Arbuscular mycorrhizal colonization increases yield of mungbean (<i>Vigna radiata</i> L.) at moderate level of salinity

Abstract

Mungbean is an important crop species cultivated in Southeast Asia and middle east regions where expanded salinity is a central point restricting plant development and yield profitability. In the present study, the impact of arbuscular mycorrhizal (AM) inoculation on improving biomass, plant resilience, nodulation, AM colonization, sporulation, yield, yield traits, nutrient concentration and uptake of mungbean under five salinity levels was investigated. The trial was laid in a factorial randomized completely block design with four replications. Five salinity treatments (0, 2, 4, 6 and 8 dS m(-1)) considered as the first factor and mycorrhizal inoculation as the second factor. The soil-based AM fungal inoculum containing 275 +/- 20 spores along with colonized Sorghum bicolor root sections was applied to each mycorrhizal pot. The results demonstrated that mycorrhizal inoculation increased yield and other yield contributing traits of mungbean relative to non-mycorrhizal plants under saline conditions. The increased yield and yield traits might be associated with increased dry biomass, plant resilience, nodulation, colonization, nutrient concentration and uptake of mungbean under AM inoculation. Plant resilience was noteworthy in mycorrhizal plants (96.6%, 87.6%, 81.3%, and 74.7% treated with 2, 4, 6, and 8 dS m(-1), respectively) than in non-mycorrhizal plants (92.4%, 76.9%, 68.2%, and 63.0%, respectively). The effect of AM inoculation was more conspicuous in soil with more salinity. Nutrient concentration increased in mungbean due to AM inoculation. At different salinity, the root biomass was also higher in AM inoculated mungbean, relative to non-inoculated plant. Eventually, nutrients uptake per plant increased by 21.4%, 26.0%, 20.1%, 20.2%, 23.7%, 22.9%, 32.4%, and 26.9% of N, P, K, S, Ca, Mg, B, and Zn, respectively, in mungbean due to AM inoculation relative to non-mycorrhizal plants. The plant dry biomass, nodulation, colonization, nutrient concentration, and uptake were increased by AM inoculation under saline and non-saline conditions leading to an improved yield of mungbean.