艾比湖湿地三种植物根际土壤氨氧化细菌群落的多样性

Community diversity of ammonia-oxidizing bacteria of three plants rhizosphere in Ebinur Lake wetland

【目的】以艾比湖湿地盐节木(Halocnemum strobilaceum)、芦苇(Reed)及盐角草(Salicornia)三种植物为对象,研究其根际土壤氨氧化细菌(AOB)的群落多样性。【方法】利用PCR-RFLP的方法,构建氨氧化细菌amo A基因克隆文库,进行系统发育分析。结合三种植物根际理化因子特点,探讨三种植物根际AOB群落结构组成的特点。【结果】通过序列多态性分析表明,三种植物根际土壤AOB amo A基因克隆文库中的所有序列均属于β亚纲(β-Proteobacteria)中的亚硝化单胞菌属(Nitrosomonas)及Nitrosomonas-like,未发现亚硝化螺菌属(Nitrosospira)。三个AOB amo A基因克隆文库分别包括9个OTUs、12个OTUs和7个OTUs,其文库覆盖度均达99%以上,代表性强。三个文库的丰富度、Chao1指数、ACE指数、Shannon指数均为R>H>S。【结论】三种植物的AOB多样性为芦苇>盐节木>盐角草,并且其最优氨氧化菌群各不相同。本研究为系统认识艾比湖湿地植物根际氨氧化细菌群落多样性和结构组成提供了基础。

[ Objective ] In order to study the community diversity of rhizosphere soil ammonia-oxidizing bacteria, Halocnemum strobilaceum, Reed and Salicornia in Ebinur Lake Wetland were investigated. [ Methods] The clone libraries of amoA gene were constructed by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） , and phylogenetics were analyzed. To explore the community structure of rhizosphere amomonia-oxidizing bacteria, we combined rhizosphere physicochemical factors of the three plants. [ Results] Phylogenetic analysis of the amoA gene fragments showed that all of AOB sequences from shrimp of three plants rhizosphere were affiliated with Nitrosomonas or Nitrosomonas-like phyla, Nitrosospira phyla was not discovered. Three plants rhizosphere composition includes 90TUs, 12 OTUs and 70TUs respectively. Coverages of all libraries of the three plants rhizosphere were over 99% and strongly representative. The richness index, ehaol index, ACE index and Shannon index of the three libraries were as follows, Reed rhizosphere AOB was much higher than Halocnemum strobilaceum rhizosphere AOB, and Salicornia rhizosphere AOB was the lowest. [ Conclusion] This study provides a basis for understanding the community diversity and structure of rhizosphere soil ammonia-oxidizing bacteria in Ebinur Lake wetland.