盐渍化地区刺槐、新疆杨和柽柳林中AM真菌特性及其影响因子

为研究生境异质性对AM真菌的影响,以内蒙古磴口、宁夏平罗和甘肃敦煌盐渍化地区中刺槐、新疆杨和柽柳为对象,分析不同树种林地土壤理化性质、土壤酶活性、根内AM真菌侵染状况及根际球囊霉素质量分数、AM真菌的菌丝密度和孢子密度,确定生境(如树种、土壤因子及气候条件)与AM真菌特性间的关系。方差分析结果表明,树种和样区位置对AM真菌的总侵染率、菌丝侵染率、丛枝侵染率、孢子密度、菌丝密度、总球囊霉素质量分数、土壤理化性质和酶活性均具有显著影响;变差分析结果表明土壤因子对AM真菌特性的影响最大,且其影响与树种和气候条件有关;相关分析进一步表明土壤因子及气候条件主要影响刺槐根际AM真菌的菌丝密度和孢子密度、柽柳根际的菌丝密度、新疆杨根内的丛枝侵染率、菌丝侵染率及其根际的孢子密度。以上结果表明,盐渍化地区AM真菌特性具有生境异质性,且其异质性主要由土壤因子的变化所致,而树种和气候条件对AM真菌特性的影响均相对较小。

Arbuscular Mycorrhizal Fungal Attributes under Monocultures of Robinia pseudoacacia, Populus alba and Tamarix chinensis in Saline Areas

In order to study the influence of environmental changes on AM (arbuscular mycorrhizal) fungal attributes, we sampled the root and soil samples from monocultures of Robinia pseudoacacia, Populus alba and Tamarix chinensis in saline areas located in Dengkou county of Inner Mongolia Autonomous Region, Pingluo county of Ningxia Hui Autonomous Region and Dunhuang county of Gansu province, measured soil physico-chemical properties, soil enzyme activities, easily extractable glomain and total glomain mass fraction, AM fungal colonization rate, spore density and hyphal density, and determined the relationships among AM fungal attributes, tree species, soil factors and climate conditions. Analysis of variance revealed that both of tree species and sampling sites significantly affected the total AM fungal colonization rate, hyphal colonization rate, arbuscular colonization rate, spore density, hyphal density, total glomain mass fraction,soil physic-chemical properties and enzyme activities. Variation partitioning showed that soil factors played the highest role in affecting AM fungi compared to tree species and climate conditions. Correlation analysis found out that soil factors and climate conditions were mainly correlated with AM fungal spore density and hyphal density in R.pseudoacacia rhizosphere, hyphal density in T.chinensis rhizosphere, the colonization rate of arbuscules and hyphae in P.alba roots, and spore density in P.alba rhizosphere. All the above results indicated that AM fungal attributes had dissimilarities among different saline areas, and those dissimilarities have been mainly attributed to the changes in soil factors since tree species and climate conditions had less influence on AM fungi than soil factors.