九龙江西陂库区沉积物甲藻孢囊萌发增殖研究

Research on the germination and proliferation of dinoflagellate cysts in the sediments of Xipi Reservoir in Jiulongjiang River

甲藻孢囊在甲藻的生命史中扮演着重要的角色,本文研究了九龙江西陂库区沉积物甲藻孢囊对温度和营养盐的萌发响应.结果显示,西陂库区沉积物中,甲藻门的丰度占微藻总丰度的1.9%～6.1%,主要为拟多甲藻属（Peridiniopsis）;硅藻门的丰度占微藻总丰度的81.8%～91.8%,绿藻门的丰度占微藻总丰度的6.1%～13.2%,其他门类的藻类较少.实验模拟条件下,较高的温度能促进甲藻孢囊的萌发,甲藻孢囊在20℃有更高的萌发率,不同温度下甲藻孢囊最终的萌发率差别不大,高温能促进甲藻孢囊的萌发,同样也有助于蓝藻和绿藻的萌发增殖,从种间竞争角度来看,15℃温度相对较低但更有利于甲藻孢囊萌发并增殖占据优势.以单磷酸腺苷（Adenosine Monophosphate,AMP）作为有机磷源能促进孢囊的萌发,提高甲藻孢囊的萌发速率,但不能提高孢囊的最终萌发率。

Given the importance of dinoflagellate cysts in eutrophication,this research investigated the impacts of temperature and nutrient condition on the germination and proliferation of dinoflagellates cysts in the sediments of Xipi Reservoir in Jiulongjiang River. The abundance of dinoflagellates ranged from 1. 9% to 6. 1% in the sediments,and the main species included Peridiniopsis. The dominant microalgae were diatoms,accounting for 81. 8% ～ 91.8% of the total algae abundance,followed by green algae（ 6. 1% ～ 13. 2%）. Significance of germination rate was observed in different temperature conditions,where high temperature promoted the germination process of dinoflagellate cysts. Though a temperature of 20 ℃ was favored for dinoflagellate,it was also conducive to proliferation of other cyanobacteria and green algae. It is suggested that the optimal temperature for dinoflagellates proliferation was15 ℃,contributing to its dominancy in algae communities under the experimental conditions. Adenosine monophosphate（ AMP） was the key organic phosphorus to facilitate the dinoflagellates cysts germination rate,whereas its contribution to final germination effectiveness was not obvious.