PHYSIOLOGICAL RESPONSE OF MUNG BEAN TO RHIZOBIUM AND PSEUDOMONAS BASED BIOFERTILIZERS UNDER SALINITY STRESS

Plant growth, physiology, and quality parameters are affected by higher levels of ethylene under salinity stress. Certain plant growth promoting rhizobacteria (PGPR) can successfully be used to alleviate the detrimental effects of salinity-stress induced ethylene by degrading its immediate precursor 1-aminocyclopropane-1-carboxylic acid (ACC), through the activity of ACC-deaminase enzyme. A pot experiment was conducted to evaluate the effectiveness of Rhizobium and Pseudomonas containing ACC-deaminase for their ability to reduce the negative impact of salinity stress on physiology and quality parameters of mung bean. Results showed that salinity stress adversely affected the CO2 assimilation, stomatal conductance, photosynthetic rate, and chlorophyll contents in mung bean however; inoculation with either Rhizobium or Pseudomonas significantly reduced the adverse effect of salinity. It has been observed that co-inoculation of Rhizobium and Pseudomonas was the most effective treatment to reduce the inhibitory effect of salinity on CO2 assimilation rate, stomatal conductance, photosynthetic rate, and chlorophyll content. Co-inoculation also improved the nutrient balance and increased the phosphorus and protein concentration in grain of mung bean. The results suggested that such strains could be effective for reducing the deleterious effects of salinity on growth, physiology and quality of mung bean.