (32.57%), xylem exudation (577.00 mg hr-1 and 383.70 mg hr-1) and total chlorophyll content (2.65 mg g-1 and 2.81 mg g-1) at preflowering and pod development stage, photosynthesis (38.94 μmol m-2 s-1 CO2 ), transpiration (15.00 mg H2 O/dm2 /h), and relative water content (66.14%), whereas that showed the lowest level of cell membrane thermostability (63.8%) under water stressed condition, followed by Binamoog-8. The measured physiological characteristics of other varieties were affected noticeably. Therefore, Binamoog-5 may be considered as a resource for drought tolerant genetic material.