基于叶绿素荧光研究球形棕囊藻在富磷条件下的生长特性(英文)  

Predicting the growth of Phaeocystis globosa under phosphorus-replete conditions based on chlorophyll fluorescence determination

作　　者：蔡卓平[1] 黄伟伟[1] 段舜山[1] 

机构地区：[1]广州暨南大学水生生物研究所,广州510632

出　　处：《生态科学》2008年第5期410-413,共4页Ecological Science

基　　金：国家自然科学基金项目(40876074,30770336);广东省科技计划重点引导项目(2005B33201001);珠海市科技计划重大项目(PC20061045)

摘　　要：棕囊藻属于定鞭藻纲、定鞭藻目,广泛分布在不同海洋生态环境中。有报道指出,棕囊藻时常在北太平洋温带港湾、挪威海、北海、英吉利海峡及南极海域等地方引发的大规模有害赤潮。近年来,我国东海海域和南海粤东海域均发生较大面积的棕囊藻赤潮,给当地的水产养殖业带来了严重的影响。除此之外,棕囊藻具有特殊的生理机制,可以产生二甲基硫化物(DMS),对整个海域的气候状况,酸雨酸雾的形成以及全球硫循环都有重要的意义。本文以球形棕囊藻为研究材料,设置3组较高的磷浓度处理(5 mg·L-1、10 mg·L-1和20 mg·L-1),利用细胞记数和叶绿素荧光测定等方法研究了该藻在不同富磷浓度下的生长情况。结果显示,不同磷浓度下的藻体荧光值变化均呈现"S"型曲线,表明藻细胞的生长经历缓慢期,快速期和平缓期3个阶段;同时,试验所设置的磷浓度对球形棕囊藻的叶绿素荧光值有一定的影响,其中在5 mg·L-1 磷浓度下的藻体荧光值最低,在第7天只有802 μg·L-1,而在10 mg·L-1 和20 mg·L-1 磷浓度下的藻体荧光值较高,在第7天分别达到836 μg·L-1和850 μg·L-1,表明磷营养可以促进藻细胞的生长增殖,但在较高磷浓度下,这种促进作用不明显。结果还显示,较低浓度的磷(5 mg·L-1)减缓与限制了藻细胞的生长,在5 mg·L-1 磷浓度下的藻最大特定比生长速率和细胞密度分别只有0.704 d-1 和190 cells·mL-1。相对而言,20 mg·L-1 磷浓度下的藻最大特定比生长速率和细胞密度最高,分别达到了0.771 d-1和250 cells·mL-1。研究结果揭示,水体中的磷营养浓度的变化是导致藻细胞大量增殖的一个主要的外在因素,而利用叶绿素荧光来测定藻细胞生长是一种快速、简便和可靠的方法,在今后有害水华监测过程中应该多加利用,以更及时、准确地预测预报有害水华的发生,降低其对经济、环境和社会造成的潜在危�Phaeocystis is a genus of marine phytoplankt0n with a worldwide distribution. Species of this genus shares a polymorphic life cycle including free-living single cells and colony-forming cells. Phaeocystis globasa has been described to develop colonies with variable structure, shape and size and is an annual bloom forming species in the eutrophicated coastal zones of the North Sea. In China, a dense bloom of P globosa first occurred in the coastal waters of southeast China in 1997 and reoccurred frequently in 1999, 2000, 2003, 2004 and 2005. It has been well documented that Phaeocystis is a prodigious producer of DMSP, acrylic acid, and the volatile DMS. Besides, various negative effects of Phaeocystis blooms on higher trophic levels of commercial interests, like fishing, aquafarming and tourism have been reported. Hence, Phaeocystis colony blooms are generally reported as undesirable and have been defined as non-toxic Harmful Algal Blooms （HABs）. On the other hand, excessive phosphorus （P） enrichment via industrial and agricultural inputs has been proved to play a particular important role in the cell proliferation of microalgae, resulting in massive occurrence of HABs along the coastal water. Numerous studies have been carried out to predict microalgal growth in response to nutrient variations using traditional cell-counting methods with the help of microcopy and hemocytometer, which are relatively time-consuming and troublesome. In the present study, we evaluate the growth of P. globosa exposed to various P concentrations by measuring chlorophyll fluorescence ofmicroalgal colonies.

关 键 词：生长 球形棕囊藻 磷 叶绿素荧光 

分 类 号：Q948.8[生物学—植物学]