【摘要】 研究了绿潮暴发过程漂浮浒苔藻体独特悬挂分枝现象,及其对高光强逆境胁迫的生理生态适应性。2012-2014年连续3年跟踪监测黄海绿潮漂浮浒苔漂移过程,发现海面漂浮藻体多为气囊主枝,因受高光强胁迫大部分逐渐变白死亡,而水下悬挂分枝藻体可以躲避高光强逆境胁迫生存下来。进一步对青岛海域漂浮浒苔气囊主枝与悬挂分枝进行叶绿素荧光参数及显微细胞结构观察,结果显示海面漂浮藻体气囊主枝多呈白绿色,F_v/F_m平均约为0.29,叶绿素含量约为0.32 mg/g,细胞质多数发生偏移或萎缩变色,且部分细胞形成生殖细胞囊或已放散出生殖细胞;而悬挂分枝多呈绿色且F_v/F_m较高平均为0.6,叶绿素含量高达0.87mg/g,细胞质充实,仅少部分细胞萎缩。将气囊主枝与悬挂分枝放置于室内25℃、80μmol/(m2·s)条件下培养1周,发现气囊主枝的细胞均已形成繁殖细胞囊或已放散成空细胞,而悬挂分枝培养后则保持健康生长。该研究为进一步阐释黄海绿潮暴发机制提供了基础资料。更多还原

【Abstract】 In this paper,the phenomenon of filamentous branches hanging and their adjustment mechanism to the high light intensity for the free-floating green tide algae( Ulva prolifera) blooming in the Yellow Sea were studied. Yearly field surveys have been carried out throughout the occurring of green tide in the Yellow Sea during the past three years( 2012- 2014). The results showed that free-floating green algae can be divided into two parts—— floating air-sac and filamentous branches hanging under water. The floating air-sac bleached to death due to the stress of the high solar irradiance,whereas the filamentous branches could avoid specular adversity stress to survive. In July 2014,free-floating green algae were collected in the Qingdao Sea area,the air-sac and suspending filamentous branches were taken out for the measurement of chlorophyll fluorescence parameters,buoyancy and microscopic observation of cell structure. The floated air-sac Ulva thallus was white and green,and its F_v/ F_maverage value was about 0. 29,concentration of chlorophyll was about 0. 32 mg / g,with shrinking cytoplasm most skewed or discoloration. Suspending branches showed fresh green and its F_v/F_mvalue was relatively higher,the average was about 0. 6,and the chlorophyll concentration was 0. 87 mg / g,the thallus was filled with cell contents,and only a few cells began to shrink. Air-sac and suspending branches were separately cultivated at 25 ℃ under 80 μmol /( m~2·s) for a second observation a week later.Air-sac formed germ cell capsule and further formed the empty cells; suspending branches grew healthily and its shrinking cytoplasm ratio decreased after being cultivated.更多还原