Conidial development in selected ambrosial species of the genus Raffaelea

Conidiogenesis of the type species and two additional species of the genus Raffaelea Arx & Hennebert are described. In contrast to previous conclusions based on light microscopy that indicate sympodial production of the conidia, we found that conidium development was by annellidic percurrent proliferation in the type species Raffaelea ambrosiae, as well as in Raffaelea arxii and Raffaelea albimanens. Consequently, this mode of conidium development is similar to the conidiogenesis of anamorphs within the Ophiostomatales, but distinguished by sporodochia formed within the genus Raffaelea. These findings reduce the differences between Raffaelea and other anamorphs with annellidic percurrent proliferation of the conidiogenous cells within the Ophiostomatales to different conidiomata and conidiophores, and they support previous reports of the close phylogenetic relationship between Raffaelea and Ophiostoma.