模拟水流扰动对香溪河库湾浮游病毒-宿主动态的影响

Effect of stimulated water flow disturbance on the virioplankton-host dynamics in Xiangxi Bay

摘要:

【背景】浮游病毒是淡水生态系统的重要组成部分，在调节浮游细菌和藻类群落结构及调控系统物质循环过程中起着重要的作用。水库具有不同于湖泊的水动力过程，产生的扰动可能影响浮游病毒的调控功能。【目的】研究水力扰动对浮游病毒-宿主动态的影响，为阐释水库生境下浮游病毒生态功能提供理论依据。【方法】以香溪河库湾原水为材料，模拟不同流速扰动对病毒-宿主动态的影响；通过病毒丰度、宿主丰度、宿主裂解率、宿主溶源诱导率等参数的变化反映这种动态变化过程，并分析其与环境因子间的关系。【结果】0.05 m/s和0.10 m/s的流速扰动强度对浮游植物和浮游细菌生长有显著促进作用，但扰动对浮游病毒丰度的影响不显著；扰动能促进病毒介导的浮游植物和细菌裂解率上升，而且0.05 m/s扰动强度的促进作用大于0.10 m/s；同时，扰动显著降低了浮游植物溶源诱导率，但引起浮游细菌溶源诱导率的显著上升(P<0.05)。【结论】模拟扰动对浮游病毒-宿主动态过程产生了显著的影响，表明水库浮游病毒维持种群延续的生态策略可能与湖泊浮游病毒存在差异。

关键词:香溪河库湾;扰动;浮游病毒;浮游植物;浮游细菌;裂解率;溶源诱导率

Abstract:

[Background] As an essential part of freshwater ecosystem, virioplankton plays a key role in shaping the planktonic community structure and regulating the biogeochamical cycle of nutrients in water. The hydrodynamic process of reservoir is different from that of lake, and the disturbance may affect the virioplankton-host dynamics. [Objective] To reveal the effect of hydraulic disturbance on virioplankton-host dynamics and thus to lay a scientific basis for explaining the ecological function of virioplankton in reservoir. [Methods] The water sample from Xiangxi Bay was used and different flows were simulated. The parameters such as virioplankton abundance, host abundance, host lysis rate, and percentage of lysogenic host were monitored, and the relationship of the parameters with environmental factors was analyzed. [Results] The flow at 0.05 m/s and 0.10 m/s significantly promoted the growth of phytoplankton and bacteriaplankton but had no significant influence on the abundance of virioplankton. Disturbance enhanced the virus-mediated lysis of phytoplankton and bacteriaplankton, particularly the flow at 0.05 m/s. Meanwhile, the disturbance significantly reduced the phytoplankton lysogenic induction rate but caused the significant increase in the bacteriaplankton lysogenic induction rate (P <0.05). [Conclusion] The simulated disturbance had significant impact on the virioplankton-host dynamics, indicating that the survival strategy of reservoir virioplankton may be different from that of lake virioplankton.

Key words:Xiangxi Bay;disturbance;virioplankton;phytoplankton;bacterioplankton;mortality rate;lysogenic induction rate