A Light and Electron Microscope Survey of Algal Cell Walls. II, Chlorophyceae

Author Institution: Department of Botany, University of South FloridaUnder the light and electron microscopes, the structure of the cell walls of members of the 11 orders in the Class Chlorophyceae, Division Chlorophyta, were examined. With regard to the microfibrillar component of the cell walls, five types of wall structure were distinguished: (A) an apparent lack of a micro fibrillar component (Volvocales, Dasycladales, and some members of the Siphonales), (B) the microfibrils are arranged in a reticulate pattern (Tetrasporales, Schizogoniales), (C) the microfibrils are oriented in an axial direction (Ulotrichales, Oedogoniales, Zygnematales, and some members of the Siphonales), (D) the microfibrils are parallel to one another and arranged in lamellae (Ulvales), and (E) the microfibrils are parallel to one another, arranged in lamellae, and at right angles to the microfibrils in the lamellae above and below forming the crossfibrillar pattern (Cladophorales, Siphonocladales). Members of the Ulvales were found to have a cell wall similar to that of the brown algae while a member of the Schizogoniales, Prasiola, was found to have a cell wall similar to that of the red algae. A discussion of the taxonomic implications of cell wall structure is included