国产球盖蕨科植物管状分子的比较研究

利用扫描电镜观察了国产球盖蕨科10种植物,鳞毛蕨科6种植物的管状分子,结果显示:它们的管状分子端壁和侧壁的形态及结构分别相同,且侧壁具有穿孔板。它们具有4种类型的管状分子:(1)梯状穿孔板,无穿孔板的二型性现象;(2)梯状穿孔板,具有二型性现象;(3)梯状-网状混合穿孔板;(4)大孔状穿孔板。穿孔板仅存在于端壁的管状分子为导管分子,而端壁和侧壁形态、结构相似,有或无穿孔板的管状分子为管胞,蕨类植物中的管状分子主要为管胞,这与传统观点不同。管状分子的形态特征表明:球盖蕨科是鳞毛蕨群的成员,但不是原始成员,可能属于其中较为进化的类群,与鳞毛蕨科有许多共同特征,但仍存在较大差异,所以将其作为独立的科是合理的,推测球盖蕨科中的鱼鳞蕨属是比较进化的属,柄盖蕨属相对原始,红腺蕨属的系统位置应介于二者之间。

Comparative Study of Tracheary Elements in Peranemaceae from China

Tracheary elements of 10 speices of Peranemaceae and 6 species of Dryopteridaceae from China were examined by scanning electron microscopy(SEM).The results indicate that the end walls have the same morphological characteristics and structure as the lateral walls.The lateral walls have perforation plates.The tracheary elements could also be divided into 4 types:(1)scalariform without dimorphic width perforation;(2)Scalariform with perforation pit dimorphism;(3)Reticulate-scalariform plates;(4)Coarse-pored perforation plates.Different from the traditional ideas,the tracheary elements which have perforation plates only on end walls are vessel elements,tracheids have end walls and lateral walls with the same morphological characteristics or structure,with perforation plates or not.The tracheary elements in ferns are tracheids.The feature of tracheary elements indicates that:the Peranemaceae is a member of the Dryopteridaceae group,but not a original one,which may be a evolutionary member.The Peranemaceae and the Dryopteridaceae have many similar characteristics,but there are still a lot of differences between them.So it is reasonable to consider the Peranemaceae as an independent family.Acrophorus Presl might be more advanced,Peranema D.Don might occupy a primitive position relatively,and the systematic position of Diacalpe Bl might be between Acrophorus Presl and Peranema D.Don.