Study On The Community Characteristics Of Arbuscular Mycorrhizal Fungi In Soil Of The Community Of Natural Forest Of Toona Ciliata

Toona ciliate var.pubescens is a kinds of tall and deciduous arbor,belongs to Toona.And it is a national grade II protected plant.Besides it is a rare broad-leaved native timber species in the subtropical region of China.However,due to the poor natural regeneration ability of natural forests and the excessive human cutting of natural forests,the natural forests of T.ciliata var.pubescens have shown different degrees of decline in terms of primary productivity,habitat adaptability,and natural regeneration rate.Plants,the ground and underground ecosystems become a complex organism together.As a endangered arbor,the relationship between T.ciliata var.pubescens and its major symbiotic microorganisms(such as nutrient absorption,resistance formation)may be the one of the reason for T.ciliata var.pubescens to take survival strategy to face the endangered state.The reaserch is based on the study of the natural forest community of T.ciliata var.pubescens in Guanshan National Nature Reserve in Jiangxi Province,studies community composition of rhizosphere soil'AMF in different plant communities(typical community of T.ciliata var.pubescens,others)and its main influencing factors by morphological identification,learn the resource of main symbiotic microorganism of T.ciliata var.pubescens,and provide theoretical guidance for the restoration of rare and endangered species populations.The main results are as follows:(1)In this study,20 species of arbors and shrubs were used as the research object,and it isolates and identifies 3 genera and 22 species from their rhizosphere soils,including 6 species of Acaulospora(27.27%),15 species of glomus(68.18%),1 speices of Scutrllospora(4.55%).In the rhizosphere soil of the typical plant community of T.ciliata var.pubescens,the fungi of glomus were the most,and the Scutrllospora was the least,and its functionality might be changed.(2)The arbuscular mycorrhizal fungi infection characteristics of the main plant species in the natural forest of T.ciliata var.pubescens were analyzed.It was found that there were significant differences in the inoculation rate of AM fungi in the same plant with different characteristics of AM fungi in different plants.AM fungi have different choices for host plants,and the external environment has a certain influence on the infection of AM fungi.(3)Mycorrhizal infection rate was significantly positively correlated with organic matter.The dominant species of AM fungi were related to soil organic matter,total nitrogen,available phosphorus,and p H values.Soil nutrients were different in different plants in the same land..AM fungi are closely related to soil nutrients and interact with soil nutrients.(4)The infection rate of arbuscular mycorrhizal fungi was lower than the average value in the community of T.ciliata var.pubescens.The arbuscular mycorrhizal fungus has a low level of infection and has a great potential for improvement.