城乡不同绿地中毛白杨土壤及根系真菌群落结构研究

土壤微生物在土壤养分循环和能量流动等生物过程中起着重要的作用,并且能敏感地响应环境条件的变化。本研究以天津市宝坻区毛白杨Populus tomentosa为研究对象,探究3种不同环境条件(社区绿地CG、公园绿地PG和高速公路旁绿地HG)对毛白杨土壤和根系真菌群落结构的影响。研究结果表明,3个绿地间土壤真菌Shannon多样性指数存在显著差异(HG>CG>PG);但根系真菌Shannon多样性指数无显著差异;此外,不同环境条件对真菌群落的组成起着重要作用。毛白杨土壤和根系真菌群落组成主要为丝盖伞属Inocybe、地孔块菌属Geopora、被孢霉属Mortierella、棉革菌属Tomentella、蓝状菌属Talaromyces、块菌属Tuber、层腹菌属Hymenogaster、链格孢属Alternaria、革菌属Thelephora、克努夫菌属Knufia和桩菇菌属Paxillus等,且差异分析表明丝盖伞属Inocybe、棉革菌属Tomentella和地孔块菌属Geopora的相对多度在3个样地中差异显著。比较分析土壤和根系样品发现土壤真菌群落α多样性显著高于根系真菌群落,两部位的真菌群落结构存在显著差异,块菌属Tuber的相对多度在根系样品中显著高于土壤样品。真菌群落功能预测表明腐生功能类群在不同环境条件下和不同部位间均存在显著差异。研究结果阐述了环境变化对土壤微生物群落中真菌组的影响,为森林生态系统的保护和林地可持续发展提供重要理论依据。

The fungal community structure in the rhizosphere soil and root of Populus tomentosa in different plantations

Soil microorganisms play an important role in biological processes such as soil nutrient cycle and energy flow, and can respond sensitively to changes in environmental conditions. In this study, Populus tomentosa was used to explore the effects of three different environmental conditions (community greenbelt, CG; park greenbelt, PG; highway greenbelt, HG) on the structure of rhizosphere soil and root fungal communities. The results showed that there were significant differences in soil fungal diversity index among the three environmental conditions (HG>CG>PG), while there was no significant difference in fungal diversity index of root samples. Environmental conditions played an important role in the composition of fungal community. Fungal community of soil and root of Populus tomentosa was mainly composed of Inocybe, Geopora, Mortierella, Tomentella, Talaromyces, Tuber, Hymenogaster, Alternaria, Thelephora, Knufia and Paxillus. The relative abundance of Inocybe, Tomentella and Geopora was significantly different under different environmental conditions. Comparative analysis showed that the alpha diversity of fungal community in soil samples was significantly higher than that in root samples. There were significant differences in the structure of fungal community between soil and root samples. The relative abundance of Tuber in root samples was significantly higher than that in soil samples. The prediction of fungal community function revealed that there were significant differences in saprophytic functional groups under different environmental conditions and different compartments. This study clarified the effects of the changes of environmental conditions on soil fungal microbiome, and provided reference for forest ecosystem protection and sustainable development of forest land.