Scanning electron microscopy of perithecial development in a species of Phyllactinia on oak

Abstract

A species of Phyllactinia on oak was examined by scanning electron microscopy. The naturally dried fungus was minimally manipulated in preparation for study. Development was followed by examining various stages from initial to mature perithecium. Immature perithecial appendages were found to be less rigid than those which had matured. The sticky apical mucilage droplet on the maturing perithecium was observed, but the penicillate cells that form the droplet were not easily seen. As the appendages dried they lifted the perithecium off the surrounding surface. Some perithecia were found that had overturned and adhered to the hyphae-covered leaf by means of the mucilage droplet. This study has resulted in visualization of Phyllactinia surface structure in more detail than heretofore reported. Other plant pathogenic fungi, especially those producing naturally dry mature fruiting bodies, should be amenable to study by this method.