Effects of Arbuscular mycorrhizal fungi isolated from white clovers (Trifolium repensL) on soil bacteria and fungi

AbstractWhite clover potted experiments were performed to investigate the effects of seven indigenous arbuscular mycorrhizal fungi (AMF) communities isolated from different test plots subjected to long-term fertilisation on soil enzyme activities, number of soil bacteria and fungi. The results showed that the inoculation of arbuscular mycorrhizal fungi communities increased the mycorrhizal infection rate of the plants and promoted the growth of plants. The Mnp treatment was most effective. The shoot biomass, root biomass, potassium and nitrogen uptake of the white clover in Mnp treatment group were increased by 61.54%, 84.00%, 62.50% and 46.71% respectively, compared with those in non-inoculation treatment. The inoculation of AMF communities had little effect on the number of bacteria in the soil, but significantly increased the number of soil fungi. Mnk treatment group had the highest number of fungi in the soil, which was 9.91 times that of the non-inoculation treatment group. The catalase and dehydrogenase activities were both significantly improved in Mnp treatment by 28.12% and 205.38% respectively, compared with those of the control treatment (-M). The urease, invertase and cellulase activities reached the highest levels in the Mck treatment; they were increased by 142.79%, 41.17% and 77.62% respectively, compared with those of the control treatment. Pearson correlation analysis showed that the soil enzyme activity was not correlated with the mycorrhizal infection rate, but correlated with the spore number of the AMF community. The impact of AMF community on soil quality is important for us to understand the function of the ecosystems. Relevant study provides important guidance for maintaining the balance of the soil-plant system and the development of sustainable agriculture.Keywords: arbuscular mycorrhizal fungi (AMF)communitiessoil enzymeswhite clover AcknowledgementsWe wish to thank Chen Bao-Dong at State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, for his guidance and assistance during the trial. This work was supported by the National Natural Science Foundation of China (No. 41071336), and by the Knowledge Innovation Project of the Chinese Academy of Sciences (No. KSCX2-YW-N-41-05), and by the Open Fund Project of Provincial Key Laboratory of Jiangxi Province Academy of Sciences (2012-KLB-1).