CONIDIUM DEVELOPMENT IN THE HYALORHINOCLADIELLA ANAMORPH OF OPHIOSTOMA IPS

The anamorph of Ophiostoma ips has been suggested to have both sympodi al and phialidic conidium development. The phialidic form has conseque ntly been referred to as Acremonium-like and the sympodial form as a s pecies of Hyalorhinocladiella. The aim of this study was to determine the mode of conidium development and consequently the identity of the anamorph of Ophiostoma ips. Light microscopy clearly indicated that sy mpodial proliferation occurred during conidiogenesis. However, using s canning electron microscopy, conidiogenous cells were found to be anne llidic. This was confirmed using transmission electron microscopy wher e distinct annellations could be distinguished on conidiogenous cells. We conclude that conidium development in the anamorph of Ophiostoma i ps is annellidic and that an illusion of sympodial conidium developmen t results from delayed secession of conidia. Hyalorhinocladiella could therefore be an acceptable genus for this fungus, although its circum scription would require modification.