Electron microscopy of zoospores and cysts of Phytophthora palmivora: Morphology and surface texture

Summary Scanning electron microscopy and transmission electron microscopy (carbon replicas) confirm the existence of a deep longitudinal groove on one side of the pyriform body of the zoospores of Phytophthora palmivora. Upon encystment the cell rounds off but the groove may be temporarily retained as a depression on the cyst surface. The carbon replicas revealed significant differences in outer surface texture: the zoospore surface is finely granular whereas the outer surface of both young and mature cysts are distinctly microfibrillar with only occasional patches of amorphous material.