Impact of Different Rhizobial Strains on Physiological Responses and Seed Yield of Mungbean [Vigna radiata (L.) Wilczek] under Field Conditions

Background: Water availability is a main controlling factor for agricultural productivity. Erratic monsoon and ever-growing population limit the water accessibility to mungbean and thus reduce its yield. Rhizobia-legume interactions are environmental friendly and are very well known for boosting the production potential of mungbean. But, the screening of new and better rhizobial isolates is essential to improve mungbean yield in sub-optimal conditions. So this study was conducted with the objectives to evaluate the rhizobial isolates for the physiological traits in mungbean and to measure the association of these traits with yield under moisture stress. Methods: In this field experiment during kharif 2016, five rhizobial strains of mungbean viz. Vigna 703 + PSB strain P-36, MR 63, MR 54, MB 17a and MH 8b2 were tested with respect and in combination with RDF at two water levels viz. control and drought. Moisture stress was created by withholding irrigations at flowering and pod formation stages. Result: Growth and physiological traits were altered under moisture stress. Rhizobial isolates MR 63 and MB 17a sustained higher yield over other rhizobial strains under both moisture regimes. These strains maintained higher RWC, leaf water potential and photosynthesis during stress and appear promising for drought tolerance.