The Community Structure And Species Diversity Of Entomopathogenic Fungi In The Tea Garden Soil Of China

Soil is an important reservoir of entomopathogenic fungi in the fields. The communitystructures and species diversities of the entomopathogenic fungi in the soil of tea gardensin Sichuan, Guangdong, Fujian, Hainan, Hunan, Jiangsu, Anhui, and Shandong provincewere studied. Four genus and11species of entomogenous fungi were identified. The11species are Beauveria bassiana, B. brongniatii; Metarhizium anisopliae, M. flavoviride;Isaria farinosa, I. fumosorosea, I. javanicus, I. cicadae, I. cateniannulata, I. tenuipes, andPaecilomyces lilacinus. Population dynamics of the11species were monitored by theselective medium technique. The populaiton of P. lilacinus dominated the community by apercentage of60.07%to the total density; and then followed by M. anisopliae of18.45%.The species diversity of view from four tea regions, Brillouin diversity index ofentomogenous fungi in the soil of Southern China Regions tea gardens is maximum for2.0289; Population density is also the largest for8940CFU/g dry soil. North of theYangzhi River Tea Region diversity index followed as1.8830. Southwest Regions diversityindex lowest1.0084. There are more than six species entomogenous fungi in the soil fromfour tea regions, the species of Southern China Regions reaches nine. P. lilacinus、M.anisopliae、B. bassiana and I. fumosorosea prevalent in four tea regions, but large changeson the population; M. flavoviride and I. javanicus in Southern China Regions and South ofThe Yangzhi River Tea RegionSouth were detected, but both of them in the SouthwestRegions and North of The Yangzhi River Tea Regions was detected respectively; B.brongniatii, I. farinosa and I. tenuipes were detected respectively in two regions,Southwest Regions and Southern China Regions, Southern China Regions and South ofThe Yangzhi River Tea Region, South of The Yangzhi River Tea Region and North of TheYangzhi River Tea Region; while I. cicadae and I. cateniannulata only in the North of TheYangzhi River Tea Region and Southern China Regions was detected.Species diversity of the community of entomogenous fungi in the soils of tea gardenschanged with the seasons. Different tendency appeared in the8provinces investigated. Thediversity indexes were above1.0411in the spring, the autumn and the winter, whiledecreased to0.0774in the summer in Chongqin city, which belong to the Southwest TeaRegion. The diversity indexes in Shandong and Anhui provinces, which belong to the.North of The Yangzhi River Tea Region, as well as that in Hainan Province shared thesame tendency, with the annual lowest deiversity indexes of0.0562,0.0512and0.0027,respectively, in the summer. But as to Guangdong province in the Southern China TeaRegion, and Hunan, Jiangsu provinces in the South of The Yangzhi River Tea Region, thediversity indexes peaked in the summer, and a maximum value of1.5300appeared inHunan province. According to the seasonal fluctuation of the diversity indexes, differenttendency appeared even among the provinces in the same Tea Region.This study showed that, there are others factors have great impact on communitydiversity and structure of entomogeneous fungi in the soil was found in tea gardens in eightprovince: complex plant structure, the soil of a tea garden, growing year of a tea garden,altitudes and artificial management. A more complex plant structure showed in a tea garden, a higher biological diversityof entomogeneous fungi in the soil was found in tea gardens in Guangdong Province. Themonocultured tea garden shaded by a tree layer had a diversity index of1.0651, which farhigher than that of0.3400of the garden without the tree layer. A tea garden with mutiplecultivars had higher diversity and richness of entomopathogenic fungi in the soil than thetea garden with monocultivar. Plant structure played an important ecological role inincreasing diversity of an entomopathogenic fungi community in a tea garden soil.Altitudes posed some effects on population density of the entomopathogenic fungi inthe soil of a tea garden. Investigation in Hunan province showed the population densitydecreased from7085CFU/g dry soil to2619CFU/g with the altitude increasing from100-150meters to over250meters. The diversity of entomopathogenic fungi in soil wasclosly related to the soil type in a tea garden. The species diversity were different among3kinds of soil types. The diversity was the highest in the Changsha soil with a speciesnumber of5and a diversity index of1.5535, while the Baojing soil and the Houshan soilshowed low species diversity with an index of0.0081and0.2101, respectively.Studies on tea gardens in Shandong province revealed growing year of a tea gardenhad effects on the diversity of the entomogenous fungi in soil. Three species ofentomogenous fungi were found in the new tea garden(Rizhao Jufeng1), and with apopulation density of5143CFU/g dry soil, which much higher than that of2864CFU/gin the old tea garden (Rizhao Jufeng2). But the diversity index in the old tea gardenpeaked a value of1.7082, compared with the index of0.8841in the new tea garden. Onemore species was isolated in the old garden. Therefore, the long-term growth andcultivation of tea conducive to the accumulation of diversity of entomopathogenic fungi insoil, the reason may be that the accumulation of soil organic matter, improvement of thephysicochemical properties and a more stable and long-term tea-insect-pathogenic fungiecological relationships.Artificial management on tea garden also posed some impact on the diversity of theentomogenous fungi in soil. Two species of entomogenous fungi were isolated in the wildtea garden (Shandong Taishan1), while4species were found in the artificial ecological teagarden (Shandong Taishan2). The population density of entomopathogenic fungi in thewild tea garden was3796CFU/g dry soil, some higher than2876CFU/g in the artificialecological tea garden. Artificial management looked like benefiting species diversity in soil.Compared with a wild tea garden, the diversity index in a well managed tea gardenincreased from0.6578to1.5719.An aboundant community of entomopathogenic fungi in soil benefits sustainablecontrol of pest insects in a tea garden.