黄群藻目分类系统述评及主要分类特征的评价

黄群藻目Synurales是主要根据光合色素和亚显微结构特征建立的一个目，也是淡水金藻中较大的一个目，包括约160种。该目的植物体为自由运动的单细胞或群体，细胞的表质上覆盖许多硅质的鳞片，以覆瓦状、甲胄状排列或自由附着于表质上，鳞片具刺毛或无，具1条或2条不等长鞭毛。黄群藻目植物区别于其它金藻植物的主要特征为，它们的色素体仅含有叶绿素C1，鞭毛基部平行排列，并且形成硅质鳞片的硅质沉积孢囊与叶绿体外膜相连。自建立至今，该目的分类系统几经变化。本文综述了黄群藻目分类系统的研究进展，并对其主要形态特征的分类价值进行了分析。

Change and Development of the Classification Systems of Synurales(Chrysophyta) and Evaluation of Its Main Characteristics

Synurales,which was built mainly based on the photosynthetic pigment and uhrastructural characteristics,is a large order of fresh-water golden algae. At present,the Synurales contains about 160 species. The plant of this order includes colored monads or some colonies, with the cells covered with silica scales arranging regularly as imbricate or armor shape,or freely. Some scales bear bristles and some do not. The cell bears one or two unequal flagella in length. Compared with the other orders of freshwater golden algae, the main differences of the Synurales are that 1) their plastids only contain chlorophyll cl ;2) the bases of flagella arrange parallel ;3) and their silica deposition vesicles conjunct with the outer chloroplast membrane. To date, the classification system of this order has been modified for several times. In this pa-per, the advances of classification system of Synurales have been reviewed and the taxanomic values of the main characteristics used in classi-fication have been analyzed and assessed.