Effect of Vesicular Arbuscular Mycorrhizal (VAM) Fungus and Rock-Phosphate Application on the Growth and Biomass of Moringa oleifera Lam. Seedlings under Salinity Stress

Abstract

Salinity is a devastating environmental stress factor that severely affects plant growth and development. Soil salinity often hinders plant productivity in both natural and agricultural settings. Vesicular Arbuscular mycorrhizal fungal (VAM) symbionts can mediate plant stress responses by enhancing salinity tolerance. Experiments were conducted in a greenhouse at the nursery of the Experimental Station of Forestry and Wood Technology Dept., Faculty of Agriculture, University of Alexandria, Abies region, Alexandria, from June, 2017 to May, 2018 and repeated at the same time in the second season. The obtained results showed that the inoculation with VAM and addition of RP led to enhance the growth significantly, in terms of survival, shoot height, shoot root ratio, root dry weight, shoot dry weight and total dry weight and minerals of the leaves of M. oleifera (N, P and K%) compared with the uninoculated ones. Chlorophyll a of M. oleifera was affected by salinity. Na Cl treatments caused a decrease in chlorophyll a and chlorophyll b content in both seasons. The largest increases in plants nutrient uptake (N, P and K) and decreasing in Na were observed with the VAM+RP treatment. The inoculated seedlings with VAM induced the highest value in Proline content in the first and second seasons compared with the uninoculated ones.The present study concluded that (M. oleifera Lam.) could tolerate salt concentration up to 171.1 mM in the presence of mycorrhiza. It is recommended; however, to inoculate the seedlings with VAM and (1g/kg soil) rock-phosphate application to enhance its growth and mitigate salinity stress.