农田利用方式对剑湖湿地土壤微生物多样性的影响

【目的】对剑湖湿地土壤微生物多样性进行研究,了解农田利用对剑湖湿地土壤微生物多样性的影响,为湿地土壤的合理利用及云南高原退化湿地的研究与保护提供科学依据。【方法】选择蔬菜地、小麦地、蚕豆地、油菜地和湖滨带5种不同农田耕种方式湖滨带土壤为采样点,采用正方形五点取样法采集土壤样品。试剂盒提取5个采样点的土壤总DNA,应用PCR-DGGE技术对5种土壤的细菌群落结构多样性指数(H')、丰度(S)和均匀度(J)进行研究,运用理化性质测定方法测定土壤有机质、总氮、总磷等理化指标。【结果】不同利用方式湖滨带土壤细菌多样性指数、丰度和均匀度均有所不同,天然湖滨带土壤的细菌多样性指数、均匀度、丰富度均高于农田耕种土壤;天然湖滨带土壤细菌群落结构与农田利用土壤相似性较低,单独聚为一类,农田耕种土壤细菌群落结构相似性较高,在82%的相似水平上聚为一类;在93%相似水平上5个土壤样品聚为5个类群;不同土壤样点间具有许多共同的条带,不同农田利用土壤细菌的优势种群均属于变形菌门(Proteobacteria)、草酸杆菌科(Oxalobacteraceae)、紫色杆菌属(Janthinobacterium)、杜擀氏菌属(Duganella)、埃希氏菌属(Escherichia)和链球菌属(Streptococcus)6大类。【结论】剑湖湿地湖滨带土壤微生物群落结构多样性较丰富。不同农田利用方式下剑湖湿地湖滨带土壤的理化性质有一定差异,影响了土壤微生物群落结构的变化,从而影响土壤微生物多样性的变化。

Effects of different farmland applications on soil microbial community structure diversity in Jianhu wetland lakeside zone

Objective]Effects of different farmland applications on soil microbial community structure diversity in Jianhu wetland lakeside zone were studied to provide scientific references for appropriate utilization of wetland soil, and research and preservation of degraded wetland in Yunnan plateau. Method]According to crop distribution and types of different farmland applications in Jianhu wetland lakeside zone, soil samples were collected in five different farmlands (vegetable field, wheat field, broad bean field, oilseed rape field and lakeside zone) using square five sampling method. Total DNA of soil for different five sampling spots was extracted using Kit. Diversity index (H'), evenness index (J) and richness index (S) of bacterial com-munity structure were studied using PCR-DGGE technology. Physicochemical indexes viz., organic matter, total nitrogen and total phosphorus were measured using physicochemical property assay method.Result]The results showed that soil samples of different applying farmlands had different Shannon-wiener diversity index, richness index and evenness index. Bacterial di-versity index, evenness index and richness index in wetland lakeside zone were higher than those in farmland soil. Bacterial community structure of wetland lakeside zone presented lower similarity to that of farmland soil, so it was clustered into a group alone. Bacterial community structure in different types of farmland soil shared high similarity (82%), so they were clustered into a group. Samples from the five collection spots were clustered into five groups at the similarity level of 93%. Mutual bands were found among different soil samples. Soil bacteria dominant species belonged to six categories, viz., Proteobacteria, Ox-alobacteraceae, Janthinobacterium, Duganella, Escherichia and Streptococcus.Conclusion]Soil microbial community struc-ture diversity of different farmland in Jianhu wetland lakeside zone was abundant. Differences existed in soil physical and chemical properties, which affected the changes in soil microbial community structure and soil microbial diversity.