淡水湿地浮游病毒的空间分布

Large-scale spatial distribution of virioplankton in several wetlands in Hubei Province

在2006年3～7月间,对湖北省内15个营养水平不同的湿地水体中浮游病毒的分布规律开展了大规模研究。采用荧光显微直接计数法测定了浮游病毒丰度,同时还测量水体透明度、水温、pH、总氮、总磷、COD、叶绿素a浓度及活菌数。结果显示,浮游病毒丰度不但与活菌数和叶绿素a浓度显著相关(P<0.05),而且也与COD和水温极显著相关(P<0.01),这一结果说明有机物浓度和水温分别是决定淡水湿地中浮游病毒空间和时间分布的重要因素。进一步的分析还表明在富营养化水体中,浮游病毒与活菌数的相关性(P<0.05)高于与叶绿素a浓度的相关性(P>0.05),说明噬菌体(而不是浮游植物病毒)是富营养化水体中浮游病毒的优势种类。

Large-scale studies were carried out to see the spatial distribution of virioplankton in 15 wetlands with different trophic environments. Epifluorescenee microscopy was used to detect the abundance of virioplankton. Water transparency, water temperature, pH, total nitrogen concentration, total phosphorus concentration, COD, chlorophyll a and viable bacteria concentration were also recorded. Our results indicated that viral abundance was not only correlated to bacterial density and chlorophyll a concentration （P 〈0.05） , but also closely correlated to COD and water temperature（P 〈0.01 ）. This in turn suggested that organic substance and water temperature should be the key factors to influence the spatial and temporal distribution of virioplankton respectively. Moreover, viral abundance was more closely correlated to bacterial density（P 〈 0.05 ） than to ehl a concentration（ P 〉 0.05 ）in eutrophic freshwater wetlands, which indicated that it was bacteriophage （ but not phytoplankton virus） the dominant species of virioplankton in eutrophic freshwater wetlands.