温度对沉水植物腐解释放DOM及微生物群落多样性的影响

在5，10，20，35℃下研究了黑藻和马来眼子菜腐解过程中DOM的特性、细菌和真菌群落结构多样性的变化.结果表明，腐解结束时5，10，20，35℃下黑藻的干物质剩余量分别为初始干物质质量的59.13%、43.91%、32.61%和29.57%，马来眼子菜的干物质剩余量分别为初始干物质质量的69.13%、51.3%、30.87%和29.57%.升高温度一定程度上促进了植物有机碳和全氮释放，对全磷无明显影响（P>0.05）.采用平行因子分析法得到黑藻中含有2种类腐殖酸组分C1、C2和1种类蛋白质组分C3，马来眼子菜中含有3种类腐殖酸组分C1、C2和C3.温度升高使得腐解水体中DO和电导率的变化程度加剧，总体上4种温度下2种植物腐解水体中DO均呈现先下降后上升的趋势.通过高通量测序得到腐解前期（0~16d）参与黑藻和马来眼子菜腐解的主要细菌分别为变形菌门（Proteobacteria）和拟杆菌门（Bacteroidetes）；腐解中后期（16~68d）参与黑藻和马来眼子菜腐解的细菌分别以厚壁菌门（Phylum Firmicutes）和变形菌门（Proteobacteria）为主，温度对细菌群落结构无明显影响，而参与2种植物腐解的真菌均以子囊菌（Ascomycetes）最为活跃.

Research on the dissolved organic matter and microbial community diversity of submerged macrophytes decomposed under different temperature

The characteristics of DOM, the variation of bacteria and fungi in the decomposed process of H. verticillata and P.malaianus were studied under four temperatures (5, 10, 20 and 35℃). The results showed that the remaining biomass of H.verticillata were 59.13%, 43.91%, 32.61% and 29.57%, the remaining biomass of P.malaianus were 69.13%, 51.3%, 30.8% and 29.57%. The concentration of C, N was promoted by rising temperature, and there was no obvious effect on P(P>0.05). Two humic-like components (C1and C2) and one protein-like component C3 were identified in H.verticillata. Three humic-like components (C1, C2 and C3)were identified in P.malaianus. The variation of DO and CDC in the decomposed water were promoted by temperature. During 0~16d, the main bacteria involved in the decomposition of H.verticillata and P.malaianus were Proteobacteria and Bacteroidetes respectively. During 16~68d, the main bacteria involved in the decomposition of H.verticillata and P.malaianus were Phylum Firmicutes and Proteobacte respectively. The temperature had no obvious effect on bacteria community structure, and Ascomycetes was the major fungi during decomposition.