不同施肥模式对雷竹林土壤真菌群落特征的影响

为探明施肥处理对雷竹林土壤真菌群落特征的影响,采用末端限制性片段长度多态性(T-RFLP)和荧光定量PCR技术,分析有机肥(M)、化肥(CF)、化肥配施有机肥(CFM)、化肥配施有机肥加覆盖(CFMM)及不施肥(CK)处理土壤真菌群落结构和数量特征.结果表明:施肥显著影响真菌群落结构与多样性,表层(0～20 cm)土壤中M、CFMM处理与CK,亚表层(20～40 cm)土壤中CF、CFMM处理与CK之间真菌群落结构均存在明显差异;且表层土壤中CF、CFMM处理真菌Shannon指数和均匀度指数显著低于CK.M、CFM处理表层土壤真菌数量显著高于CK.土壤有机质、全氮、铵态氮和速效钾含量显著影响了真菌群落结构的变异;全氮、铵态氮、硝态氮含量与真菌数量均呈显著正相关.表明雷竹林表层和亚表层土壤中真菌群落对施肥处理的响应存在明显差异,表层土壤真菌群落明显受有机质添加的影响,而亚表层则对化肥投入较为敏感;施肥对真菌群落多样性的影响主要集中在表层土壤.

Effects of different fertilization regimes on soil fungal communities under Phyllostachys violascens stand

In order to investigate the effect of fertilization on soil fungal community of Phyllostachys violascens stand, we characterized the abundance and community structure of soil fungi using the methods of terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR. The experimental treatments included blank control (CK), chemical fertilizer (CF), organic manure (M), mixture of chemical fertilizer and organic manure (CFM) and mixture of chemical fertilizer and organic manure plus mulching (CFMM). The results showed that fungal community structure and diversity were markedly affected by different fertilization regimes. In 0-20 cm soil layer, CF and CFMM treatments resulted in a significant reduction of Shannon and evenness indices. Soil fungi under CK, M, CFMM treatments in 0-20 cm soil layer and CK, CF, CFMM treatments in 20-40 cm soil layer formed independent community structures. Soil fungal abundance showed significantly positive correlation with the concentrations of soil total nitrogen, ammonium nitrogen and nitrate nitrogen. Organic matter, ammonium nitrogen, available phosphorus and available nitrogen concentrations were the main factors that influenced the variation of fungal community composition. The above findings indicated that 0-20 cm and 20-40 cm soil layers had different characteristics in response to different fertilization regimes under P. violascens stand. The soil fungal community in the 0-20 cm layer was mainly affected by soil organic matter, while that in the 20-40 cm layer was sensitive to the input of chemical fertilizer. The effect of fertilization on the diversity of fungal community mainly occurred in the 0-20 cm soil layer.