SEPTAL PORE STRUCTURE IN TRICHODERMA SATURNISPORUM

Electron microscopic observations of a previously undescribed ascomycetous septal pore structure are presented and discussed. Hyphal septa and septa at the base of phialides in the hyphomycete, Trichoderma saturnisporum Hammill, developed a membrane-bounded, electron-opaque septal pore body which was fine-structurally similar to Woronin bodies. Within a septal pore body, several electron-transparent layers appeared to develop centripetally from the septal pore rim. The number of layers observed varied from two to about five, with lower numbers being more frequently observed. The electron-transparent layers perhaps functioned as a vinculum, binding the septal pore body in place. Questions about the origin and function of septal pore bodies are discussed.