摘要
测定了采自香港2株球形棕囊藻和湛江1株等鞭金藻质体16SrDNA基因序列，结合GenBank中下载的32条同源序列，分析序列特征并构建分子系统树。发现600bp序列中有可变位点42个，简约信息位点33个，可变位点和简约信息位点分别为全序列的7．0％和5．5％。A＋T的含量（52．5％）略大于C＋G含量（47．5％），与已报道的棕囊藻属叶绿体和线粒体基因相似；在分子系统树上，同属藻种聚类在一起，属间遗传距离分别为0．0255-0．0503。棕囊藻属属内遗传距离0-0．0050，不同藻种相混杂，并未独立成支；质体16srDNA部分序列虽不能区分棕囊藻属内不同藻种，但能鉴定出GenBank中27个环境样品为棕囊藻属藻株，从而能确定其地理分布和相对丰度，对棕囊藻赤潮的预测预报具有重要意义。质体16srDNA在其他赤潮藻类物种鉴定方面的应用需要进一步研究。
Partial sequences of plastid 16S rDNA in the two Strains of Phaeocystis globosa isolated from Hong Kong and one Isochrysis strain isolated from Zhangjiang in South China Sea were determined,combined with 32 homologous sequences downloaded from GenBank, the sequence information were analyzed and phylogenetic tree were reconstructed. 42 variable sites and 33 parsimony-informative sites were found in the aligned 600 bp sequences, 7.0% and 5.5% sites were variable andparsimony-informative. The contents of （A＋T）（52.5%） were a little more than those of （G＋C）（47.5%）, which were similar to those plastid and mitochondrial genes of Phaeocystis.In the phylogenetic tree, algae strains of the same genus were clustered, and genetic distances among genus were between 0.025 5-0.050 3. Genetic distances within the genus Phaeocystis were less than 0.005 0, and different species were intertwined without isolated clade for each species. Although partial sequences ofplastid 16S rDNA could notdifferentiate different species in the genus Phaeocystis, which may due to the shortage of sequence length in the present study, the molecular marker sucessfully assigned 27 GenBank-downloaded environmental samples of various location to the genus Phaeocystis, which could be further used to determine their geographic distribution and relative richness of the genus Phaeocystis, implying their potentiality in forcasting and early warning of the redtide blooms of the genus Phaeocystis. Sequences of plastid 16s rDNA of other red tide algae should be further studied to determine their efficiency in species identification.
出处
《生态环境学报》
CSCD
北大核心
2011年第12期1898-1901,共4页
Ecology and Environmental Sciences
基金
国家自然科学基金(30770415
40106014)
暨南大学科研培训与创新基金(21611426)
