本研究除探討兩株Amphora (雙眉藻屬)及兩株Navicula (舟形藻屬)矽藻，藻種編號Amphora AELCNU-ER 001、Amphora AELCNU-ST3 002、Navicula AELCNU-G4 003及Navicula AELCNU-ST 006等18S rDNA序列之親緣關係外，並探討三株雙眉藻屬矽藻藻種編號Amphora AELCNU-ER 001、Amphora AELCNU-ST3 及Amphora AELCNU-S2 004之生長速率、耐鹽度及油脂之含量。結果顯示:三株矽藻之耐鹽性範圍為20-50‰ 鹽度。在螢光顯微鏡下觀察經尼羅紅(Nile Red)染色後之三株雙眉藻屬矽藻皆有油脂反應，且缺氮培養3-7天的油脂反應，比正常f/2 medium 培養的油脂反應更明顯。此外，比對四株矽藻之18S rDNA序列之親緣關係顯示:外形相似的兩株Amphora (雙眉藻屬)矽藻之相似性指數為94.2%。而外形相似的兩株Navicula (舟形藻屬)矽藻之相似性指數為97.1%。兩株Amphora (雙眉藻屬)及兩株Navicula (舟形藻屬)矽藻之相似性指數介於88.8%-91.0%之間。進一步經NCBI網站比對，顯示目前NCBI之資料無法以此四株矽藻之18S rDNA基因序列，比對鑑定至種的分類階層。 In this study the molecular phylogeny of four brackish diatoms {Amphora AELCNU-ER 001, Amphora AELCNU-ST3 002, Navicula AELCNU-G4 003 and Navicula AELCNU-ST 006} were studied by analyzing 18S rDNA sequences. Differences between three strains of genus Amphora were studied with respect to growth rate, salt tolerant and lipid contents. All species were grown under identical conditions (temperature 32 ± 1◦C, light intensity 100 μmol photon m−2 s−1, salinity 2%, F/2 medium) and were harvested in the late exponential growth phase for DNA and lipid analysis. The results indicated that observed under fluorescence microscope by Nile red staining results, the three diatoms are all reflect oil reaction and nitrogen deficiency response straining 3-7 days of lipid than the normal medium more significant in oil response training. Furthermore, comparing of the 18S rDNA sequences between two Amphora species showed that the similarity index was 94.2%, between two Navicula species was 97.1%. However, comparing of the 18S rDNA sequences between two Amphora species with two Navicula species showed that the similarity index ranged from 88.8% to 91.0%. Except that, we found that the data of 18S rDNA gene sequences from NCBI information currently were not enough to be used to determine the taxonomic classification of Amphora and Navicula to species-level.
