Use of randomly amplified polymorphic DNA markers as a tool to study variation in lichen-forming fungi

A protocol is described to enable the production of reliable genetic finger prints of lichen-forming fungi using randomly amplified polymorphic DNA (RA PD) markers. Key features of the method are the use of mycobiont DNA extrac ted from axenic cultures by a phenol-chloroform procedure, and PCR amplific ation using DyNAzyme Tr DNA polymerase. RAPD-PCR fingerprints of Graphis sc ripta, G. elegans and Phaeographis dendritica were successfully generated u sing this protocol and individual isolates could be identified on the basis of differences in banding patterns produced. DNA extracted from whole thal li of G. scripta was also subjected to RAPD-PCR but the fingerprints produc ed differed from those given by axenic cultures of the mycobiont. Therefore difficulties of interpretation may arise when whole thalli are used in RAP D analysis. (C) 1999 The British Lichen Society.