早期微藻的鑑定與分類因受限於設備與技術，單純只藉由顯微鏡下觀察微藻的形態，以外觀之特徵作為藻類分類的基礎依據。近年來，因為分子生物技術的發展，微藻的鑑定與分類已能利用分子生物學的方法得到更進一步的輔助鑑定。由於實驗室先前的研究利用18S rDNA sequences作為本研究的三株綠藻的親緣關係的鑑定與比對，亦無法鑑定至種的分類階層，因此本實驗是進一步利用ITS sequences高度變異區域序列做為親緣演化關係的分析，因此取嘉南藥理科技大學藻類生態研究室 (AELCNU)現有的三株綠藻，包括編號Scenedesmus AELCNU-JDB1 008、Scenedesmus AELCNU-JDB1 009、及Chlorella AELCNU-STR 010等為藻種的來源，培養於f/2 medium。取對數生長期的藻類細胞進行ITS DNA之分析。DNA分析結果與NCBI基因資料庫進行比對，並與其它已知的ITS 基因序列以Neighbor-Joining method、 Maximum-likelihood method 及Maximum-parsimony method等方法建構樹狀圖，結果顯示Scenedesmus AELCNU-JDB1 008的ITS rDNA基因序列(ITS1、5.8S、ITS2)，大小約514bp，確認為genus Desmodesmus。Scenedesmus AELCNU-JDB1 009的ITS rDNA (ITS1、5.8S、ITS2) 基因序列大小約488bp，確認其為genus Scenedesmus (柵藻屬)。Chlorella AELCNU-JDB1 010，從其ITS (ITS1、5.8S、ITS2)基因序列大小約732bp，只能確定為Family Chlorellaceae (小球藻科)。本研究結果亦顯示:微藻生物多樣性的研究，仍是須依賴傳統的形態特徵做為分類的基礎。DNA分析只是輔助工具，目前尚無法取代傳統微藻生物多樣性的研究方式。 Investigations microalgal taxonomy was based almost exclusively on morphological features under microscope until recent years, when molecular phylogenetic investigations were started.
Previous studies on three green algae by 18S rDNA partial sequences were not easy to identify to species level. Here we sequenced and compared the ITS1 and ITS2 of three green algal species taking from AELCNU (Algal ecological laboratory, Chia-Nan University), including Scenedesmus AELCNU-JDB1 008 and Scenedesmus AELCNU-JDB1 009 and Chlorella AELCNU-STR 010. Algae were cultured in f/2 medium. The cells in logarithmic growth phase were taken for ITS rDNA analysis. The results of ITS rDNA sequences were compared with NCBI data base. Phylogenetic trees were constructed using other known green algae ITS DNA sequences, and tree topologies were obtained by Neighbor-Joining method, Maximum-likelihood method and Maximum-parsimony method. There are about 514bp ITS rDNA (ITS1、5.8S、ITS2) gene sequences of Scenedesmus AELCNU-JDB1 008, 488bp ITS rDNA of Scenedesmus AELCNU-JDB1 009 and 732bp of Chlorella AELCNU-JDB1 010. We defined the Scenedesmus AELCNU-JDB1 008 is genus Desmodesmus, Scenedesmus AELCNU-JDB1 009 is genus Scenedesmus and Chlorella AELCNU-JDB1 010 is Family Chlorellaceae. The results demonstrated that traditional taxonomic methods are still useful for microalgal biodiversity, DNA analysis is only an auxiliary tool.
