两种三疣梭子蟹养殖塘水体氨氧化古菌的季节变化

Seasonal variations of ammonia-oxidizing archaea in two kinds of ponds of Portunus trituberculatus

应用基于amo A的T-RFLP(末端限制性片段多态性分析)技术分析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)以及传统塘M2(土塘)水体不同季节氨氧化古菌群落结构和多样性。结果表明,M1、M2养殖塘水体氨氧化古菌绝大多数属于Nitrosopumilus Cluster。养殖过程中水体氨氧化古菌群落结构发生变化。两种养殖水体氨氧化古菌多样性指数和均匀度指数均在8、9月份时最低,且此时期氨氧化古菌群落分布与铵氮显著相关,说明8、9月份养殖环境比较脆弱,养殖塘水体氨氧化古菌群落分布受铵氮影响。T-RFLP分析结果表明各个时期不同养殖塘水体氨氧化古菌群落组成有差异。M2水体氨氧化古菌群落随时间的变化幅度大于M1,说明M2养殖塘氨氧化古菌群落稳定性低于M1,底铺网四周铺砂改良措施可以减少氨氧化古菌群落随季节的变化幅度。

The dynamic changes and diversity of ammonia-oxidizing archaeal communities in two kind of ponds（ M1： pond with sanded around and netted bottom,M2： traditional soil pond） of Portunus trituberculatus-exopalaemon carinicauda polyculture in different seasons were investigated by terminal restriction fragment length polymorphism（ T-RFLP） analysis based on ammonia-oxidizing amo A gene. The results showed that Cluster Nitrosopumilus was dominant in both M1 and M2. The community structure of ammonia-oxidizing archaea in aquaculture water changed dramatically during the breeding time. The diversity index and the evenness index of ammoniaoxidizing archaea were the lowest in August and September in both M1 and M2,which indicated that the environment was fragile in this period. RDA analysis showed that the distribution of ammonia-oxidizing archaea in pond water was greatly influenced by ammonium nitrogen in August and September. The result of T-RFLP showed that the community of ammonia-oxidizing archaea was different in M1 and M2 during the farming time and changed differently in each pond. Compared to M1,the community succession of ammonia-oxidizing archaea over time was larger in M2,indicated the community of ammonia-oxidizing archaea was more stable in M1. As such,the improvement of pond sediment could reduce the community shift of ammonia-oxidizing archaea by season.