Diversity Of AMF And Their Effects On Rhizospheric Phosphorus And Nitrogen Of Dominant Plant In Phosphorus Enriched Area At Chaihe Basin

The Chaihe catchment in the south of the Dianchi basin is rich in P resources.Under the disturbance of human,the increase of soil and water loss will bring the P into Dianchi with the runoff,which affects the eutrophication and threats water safety.AMF as soil microorganism forms a reciprocal symbiotic with plant roots,which activates the insoluble P and N in the rhizospheric soil,promotes plants absorption of P and N,and reduce the loss of P in the phosphorous enriched area.To understand the AMF diversity of dominant plants and their effects on N and P in rhizospheric soil,it is important to understand the influence of phosphorus enriched area on watery environment.This study aims to understand the AMF diversity of the rhizospheric soil of dominant plants in the phosphorus enriched area of the Chaihe basin?Erianthus rufipilus?Coriaria nepalensis and Pinus yunnanensis?.The treatment of AMF were carried out by fungicide Benomyl,contrast the soil P and N forms contents between the AMF and without the AMF in the rhizospheric soil.Therefore,AMF affects soil P and N,and provides theoretical basis for the prevention and control of P loss,and ecological restoration of the phosphorus enriched area at Chaihe basin.The results as follows:1.TP and AP in the rhizospheric soil of the dominant plants in the phosphorous enriched area were significantly higher than that in the non-phosphorous enriched area?P<0.01?.The content of Al-P,Fe-P and O-P in the phosphorus enriched area were significantly higher than the non-enriched phosphorus area?P<0.01?.The Ca-P showed significant difference in the rhizospheric soil of Erianthus rufipilus and Pinus yunnanensis?P<0.01?.The different forms of inorganic phosphorus was:Fe-P>Al-P>Ca-P>O-P,the situation for different rhizospheric environments is:Pinus yunnanensis>Coriaria nepalensis>Erianthus rufipilus.The organic phosphorus in the phosphorus enriched area was significantly higher than the non-phosphorus enriched area?P<0.01?.The organic phosphorus in different forms was:ML-OP>HR-OP>MR-OP>L-OP.The soil N in the phosphorus enriched area was significantly higher than that the non-enriched phosphorus area?P<0.01?.The N in different rhizospheric environments was:Pinus yunnanensis>Coriaria nepalensis>Erianthus rufipilus,NH₄⁺-N>NO₃^--N.There was a significant difference in TOC between the two areas only in Pinus yunnanensis rhizospheric soil?P<0.01?.Soil pH only showed significant difference in the rhizospheric soil of Coriaria nepalensis?P=0.01?,and the rhizospheric soil showed strong acidity?pH<5.5?.2.The AM fungal community was obtained by Illumina Misq sequencing with 5orders,9 families,14 genera,57 species and 256 OTU.The dominant genera of AMF communities are similar,but their richness is quite different.The dominant genera of the phosphorus enriched area are:Glomus?Acaulospora?Scutellospora?Archaeospora and Ambispora,the dominant genera of the non-phosphorus enriched area are:Glomus?Paraglomus?Gigaspora and Diversispora.The species richness of the AM fungal community in the non-enriched phosphorus area in the rhizospheric soil of Coriaria nepalensis is higher species richness,the nitrogen fixation of Coriaria nepalensis created a relatively suitable soil environment for AM fungal community.3.There are different correlations between environmental factors and dominant genera in phosphorus enriched area:TP significantly correlated with Acaulospora?P=0.008??Sctellospora?P=-0.024??Paraglomus?P=-0.014?;AP significantly correlated with Acaulospora?P=0.005??Paraglomus?P=-0.004??Gigaspora?P=-0.017?;Al-P significantly correlated with Acaulospora?P=0.01??Paraglomus?P=-0.011??Gigaspora?P=-0.02?;Fe-P significantly correlated with Paraglomus?P=-0.01?;Ca-P significantly correlated with Acaulospora?P=0.006??Paraglomus?P=-0.024?;Ca-P significantly correlated with Paraglomus?P=-0.003??Sctellospora?P=-0.024??Gigaspora?P=-0.005??Acaulospora?P=-0.02?;ML-OP significantly correlated with Acaulospora?P=0.019??Paraglomus?P=-0.009??Gigaspora?P=-0.012?;MR-OP significantly correlated with Glomus?P=-0.028??Acaulospora?P=0.013?;HR-OP significantly correlated with Acaulospora?P=0.008??Sctellospora?P=-0.01??Paraglomus?P=-0.008?;TN significantly correlated with Acaulospora?P=0.006??Paraglomus?P=-0.009??Gigaspora?P=-0.035?;AN significantly correlated with Acaulospora?P=0.001??Paraglomus?P=-0.015?;NO₃^--N significantly correlated with Acaulospora?P=0.005??Paraglomus?P=-0.012??Gigaspora?P=-0.038?;NH₄⁺-N significantly correlated with Acaulospora?P=0.003??Paraglomus?P=-0.017??Gigaspora?P=-0.027?;TOC significantly correlated with Sctellospora?P=-0.018??Paraglomus?P=-0.01??Diversispora?P=-0.018?;pH significantly correlated with Glomus?P=-0.025??Sctellospora?P=0.003??Paraglomus?P=0.003??Diversispora?P=0.01?.4.The AMF in the phosphorus enriched area,the lower TP in rhizospheric soil?Coriaria nepalensis P=0.01,Pinus yunnanensis P=0.04?and AP.The reduction of AP in rhizospheric soil of different plants were Erianthus rufipilus 8.42%,Coriaria nepalensis 16.69%,Pinus yunnanensis 6.93%;The AMF significantly decreased soil L-OP?P<0.05?and increased other organic phosphorus.There was no significant difference in TN,and AM fungal community significantly increased rhizospheric soil AN?Erianthus rufipilus P=0.04,Coriaria nepalensis P=0.01 and Pinus yunnanensis P=0.02?.There was no obvious change in NO₃^--N,and there was a significant difference in NH₄⁺-N?P<0.01?.The AMF less significantly reduced TOC and increased soil pH.The study shows that phosphorus enriched area have their own unique AM fungal diversity compared with non-phosphorus enriched area,AMF accelerate mineralization rhizospheric soil dissolved P and N,promote the plant uptake of P and N,reduces the P and N in the soil,accelerate the process of plant recovery damaged ecosystem.Therefore,reasonably utilizes AMF combined with plants to restoration soil quality,not only can effectively control the migration of soil P and N loss phosphorus enriched area,but also have a positive contribution to reducing the risk of eutrophication in Dianchi.