The connection between Abrothallus and its anamorph state Vouauxiomyces established by Denaturing Gradient Gel Electrophoresis (DGGE)

The relatively infrequent co-occurrence of different life phases in some groups of pleomorphic fungi has made the establishment of a clear relationship between the sexual (perfect or teleomorphic) and its asexual (imperfect or anamorphic) stages difficult. Fungal cultures, chemosystematic markers and, in recent years, DNA sequences, have been routinely used in the settlement of full life cycles of pleomorphic fungi. The case of the lichenicolous genus Abrothallus de Not. and its anamorph Vouauxiomyces Dyko & D. Hawkws. is representative of such a lack of conclusive proofs to connect sexual and asexual phases. The genus Vouauxiomyces was introduced by Hawksworth & Dyko (1979) for coelomycetous fungi characterized by having immersed to erumpent pycnidia and clavate to pyriform-shaped holoblastic hyaline conidia with a truncated base. The type species V. truncatus (B. de Lesd.) Dyko & D. Hawksw. (syn. Phoma truncata B. de Lesd.) grows on the thallus of Flavoparmelia caperata (L.) Hale and represents a candidate anamorph of A. microspermus Tul. Hawksworth & Dyko (1979) did not mention the anamorph-teleomorph connection of Abrothallus and Vouauxiomyces in their description. However, the putative evidence of this relationship, based on frequent co-occurrence of ascomata of Abrothallus and Vouauxiomyces–type conidiomata on the same lichen thallus, was already noted in one of the earliest papers about lichenicolous fungi (Tulasne 1852). This observation-based connection was accepted and illustrated by later authors (Lindsay 1857; Kotte 1909; Schaechtelin & Werner 1927; Keissler 1929; Hawksworth 1981) without additional confirmation. In his treatment of lichenicolous coelomycetes, Hawksworth (1981) described the new species V. santessonii D. Hawksw. (on Platismatia glauca (L.) W. L. Culb. & C. F. Culb. and Parmelia saxatilis (L.) Ach. ) and recombined Phoma ramalinae Nordin (Nordin 1964) into V. ramalinae (Nordin) D. Hawksw. Up until now, five species of Vouauxiomyces have been described (Index Fungorum http:// www.indexfungorum.org, consulted on 20th September 2010). Besides the cited species, V. brattii S. Y Kondr. and V. granulatae Wedin (both growing on Pseudocyphellaria species) have already been published (Wedin 1994; Kondratyuk 1996). Out of the five species, V. bratti is the only one for which a putative teleomorph has not yet been defined (Kondratyuk 1996). During the course of our studies on the genus Abrothallus, we have observed anamorph states accompanying most of the studied specimens (Suija 2006; Suija et al. 2011). As there has been no success in preparing cultures of Abrothallus and Vouauxiomyces from ascospores or conidia, respectively (Crittenden et al. 1995; S. PérezOrtega, pers. obs.), the relationships between Abrothallus and Vouaxiomyces have always been assessed by co-occurrence. Here we report definitive proof of the connection between anamorphic Vouauxiomyces and teleomorphic Abrothallus using the fingerprinting technique of Denaturing Gradient Gel Electrophoresis (DGGE; Muyzer et al. 1993). We analyzed the anamorph and teleomorph states of Abrothallus growing on both Xanthoparmelia protomatrae (Gyeln.) Hale and Punctelia jeckeri (Roum.) Kalb.