Arbuscular Mycorrhizal Fungi (Am Fungi) and phosphate solubilizing bacteria (PSB) on tolerance of tomato under salt stress

Abstract

The enhanced effect of arbuscular mycorrhizal fungus (AM fungi) and phosphate-solubilizing bacteria (PSB) on the salt tolerance of tomato (Lycopersicon esculentum L.) grown in pots was explored. Pot experiments were carried out in tomato inoculated with AM fungi (Glomus fasciculatum) and PSB (Bacillus megaterium var phosphaticum) under 1% NaCl stress. Salinity increases Na+ concentrations, but decreases K+ contents and K+/ Na+ in shoot and root significantly. Meanwhile, salinity reduces growth parameters such as root dry weight, shoot dry weight, total phosphate contents, chlorophyll contents and biological soil quality (phosphatase enzyme activities). Dual inoculation of AM fungi and PSB showed significant higher variation of the ion concentration (K+, Na+), plant growth parameters, available phosphate contents, phosphatase enzyme activities and the reduction of pH than other treatments. Under salt stress, the percentage of mycorrhizal root colonization of plants co-inoculated with AM fungi and PSB were higher than those plants inoculated with AM fungi alone. It is concluded that AM fungi inoculation with PSB application could synergistically enhance salt tolerance of plants.