Effects of AMF infection on photosynthetic characteristics of tomato under salt stress

A pot experiment was conducted to study the effects of arbuscular mycorrhizal fungi (AMF) Glomus mosseae-2 on photosynthetic characteristics of tomato under different concentrations of NaCl (0.3%, 0.6% and 1%) stress. The results showed that salt stress reduced the net photosynthetic rate and light saturation point of tomato. Although AMF did not increase the light saturation point of tomato, it could increase the net photosynthetic rate, stomatal conductance, apparent quantum yield and CO2 carboxylation efficiency of the leaves, and improve chloroplast photophosphorylation activity, which was conducive to maintaining the ability of chloroplast to absorb light energy and improving tomato light energy conversion efficiency and CO2 utilization efficiency. When the inoculated and non-inoculated plants were treated with 0.3-0.6% NaCl, the photosynthesis decline was mainly affected by stomatal limitation, after 28 days of treatment with 1% NaCl, the decline of photosynthesis was mainly affected by non-stomatal factors, and inoculation with AMF could improve the photosynthesis of tomato under salt stress.