囊裸藻属与陀螺藻属囊壳微细结构及元素组成比较

对采自自然水体中囊裸藻属(Trachelomonas)的8种和陀螺藻属(Strombomonas)的两种藻类的囊壳微细结构和元素组成进行了比较分析，并探讨了这两个属的系统演化关系。结果表明：组成囊壳的矿质元素主要是铁和硅，在陀螺藻和表面粗糙的囊裸藻中，硅的含量较高，铁的含量相对较低；在大多数囊裸藻中，尤其是表面致密、光滑的种类中，铁的含量较高，硅的含量较低，矿质元素的组成与囊壳的颜色无直接关系。建议将陀螺藻属(Strombomonas)撤消，原陀螺藻属的种作为囊裸藻属(Trachelomonas)中的一个种组(Group)，它们是裸藻科中最原始的具囊壳的类群。

Comparative Studies on the Fine Structure and Elemental Composition of Envelopes of Trachelomonas and Strombomonas (Euglenophyta)

Fine structure and elemental composition of envelopes of 10 taxa of Trachelomonas and Strombomonas from natural freshwater bodies in China were studied and phylogeny of both genera were discussed. The results indicate that iron (Fe) and silicon (Si) are the primary mineral elements of the envelopes. Composition of mineral elements was uncorrelated with envelope color, however, it was highly correlated with the microarchitecture of the envelopes. Content of Si was higher than that of Fe in all species of Strombomonas and some species of Trachelomonas with rough surface. In most species of Trachelomonas , especially those with dense and smoothy surface, content of Fe was higher than that of Si. Based on the above results, we propose to assign those species of Strombomonas into Trachelomonas and consider them as a group of the latter. These species were the most primitive among the group with envelopes in Euglenaceae.