Physiological Response of Mung Bean to Polyethylene Glycol Drought Stress at Flowering Period

Abstract

The study was carried out on the basis of the flowering period of mung bean (Phaseolus radiatus). The polyethylene glycol 6000 (PEG6000) was used to stimulate water stress. Four mung bean varieties with different drought resistances were used as materials in this experiment, in which the physiological indexes of mung bean for the identification of drought resistance were selected, and the response analysis of seven physiological indexes to different degrees of drought stress was measured by using polyethylene glycol 6000 (PEG6000) on different concentrations of 5%, 10% and 20%. The physiological mechanism was analysed on drought tolerance of mung beans. This test was to set up identification system for drought tolerance of flowering mung bean. The results showed that the relative conductivity after 6 days of 5% PEG treatment, the SOD activity after 6 days of 5% PEG treatment, the POD activity after 6 days of 10% PEG treatment and the ABA content after 6 days of 10% PEG treatment could be used as drought-tolerant identification for mung beans at flowering period. These four physiological indexes and drought-resistant index weighted grey correlation analysis results showed that the correlation order was successively SOD activity (0.8589) > ABA content (0.8290) > conductivity (0.7160) > POD activity (0.6637); and the grey correlation degree was greater than 0.6500 among the four physiological indexes.