艾比湖湿地根际放线菌多样性及其环境响应

Correlation of Actinobacteria Community Diversity in Three Different Rhizospheres and Physicochemical Properties in Natural Reserve of Ebinur Lake Wetland

分别在春、夏、秋3个季节采集新疆艾比湖自然保护区盐节木、芦苇以及盐角草3种不同植被的根际土壤,利用PCR-DGGE技术研究土壤放线菌群落结构及多样性,同时测定7个理化因子,并对放线菌多样性与土壤理化因子的相关性进行分析。结果表明,艾比湖湿地不同植物根际、不同季节的放线菌多样性存在明显差异,其中盐角草群落放线菌的多样性最高,芦苇群落次之,盐节木群落最低;在盐节木和芦苇根际土壤中放线菌的多样性为夏季>秋季>春季,而盐角草根际土壤放线菌的多样性随春夏秋季节的变化依次增大。DGGE图谱中共测序22个条带,主要为放线菌亚目、微球菌亚目、弗兰克氏菌亚目、酸微菌亚目、棒杆菌亚目、动孢菌亚目和细菌域的未知类群。Shannon指数与土壤有机质含量、含水量呈显著正相关;与电导率、pH值、速效钾、有效磷和碱解氮等呈负相关。

Rhizosphere soil samples were collected from three sites of different vegetations（Halocnemum strobilaceum,Salicornia europaea,and Phragmites australis） in spring,summer and autumn,respectively in the Ebinur Lake Wetland,with which the research on the structure of community and the diversity of soil actinomycete were conducted. Accordingly,seven physicochemical characteristic factors were measured,and the relationship between the diversity of actinomycete and soil physicochemical characteristics were analyzed. The research suggested that diversity of actinomycete in different rhizosphere soils of vegetation were remarkably different,and differed in each season as well;the highest diversity belonged to Salicornia europaea community area, Phragmites australis community the second and Halocnemum strobilaceum community area lowest. With vicissitude of the season,the diversity of actinomycete in rhizosphere soil of Halocnemum strobilaceum increased gradually;the diversity magnitude of actinomycete in terms of the season was summerautumnspring in rhizosphere soil of Halocnemum strobilaceum and Salicornia europaea. In addition,22 bands from DGGE profiles were sequenced in total,the analysis of sequence indicated that the main populations of actinomycete in rhizosphere soil were Actinomycetales,Corynebacterineae,Micrococcineae,Frankineae,Acidimicrobineae,Kineosporiineae and unknown groups of bacteria. The results of correlation analysis showed that a positive relationship existed among the diversity of actinomycete（Shannon index）and soil organic matter,as well as moisture content,and a negative correlation among the Shannon index and electrical conductivity,pH,available potassium,available phosphorus and available nitrogen in Ebinur Lake Wetland.