Studies of conidial anatomy and conidiogenesis inSporoschisma nigroseptatumusing light and electron microscopy

摘要

The results of an ultrastructural study of the conidial anatomy and conidiogenesis inSporoschisma nigroseptatumare presented. The development of the conidial chain involves endogenous conidial ontogeny, apical wall-building, and retrogressive conidial delimitation followed by cessation of apical wall-building, then replacement ring wall-building of additional retrogressively delimited conidia, and extrusion of the true conidial chain through the terminal aperture of the conidiogenous cell. Maturation of conidia involves deposition of two inner wall layers and formation of five distosepta. Conidial chains secede schizolytically. No proliferation of the conidiogenous cell occurs and the conidium is delimited by a cross wall that is discontinuous with the periclinal wall. Each conidium has polar plug-and-socket-like structures that are interlocked between adjacent conidia along the conidial chain. Similar plug-and-socket-like structures are also seen in otherSporoschismaspecies. The taxonomy ofChalarais also briefly discussed with reference to patterns of conidial wall-building.Key words:Chalara, conidial chain, conidial ontogeny, ultrastructures.