Resources Investigation Of Ectomycorrhizal Fungi In Pinus Sylvestris Var.Mongolica And Selections Of The Optimum Combination Of ECM Fungi With P.Sylvestris Var.Mongolica In Honghuaerji,Da Hinggan Mountains

To discuss the resources of ectomycorrhizal fungi in Pinus sylvestris forests and the selections of the excellent combination of ECM fungi-P.sylvestris var.mongolica in Honghuaerji of Da Hinggan Mountains in this research,we investigated the resources of ectomycorrhizal fungi in P.sylvestris forest,and then mycorrhizal seedlings synthesis researches of several separated dominant strains of Pinus was carried out by means of manual mycorrhiza,such strains cultivated in the potting and nursery conditions.respectively.Finally,the growth and physiological and biochemical indexes were detected under drought stress.The aims of our research are to understand the resources of ectomycorrhizal fungi and selection of the excellent combination of ECM fungi-P.Sylvestris var.Mongolica,providing the strain resources and excellent mycorrhizal seedings for protection and reconstruction of P.sylvestris forests in Honghuaerji.The results as follows:(1)A total of 57 fungal species belonging to 16 families and 26 genera were found in P.sylvestris forest of Honghuaerji.Among them,43 species were ectomycorrhizal fungi,accounting for about 75.4%.(2)Under potting conditions,2 months of P.sylvestris var.mongolica were synthesized with 5 species of ectomycorrhizal fungi.The colonization rate,growth and physiological and biochemical indexes of P.sylvestris var.mongolica were measured under well water and drought stress treatment.The results indicated that the indexes of all inoculated treatments were significantly higher than non-inoculated treatments.Inoculated with Suillus bovinus had the highest colonization rate(80%,71%),height(48mm,47.2mm),needle length(104.2mm,102.6mm)and biomass(0.816g/pot,0.924g/pot)in these two conditions.In addition,the colonization rate,height,needle length and aboveground diameter of mycorrhiza P.sylvestris var.mongolica were reduced by drought stress,while the dry biomass increased.(3)The SOD activity,POD activity and MDA content of P.sylvestris var.Mongolica were determined under drought stress.The results indicated that SOD activity and POD activity of inoculated treatments were significantly higher than non-inoculated treatments.while MDA content represented the opposite,indicating that ectomycorrhizal fungi could increase the POD activity and SOD activity and reduce MDA content of pine needles to enhance the drought resistance of mycorrhizal seedlings.(4)The wilting time of all inoculated treatments of P.sylvestris var.mongolica was longer than non-inoculated treatments under drought stress,and inoculated with S.bovinus had the longest time,it delayed 97.46h than non-inoculated treatments.Ectomycorrhizal fungi could also prolong the critical lethal time of host plant.(5)5 species of ectomycorrhizal fungi and annual P.sylvestris var.mongolica were synthesized under nursery conditions.The results indicated that colonization rate of inoculated treatments was all.more than 70%.The non-inoculated treatment were also colonized,whiler its colonization rate was far lower than inoculated treatments.It was lower 56.32%than average inoculated treatments.The resources of ectomycorrhizal fungi were abundant in Honghuaerji,so there were many mycelia in soil.Inoculated with S.bovinus had the highest colonization rate(84.6%),height(160.8mm),needle length(108.2mm)and biomass(5.496g/pot)in this condition.The pH values of seedlings rhizosphere soil was significantly decreased,and the pH values of all 5 inoculated treatments were lower than non inoculated treatments.(6)If we applied the mycorrhizal seedlings of P.sylvestris var.Mongolica to afforest,the S.bovinus should be considered at first.