互花米草沼泽湿地产甲烷古菌的多样性及垂向分布

Vertical distribution and diversity of methanogenic archaea in estuarine marsh dominated by Spartina alterniflora

为了深入探究影响河口沼泽湿地甲烷排放空间变异的关键因素，采用PCR-RFLP技术及测序分析对闽江河口互花米草沼泽湿地产甲烷古菌的多样性及垂向分布进行了研究.系统发育分析表明，闽江河口互花米草沼泽湿地产甲烷古菌的多样性划分为3大类群：甲烷杆菌目（Methanobacteriales）、甲烷微菌目（Methanomirobiales）和甲烷八叠球菌目（Methanosarcinales）.在不同的土壤深度，产甲烷古菌的群落结构呈现出空间变异的特征.0-10 cm土层占优势的产甲烷古菌菌属为Methanoregula和Methanobacterium，分别约占46%和43%；10-20 cm土层主要菌属为Methanoregula、Methanobacterium和Methanolobus，分别约占66%、13%和12%，Methanoregula为优势菌属；20-30 cm土层主要菌属为Methanoregula、Methanobacterium和Methanogenium，分别约占65%、11%和12%，Methanoregula为优势菌属.Shannon指数（H’）和Simpson多样性指数（D）计算结果表明，10-20 cm土层（H’=2.69，D=0.073）和20-30 cm土层（H’=2.47，D=0.093）产甲烷古菌的多样性明显高于0-10 cm土层（H’=1.60，D=0.292）.

To understand the key factors influencing spatial variability of methane emissions from estuarine wetlands, the vertical distribution and diversity of methanogenic archaea in the Spartina alterniflora marsh in the Min River estuary were investigated using PCR-RFLP and sequencing. Phylogenetic analysis showed that methanogenic archaea communities in the S. alterniflora marsh soil could be subdivided into three groups, Methanobacteriales, Methanomirobiales and Methanosarcinales. Community structure of methanogenic archaea showed spatial variability in different soil layers. Dominant genera in 0-10 cm soil layer were Methanoregula and Methanobacterium, which accounted for 46% and 43% of total methanogens, respectively. Main genera present in 10-20 cm soil layer were Methanoregula, Methanobacterium and Methanolobus, which accounted for 66%, 13% and 12% of total methanogenic archaea, respectively. In 20-30 cm soil layer, main genera were Methanoregula, Methanobacterium and Methanogenium, which accounted for 65%, 11% and 12% of total methanogenic archaea, respectively. Shannon index （H＇） and Simpson diversity index （D） suggested that diversity of methanogenic archaea in 10-20 cm （H＇=2.69,D=0.073） and 20-30 cm （H＇=2.47,D=0.093） soil layers were obviously higher than that in 0-10 cm （H＇=1.60,D=0.292） soil layer.