Effects Of AMF On Growth And Rhizospheric Soil's Microbial Diversity Of Fortunella Margarita In Intercropping With Soybean

To research the effects of Arbuscular mycorrhizal fungi(AMF)on growth and rhizospheric soil's microbial diversity of Fortunella margarita(FM)in intercropping with Soybean,inoculated the grafted FM with Glomus etunicatum(G.e),a kind of AMF which has a high affinity to the FM's root,and managed with drip irrigation.Emphatically researched the changing of bacterial community's diversity(by molecular techniques of DGGE).The results showed that:(1)Compared with FM in control group(F),after hand-inoculated FM with G.e,the indexs of mycorrhiza infection(M%,m%,F%,et al.)increased significantly,and the group which G.e-inoculating and soybean-intercropping(F+A+S)ranked best.The mycorrhiza infection rate heightened significantly when intercropping with soybean(F+S).(2)Compared with the F group,the quantity of glomalin increased in G.e-inoculating(F+A)or F+S groups,the easily extractable glomalin-related soil protein(EEG)increased significantly in F+A+S group,and the total glomalin-related soil protein(TG)increased significantly in F+S and F+A+S groups.Compared with the F group,the organic carbon in FM's rhizospheric soil all increased,but the contrast only significantly in F+S and F+S+A groups.(3)Compared with F group,the activity of phosphatase and urease in FM's rhizospheric soil significantly increased,in F+A or F+A+S groups,but not the F+S group.The contrast of invertase between the test and control groups was not significant.(4)The total chlorophyll and net photosynthesis of FM's leaves increased in all test groups,the total chlorophyll's contrast between test and control groups all significant,but net photosynthesis' contrast significant only between F+A group and F group.(5)The height of FM increased in F+A and F+A+S groups,but the contrast between test and control groups was not significant.Except the taproot's length in F+A group,the taproot's length and fresh weight of FM increased significantly in test groups,compared with F group,and the fresh weight in F+A+S group was not higher than F+A and F+S groups.(6)The amounts of bacteria and actinomycetes of FM's rhizospheric soil increased significantly in test groups,so as the total microorganisms.The percent of bacteria in total microorganisms was upgraded,the percent of actinomycetes and fungi was impaired.(7)The result of DGGE showed that:The bacterial species increased significantly in F+A+S group,and the species diversity of bacterial community enhanced in test groups.The evenness index decreased along with the raising of measurements,the Simpson's dominantal species index got similar,the bacterial community tended to reach a stable structural or functional status.(8)The structure diversity of bacterial community gradually raised,along with the changes of measurements.The bacterial community structure was similar between the measurements of G.e inoculated or not,but dissimilar between soybean-intercropped or not.The research provided theories to achieve the goal of improving not only fruit's output and quality of Fortunella margarita,bat also the land utilization or yield,and the ecotope of agriculture.