摘要
在2003年厦门港发生的一次裸甲藻赤潮中分离得到了纤小裸甲藻(Takayamapulchellum),并对其形态学进行了光镜和电镜的观察,该株藻细胞个体较小,长约20～23μm,宽约14～20μm。藻细胞外表卵圆形,细胞上壳有一条明显的S形顶沟,顶沟是特异性的反S形。与模式种相比,这一株裸甲藻细胞核更靠上部,大部分细胞横沟都没有偏移。纤小裸甲藻在盐度为28时比生长率最大,达到0.42,随着盐度下降,比生长率也跟着下降,当盐度下降到16时,生长率为0。盐度范围在8～16时,超过80%的藻类能存活48h;当盐度低于4时,生长率和存活率都为0。24～27℃是纤小裸甲藻的最适生长温度,比生长率超过0.50,当温度升到30℃时,生长率急剧下降到约0.35。毒素测定结果显示该株裸甲藻不含麻痹性贝毒和神经性贝毒。本株纤小裸甲藻大亚基D1～D2区序列长度为721bp,与基因库中该种的一株相似种同源性超过99%。对18株裸甲藻转录间隔区(ITS)序列建立的系统进化树显示,纤小裸甲藻和Karlodiniummicrum的距离最近,通过ITS序列建立的系统发育树大致能够把Akashiwo属、Karenia属、Karlodinium属和Takayama属与Gymnodinium属区分开来。
A strain of Takayama pulchellum was isolated during a bloom in Xiamen Harbor in 2003. Morphology was observed under LM and SEM. The vegetative cells are relatively small in size, ranging from 20 ～ 23μm long and 14 ～ 20μm wide. Cells are broadly oval with a conspicuous and well-defined sigmoid apical groove present on the epitheca. The apical groove is a characteristic reversed S-shape. The nucleus is located in the top part of the cell and most cells＇ cingulum do not displace, which are different from the type species. The growth rate reached the highest value, about 0.43, at salinity of 28 and dropped when salinity decreased. The cells ceased growing when salinity went down to 16, however, more than 80% of the cells could survive for 48h when salinity ranged from 8 to 16. Survival was not observed at salinity lower than 4. Best growth rate of Takayarna pulchellurn occurred at temperature of 24 and 27℃, which was above 0.50. Growth rate dropped sharply to about 0.35 when temperature increased to 30℃. PSP （paralytic shellfish poisoning） and NSP （neurotoxic shellfish poisoning） analysis did not reveal any toxin in this strain. The D1-D2 region of LSU （large subunit） rDNA and total ITS1-5.8S-ITS2 were amplified, cloned and sequenced. The partial LSU has 721bp and shares more than 99% similarity to the same species whose data was deposited in the Genbank. A phylogenetic tree was constructed using ITS sequence of 18 species, showing that Takayama pulchellum is closely related to Karlodinium micrum. The genus of Akashiwo, Karenia, Karlodinium and Takayama could be separated from Gymnodinium genus approximately using ITS sequence.
出处
《生态学报》
CAS
CSCD
北大核心
2006年第4期1021-1027,共7页
Acta Ecologica Sinica
基金
国家重点基础研究发展规划资助项目(2001CB409702
2001CB409709)
国家自然科学基金资助项目(40476053)
国家海洋局海底科学重点实验室资助项目(2004~2005)~~
关键词
厦门港
纤小裸甲藻
形态
生长
分子特征
Xiamen harbor
Takayama pulchellum
morphology
growth
molecular character
