Protective effects of arbuscular mycorrhizal fungi on plants under low concentration of cadmium

To investigate the biological fixation in the application of low cadmium contaminated soil and in-situ utilization of rice safe production, this study adopts the pot experiment to compare and analyze the impact of arbuscular mycorrhizal fungi (AMF) on rice growth and seed cadmium content under low cadmium contamination conditions. The results showed that under the conditions of low cadmium contamination, rice and AMF formed a good symbiotic relationship, and the mycorrhizal dependency index of the host rice reached 120.43%. AMF infection can promote the expansion of the underground plant organs, and increase the adsorption capacity of roots. With AMF infection, the vegetative growth indicators, including rice plant height, root length, ratio of root to shoot, were higher than non-infected rice plants, especially the ratio of root to shoot increased up to 22.37%. Therefore, inoculum can significantly increase the rice nutrition biomass. Compared with the blank control group, the yield of rice seed increased by 12.61%. With the application of the mocrobial inoculim, the soil cadmium content threshold for ational food safety standards of rice seed increased from 0.20 mg/kg to 0.32 mg/kg, which guaranteed the in situ utilization of the low cadmium contaminated soil and the production safety of rice.