土壤类型和树种对根际土丛枝菌根真菌群落及其根系侵染率的影响

The effects of soil types and plant species on arbuscular mycorrhizal fungi community and colonization in the rhizosphere

为合理利用丛枝菌根(Arbuscular Mycorrhiza,AM)真菌促进喀斯特退化土地植被恢复,采用形态学方法研究了土壤类型(石灰土和黄壤)和宿主植物种类(紫弹树(Celtis biondii Pamp)、红锥(Castanopsis hystrix)和单性木兰(Kmeria septentrionalis Dandy))对AM真菌群落结构的影响。研究共分离鉴定了2属14种AM真菌,其中幼套球囊霉(Glomus etunicatum)是石灰土和黄壤共有的优势种,石灰土特有的AM真菌包括地球囊霉(G.geosporum)、白色球囊霉(G.albidum)、双型球囊霉(G.ambisporum)、象牙白球囊霉(G.eburneum)和细凹无梗囊霉(G.scrobiculata),而波状无梗囊霉(A.undulata)是黄壤特有的AM真菌。土壤类型对AM真菌孢子密度,Shannon多样性指数以及侵染率具有显著影响;宿主植物种类与AM真菌Shannon多样性指数呈显著相关。石灰土紫弹树和单性木兰根际土AM真菌孢子丰度显著高于黄壤相同植物的,而红锥无显著差异;石灰土紫弹树和红锥的AM真菌物种丰富度及Shannon多样性指数均高于黄壤同种植物的。土壤类型对AM真菌孢子密度、物种丰富度、Shannon多样性指数和侵染率均有显著影响,对均匀度指数也有显著影响;植物种类对Shannon多样性指数有显著影响,且AM真菌物种丰富度、Shannon多样性指数和侵染率受土壤类型与植物种类交互作用的显著影响;土壤p H和全钾含量对AM真菌群落影响显著。因此,利用AM真菌促进喀斯特植物定植生长与植被恢复过程中,应该考虑喀斯特土壤AM真菌具有区域特异性和物种偏好性。

The objective was to research soil types （lime soil and yellow soil） and plant species （Celtis biondii Pamp, Castanopsis hystrix, Kmeria septentrionalis Dandy） effect on the community structure of AM fungi by morphology, to promote vegetation recovery in degraded land of karst. A total of 14 AM fungi belonging to 2 genera were found based on spore morphology, of which G. etunicatum was dominant species in both lime soil and yellow soil, Five AM fungal： G. geosporum, G. albidum, G. ambisporum, G. eburneum and G. scrobiculata species occurred only in lime soil. In contrast, A. undulata was only found in the yellow soil. Soil type significantly affected spore density, Shannon diversity index and colonization of AM fungi. Shannon diversity index of AM fungi was correlated with plant species. There was a significant differenee between AM fungal composition structure in different rhizosphere soils. The spore density of AM fungi in lime soil was higher than that in the same rhizosphere in the yellow soil, except Castanopsis hystrix. Both the AM fungal species richness and Shannon diversity index, in rhizosphere soil of Celtis biondii Pamp and Castanopsis hystrix,were significantly higher than in the yellow soil. Soil type significantly affected AM fungal spore density, species richness, Shannon diversity index and colonization. Evenness was significantly correlated with soil type. Furthermore, plant species had a effect on the AM fungal Shannon diversity index. The interaction between soil type and plant species affected AM fungal species richness, Shannon diversity index and colonization. Soil pH and total potassium content showed a significant influence on the AM fungal community structure. Therefore, we should take into account specific region and host plants preference before utilizing AM fungi to promote planting and recovery in the karst region.