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为揭示集约经营对毛竹林土壤固氮细菌群落特征的影响,采用变性梯度凝胶电泳(DGGE)和荧光定量PCR技术,分析集约经营0(CK)、10、15、20、25年毛竹林土壤固氮菌群落结构和丰度的变化规律,并探讨了影响土壤固氮菌群落的主要环境因素.结果表明:毛竹林集约经营导致土壤pH下降而速效养分积累;集约经营初期(10年)和后期(25年)土壤固氮细菌的群落结构与对照相似,而中期的15年和20年则与对照差异较大.固氮菌多样性指数和丰度均呈现先减少后增加的趋势,经营15年时达到最小值;土壤固氮细菌表现出对集约经营干扰的抵抗和恢复反应.冗余分析表明,土壤速效钾、水解氮、硝态氮和铵态氮的含量与固氮菌群落结构的变化有较强的相关性,表明集约经营措施导致了土壤固氮细菌短期的变化,但长期而言,不会对土壤固氮细菌产生不良影响.
In order to reveal the impact of intensive management on the characteristics of nitrogen-fixing bacterial community in Phyllostachys heterocycla cv. Pubescens, denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR were used to analyze the effects of intensive management 0 (CK), 10, 15, The results showed that the intensive management of Moso bamboo forest resulted in the decrease of soil pH and the accumulation of available nutrients. In the early stage of intensive management (10 years) and in the later stage (25 years), the soil microbial community structure and abundance changed regularly, and the main environmental factors influencing soil nitrogen- Year), the community structure of soil nitrogen-fixing bacteria was similar to that of the control, but there were significant differences between the 15-year and the 20-year metaphase and the control.The diversity index and abundance of Azotobacter showed the trend of decreasing and then increasing, Value.The soil nitrogen-fixing bacteria showed the resistance and recovery response to the intensive management disturbance.The redundancy analysis showed that the content of available potassium, hydrolyzed nitrogen, nitrate nitrogen and ammonium nitrogen had a strong correlation with the change of nitrogen-fixing bacteria community structure This indicates that short-term changes in soil nitrogen-fixing bacteria have been caused by intensive management measures, but in the long run, soil nitrogen-fixing bacteria will not be adversely affected.