Studies On The AM Fungal Spores Identification In Poisonous Plants Rhizosphere And Its Regulation On Interactions Between Plants On Tibetan Plateau Alpine Meadow

The poisonous plants replace gradually the herbage in degradated grassland on the Tibetan plateau.The interaction between poisonous plant and herbage affect directly the direction of the succession of grassland such as competition and mutual.Arbuscular mycorrhizal(AM)fungi is one of the most important soil microorganisms in terrestrial ecosystems and can regulate interaction between plants,but also be influenced by the biological factors and non-biological factors such as the environment,the host plant species and strains of the fungi.So,in this paper,we research the poisonous plant rhizosphere of AM fungi community and the results of AM fungi mycelium network influences interaction relationship between poisonous plants and the herbage.The main results were as follows:(1)There was a tendency that the distribution of AM fungi community with the host plantsin the same ecological environment.We isolated 21 kinds of AM fungi belong to 9 species in this experiment,the frequencies of Glomus genera were the highest,Glomus caledonium had the highest frequency,94.4%;Followed by Glomus viscosum frequency of 77.8%.Saussurea japonica‘s and Gentiana macrophylla‘s rhizosphere of AM fungi species richness were 11 and 10 respectively,Anaphalis lactea‘s and Leontopodium japonicum‘s rhizosphere of AM fungi species richness were 8 in the medium level.And Lamiophlomis rotata‘s and Anemone rivularis‘s rhizosphere of AM fungi species richness were the least,is 5 and 4 respectively.The Glomus genera important worth of Anaphalis lacteais the highest in 6 kinds of poisonous plant rhizosphere of AM fungi community.AM fungi community structure similarity of Gentiana macrophylla and Saussurea japonic,Anaphalis lactea and Saussurea japonica was high.AM fungi community structure similarity of Anemone rivularis and Anaphalis lactea was the lowest;(2)AM fungi had the important impact on poisonous plants,through the influence of AM fungi mycelium network was not significant through the NM,CM and M treatment.From the analysis of the plant height,root length and biomass,AM fungi to slow down the competition effect of Elymus nutans,Poa pratensis combine with Saussurea japonica and promote the growth of Saussurea japonica.Also contributed to the competition between Polygonum viviparum and herbage.Especially in dealing with the CM treatment,Polygonum viviparum‘s biomass increased significantly,and reached a maximum,and herbage biomass decreased significantly at this time.(3)AM fungi mycelium network did promote the interactions between poisonous plant Saussurea japonicaand Elymus nutans,Poa pratensis,Kobresia pygmaea.Plant materials accessed near P element by AM fungi mycelium network under any P gradient,Saussurea japonica gain the ability of the P element is significantly higher than the other kinds plant,and three kinds of herbage results to gain the ability of the P element respectively: Poa pratensis>Elymus nutans>Kobresia pygmaea.They were characterized by mutual benefit.And with the increase of P through mycelium network in the soil.And the group of Saussurea japonicaand Kobresia pygmaea was inhibited by AM fungi mycelium network in the interaction under the gradient of P20 and showed the competition relations.But the group of Saussurea japonica and Kobresia pygmaea shows the mutual benefit relations under the gradient of P200.