土壤因子对西藏高原草地植物AM真菌的影响

Influence of Soil Factors on Interaction Between Arbuscular Mycorrhizal Fungi and Plants in Tibet Altiplano Pasture

于西藏高原中部地区就土壤因子对草地植物AM真菌的影响进行的研究表明:AM真菌孢子密度与菌根侵染率、菌根侵染强度无相关性;土壤质地对AM真菌孢子密度的影响明显大于土壤类型,壤土、粉砂土中AM真菌对植物根系的侵染率高于砂壤土;土壤pH与植物根固土壤孢子密度、菌根侵染率分别呈显著正相关和正相关,与菌根侵染强度则呈负相关;土壤有机质与AM真菌孢子密度呈负相关,菌根侵染效果则随土壤有机质含量的增加而提高;高磷土壤环境对AM真菌产孢和侵染均具不同程度的抑制作用,其中植物菌根侵染率随土壤有效磷含量的提高而呈显著下降;AM真菌对莎草科植物矮生嵩草、扁穗莎草根系具有良好的侵染效应。

The influences of soil factors on arbuscualr mycorrhizal fungi (AMF) were investigated in central Tibet altiplano pasture. The results showed that there were no corelation between the spore density which was defined as spore number per gram soil with mycorrhizal colonization; the effect of soil texture on AMF spore density is greatly larger than that of soil type. Mycorrhizal colonization in loam or silt were higher than that in sandy sandy soil. Soil pH showed significant correlationship with spore density, while soil organic matter content showed sig- nificant negative correlation. Mycorrhizal colonization was increased with increasing of soil oaganic matter con- tent, but decreased with increasing of soil Olsen-P content. It was also noticed that AMF well colonized cyper- aceae plants, such as Kobresia humilis and Cyperus compressus.