三疣梭子蟹（Portunus trituberculatus）两种养殖塘水体古菌的季节变化

摘要

结合基于古菌16S rRNA 基因的末端限制性片段长度多态性(T-RFLP)技术与克隆测序技术对象山港三疣梭子蟹–脊尾白虾混养模式下改良塘 M1(塘底铺网、四周铺砂的养殖塘)以及传统塘M2(土塘)不同季节水体古菌群落结构和多样性进行分析。结果显示，M1、M2养殖塘水体古菌群落均由泉古菌门(Crenarchaeota)和广古菌门(Euryarchaeota)组成。M1、M2水体古菌群落组成在养殖初期较相似，但随着养殖时间的推移，古菌群落结构组成发生显著差异。M2养殖水体古菌群落结构随时间变化的差异性大于 M1，说明 M2养殖生态古菌群落稳定性低于 M1，底铺网、四周铺砂的改良措施可以减少古菌群落变化的幅度。相关性分析发现，多样性指数高时，古菌分布受环境的影响较小；2种养殖塘水体古菌分布受温度、溶解氧、总氮和总磷的影响较大。%The dynamic changes and diversity of archaeal communities in two kinds of ponds (M1: the pond with sanded walls and netted bottom; M2: the traditional pond with soil) for the polyculture of Portunus trituberculatus-Exopalaemon carinicauda in different seasons were investigated. The study was conducted with a combination of cloning/sequencing and terminal restriction fragment length polymorphism (T-RFLP) analysis based on archaeal 16S ribosomal RNA. Physicochemical characters of the sea water were monitored at the same time to examine the relationship between environmental factors and archaeal communities. The results showed that the archaeal communities in both M1 and M2 were composed of Crenarchaeota and Euryarchaeota. Halobacteriales and thermoplasamatales in Euryarchaeota were the majority accounting for nearly half of the entire sample. Halobacteriales was more abundant than thermoplasamatales, however, it was the marked alteration in the relative abundance of thermoplasamatales that primarily led to the archaeal community shift. The structure of archaeal community in aquaculture water changed dramatically during the culture. The archaeal communities of M1 and M2 were similar at the beginning of the culture, but changed significantly over time. Principal component analysis showed that the variation in M2 was larger than in M1, which indicated the lower stability of archaeal community in the former. Redundancy analysis indicated that 84.2% of the archaeal community in M1 could be explained by the 9 factors measured in this study, while that M2 was also determined by other factors and only 35.7% was explained. The improvement of pond sediment could reduce the extent of changes in the archaeal community. Correlation analysis showed that the higher the diversity index was, the smaller the influence of environment on the distribution of archaea. In general, the distribution of archaea in pond water changed over seasons, and was greatly affected by temperature, dissolved oxygen, total nitrogen, and total phosphorus.