Effects of Osmotic Stress Induced by Peg and NaCl on the Germination and Early Growth of Mung Bean

Abstract

    This study was performed to evaluate the effects of osmotic stress (measured by different water potentials) induced by Polyethylene Glycol 6000 (PEG) and NaCl solutions at the germination stage of five mung bean varieties (DX11, DX208, DX14, DX17, and DX22). Five water potentials: 0 (control), -0.15, -0.49, -1.03, and -1.76 Mpa were used as treatments in this study. The germination rates, root and shoot lengths, root and shoot fresh weights, and dry weights of the plants were measured. The results showed that the germination rate of the mung bean varieties decreased with increased NaCl or PEG concentrations. The germination rates of the mung bean varieties in the PEG treatments were higher than those in the NaCl treatments. In addition, low water potentials induced by NaCl (-1.76 Mpa and -1.03 Mpa) inhibited germination and seeding growth of all the mung bean varieties. The growth parameters of the mung bean seedlings, such as root and shoot lengths, fresh weights of roots and shoots, and plant dry weights, were reduced under low water potentials treated with either PEG or NaCl. However, more severe damage in seedling growth was observed in the NaCl induced treatments. Amongst five mung bean varieties used in this study, DX17 was more drought and salt tolerant than the other mung bean varieties.