西藏高原天然长芒草地丛枝菌根真菌接种效应

采用草地均匀打孔方法，就草地土壤未消毒条件下接种丛枝菌根（AM）真菌对长芒草(Stipa bungeana)的侵染效应以及对植物生长、吸磷效率、土壤微生物区系等的影响进行研究.结果表明,1)接种处理、不接种处理的菌根效应存在着明显的差异，多数接种处理根围土壤AM真菌孢子密度、菌根侵染率和侵染强度显著提高，但对丛枝丰度的影响相对较低.2)接种后AM真菌孢子密度对菌根侵染率具有极显著影响(r=0.7679**)；随菌根侵染率的增加，植株总干物重和吸磷总量均呈极显著提高，r值分别为0.7556**、0.8018**.3)与植株地上部相比，接种AM真菌对提高根系干物重、根系吸磷量和含磷量的促进作用相对较大.4)多数接种处理根际土壤酸性磷酸酶、碱性磷酸酶活性均呈一定程度的提高，根际土壤细菌数量显著增加，真菌、放线菌的数量变化则不甚明显.5)各接种处理对寄主植物的综合侵染效应在总体上呈Glomus mosseae+G. intraradices+Scutellospora calospora＞G. mosseae+G. aggregatum＞Glomus sp.＞G. mosseae＞G. mosseae+ G. etunicatum+G. intraradices+S. erythropa＞G. geosporum的趋势.

Field inoculation effect of AM fungi on Tibet plateau Stipa bungeana grassland

A field experiment was conducted on the Tibet plateau Stipa bungeana grassland to investigate the effects of arbuscular mycorrhizal fungi (AMF) inoculation on S. bungeana growth and its phosphorus uptake, and on soil microbial communities under unsterilized condition. The results showed that AMF inoculation increased the AMF spore density, infection rate and infection intensity in rhizosphere soil significantly, but had less effect on arbuscule richness. The infection rate of AMF increased with its increasing spore density, and the plant dry weight and P uptake of S. bungeana increased significantly with AMF infection rate. Similar results were observed in S. bungeana root dry weight and its P content. AMF inoculation increased the acid and alkaline phosphatase activities and bacterial biomass in rhizosphere soil, but had less effect on fungal and actinomyces communities. The infection effect of AMF varied with inoculation treatments, being in the sequence of Glomus mosseae+G. intraradices+Scutellospora calospora>G. mosseae+G. aggregatum>Glomus sp.>G. mosseae>G. mosseae+G. etunicatum+G. intraradices+S. erythropa>G. geosporum.