Verrucostoma, a new genus in the Bionectriaceae from the Bonin Islands, Japan

Abstract

Verrucostoma freycinetiae gen. et sp. nov. is described and illustrated from specimens on dead leaves of Freycinetia boninensis (Pandanaceae) collected in Hahajima, Bonin (Ogasawara) Islands, Japan. The genus is characterized by pale orange perithecia with protuberances around the perithecial apex, no color change in 3% potassium hydroxide and lactic acid, unitunicate asci, spinulose ascospores and an Acremonium-like anamorph. Morphological characters were compared with other genera in the Bionectriaceae and Nectriaceae (Hypocreales). Verrucostoma is morphologically similar to Bionectria (Bionectriaceae) from which it differs in the formation of conspicuous protuberances around the perithecial apex and the Acremonium-like anamorph. Moreover molecular analyses of Verrucostoma and other members of the Bionectriaceae and Nectriaceae based on α-actin, large subunit nuclear ribosomal DNA and RNA polymerase II subunit 1 sequences support the conclusions based on morphological data. Our results confirm that V. freycinetiae is distinct from other genera among the Nectria-like fungi and represents a new genus belonging to the Bionectriaceae.

• Ascomycota
• Freycinetia
• Hypocreales
• molecular systematics
• Pandanaceae

This study was supported in part by the United States National Science Foundation (NSF) PEET grant DEB-0731510 Monographic studies in the Nectriaceae, Hypocreales: Nectria, Cosmospora and Neonectria to University of Maryland (PI: P. Chaverri, A.Y. Rossman, G.J. Samuels). We sincerely thank Andrew M. Minnis for providing nomenclatural advice and Cesar Herrera for assistance in depositing cultures.