中文摘要：

应用荧光显微直接计数法,研究了2006年夏季长江口及邻近海域浮游细菌、浮游病毒数量的分布特征,探讨了它们与环境因子之间的关系。结果表明：（1）浮游细菌数量为（6.92×105~5.54×106）个/mL,浮游病毒数量为（2.22×106~9.97×107）个/mL。浮游细菌和浮游病毒数量的平面分布特征较一致,均为近海过渡区（B）〉近岸混水区（A）〉远岸清水区（C）;在垂直分布上,表层和10 m层的浮游细菌和浮游病毒数量均高于底层。（2）浮游病毒分布、表层浮游藻类生长以及10 m层水温变化是影响浮游细菌分布的重要因素,远岸表层浮游细菌分布还可能受硝酸盐浓度限制;营养盐供给及浮游细菌、浮游藻类的生长则成为影响浮游病毒分布的关键因子,温、盐变化对浮游病毒分布的影响不显著。

英文摘要：

Distribution of virioplankton and bacterioplankton and the relationships between their abundance and the impacting environmental factors of temperature,salinity,nutrients and chlorophyll-a concentration in summer of 2006 in Changjiang River Estuary and its adjacent East China Sea are studied using fluorescence microscopic count method.The results show that bacterioplankton abundance ranged from 6.92×105 to 5.54×106 individuals/mL with an average of（2.10±0.98）×106 individuals/mL and the virioplankton abundance ranged from 2.22×106 to 9.97×107 individuals/mL with an average of（1.06±1.23）×107 individuals/mL.The mean bcterioplankton and virioplankton abundances varied in the sequence of Area BArea A Area C.The results of correlation analysis show that the bacterioplankton abundance had significantly positive correlation with the chlorophyll-a concentration in the surface water（r=0.798,P0.01）,and negative correlation with the water temperature at 10 m depth（r=-0.619,P0.01）;the virioplankton abundance had a significantly positive correlation with the chlorophyll-a concentration in the surface water（r=0.674,P0.01）,and with the nitrate concentration in the bottom layer（r=0.526,P0.01）;there was a significant positive relationship between virioplankton abundance and bacterioplankton abundance in the surface water（r=0.720,P0.01）,in the water at 10 m（r=0.754,P0.01） and in the bottom water（r=0.777,P0.01）.The virioplankton abundance in our studied area is similar to the results from many other sea areas,and the bacterioplankton abundance is about an order of magnitude lower than that of virioplankton and similar to those from the past studies for Bohai Sea,Yellow Sea and East China Sea.The distribution of virioplankton,growth of planktonic algae in the surface water and the temperature at 10 m water are important impacting factors for the bacterioplankton distribution,and the nitrate concentration in surface water in Area C may also affect the bacterioplankton distribution.As for the