Mechanisms Of The Interactions Between Trichoderma Virens And Suillus Luteus On Improving Resisitance To Damping-off Of Pinus Sylvestris Var.Mongolica Seedlings

In this paper,topics as follows were discussed:the inhibitory effect of Suillus luteus(N94)on the fungal strain of Rhizoctonia solani in vitro;under the potted condition(CK),the physiological response and root microecological change of Pinus sylvestris var.mongolica under the stress of Rhizoctonia solani after following different treatments:single inoculation of Trichoderma virens(T43)or N94,compound inoculation of N94 and T43;analysis of root system growth,branches and transcriptome differences of Pinus sylvestris var.mongolica under above different treatments.The results show that:(1)There was a good inhibitory effect on the fungal strain ofRhizoctonia solani in vitro.At 72h,the inhibition rate was the highest,which was 52.95%,and the inhibition rate of Fusarium oxysporum was only 18.57%in 144h.It was found that there was a fusing phenomenon in the Rhizoctonia solani.The inhibitory effect on the growth inhibition of the two kinds of pathogenic mycelium was poor,and the inhibition rate was only 26.19%,and the maximum inhibition rate of Fusarium oxysporum was only 12.50%.However,the inhibition effect on formation of the sclerotia was better.(2)Under the stress of Rhizoctonia solani,The effects of compound inoculation(N94+T43)on the antioxidant enzyme activity(SOD,CAT,POD),soluble protein and soluble sugar content in seedlings were significantly increased and much higher than other treatments;the conductivity and the content of malondialdehyde and proline are much lower than other treatments.The compound inoculation(N94+T43)control effect on Rhizoctonia solani was 66.27,and on F.oxysporum was 43.37.(3)The seedlings rhizosphere soil microecological changes under the stress of Rhizoctonia solani show that:compound inoculation(N94 + T43)can significantly increase the rhizosphere soil microorganism quantity,improve rhizosphere soil enzyme activity.Besides,the AWCD value of rhizosphere and the Shannon diversity index(H)were improved,and the utilization of rhizosphere microorganism on the carbon source of amino acids and esters was improved.(4)Compound inoculation(N94+T43)reduced the root crown ratio of biennial seedlings of Pinus sylvestris var.mongolica,significantly increased the total length,surface area,volume and other root parameters,and did not change the typical fish tail branch of the root.But it enlarged the root fractal dimension.(5)In transcriptome sequencing analysis,comparing compound inoculation(N94+T43)with other treatments,the up-regulated genes are cyclic nucleotide-gated ion channel,calmodulin,calmodulin protein,phenylalanine,chloroplast,which related to environmental adaptation function;meanwhile,the down-regulated genes are those paticipate in cutin,cork and wax biosynthesis.