Arbuscular mycorrhizal fungi enhance growth, physiological parameters and yield of salt stressed Phaseolus mungo (L.) Hepper

A pot experiment was conducted in a greenhouse to investigate the effect of two dominant indigenous arbuscular mycorrhizal fungi, viz. Funneliformis mosseae (F) and Acaulospora laevis (A), on the growth of Phaseolus mungo subjected to salinity levels of 4, 8 and 12 dS m−1. Mycorrhizal fungi alone and in combination improved the growth of the plants at all the salinity levels over that of the untreated control plants. However, a combination of F. mosseae and A. laevis resulted in maximum root and shoot length, biomass, photosynthetic pigments, protein content, mycorrhization, nodulation, phosphatase activity, phosphorus uptake and yield at the 8 dS m−1 salinity level. Peroxidase activity and electrolyte leakage were minimum at the 8 dS m−1 salinity level due to improved water absorption as a result of the highest mycorrhization occurring at this level of salinity. Nitrogen and potassium uptake decreased with increase in salinity and highest uptake of these nutrient elements was recorded in the treatment with both mycorrhizal fungi at a salinity level of 4 dS m−1. The results of the present experiment indicate P. mungo inoculated with F. mosseae and A. laevis can be successfully cultivated of at salinity level of 8 dS m−1. Saline soils with an electrical conductivity of nearly 12 dS m−1 were not suitable for growing this legume.