Effect of Mycorrhiza on the Growth of Paraserianthes falcataria (L.) I.C Nielson under Hg-contamination

Mercury (Hg) at 50 mg kg^-1 is toxic to microorganisms, but its toxicity to Arbuscular Mycorrhizae Fungi (AMF) associated with Paraserianthes falcataria (L.) I.C. Nielsen has not been widely studied. Effect of Hg on seed germination was evaluated to measure the rate of seed deterioration. The toxic concentration obtained from the germination study was used to adjust the Hg concentration of media for the seedling growth study. The aim of this study was to evaluate the effect of Hg on mycorrhiza. The research was conducted in two consecutive experiments. Rate of germination of seed under mercury condition, soil physicochemical properties, the profile of symbiont (AMF), and soil microbial activities were measured. Microbial activities were assayed using Fluorescein diacetate (FDA) hydrolysis and phosphatase activities. Seed germination was inhibited to 21.67–81.85% by Hg in a range of 30-100 mg L^-1 Hg. The medium dose was chosen to evaluate the behavior of the symbiont (AMF) and its effect on soil physicochemical properties. Mercury inhibits microbial activity. Combination of compost and AMF treatment reduced toxicity effect while increasing soil microbial activity.