Species level identification of conifer associated Ceratocystis sapstain fungi by PCR-RFLP on a β-tubulin gene fragment

The genus Ceratocystis includes several morphologically similar species commonly found as agents of sapstain in coniferous trees. In this paper we describe a simple and reliable polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique that aids in the identification and differentiation of these fungi. PCR was used to amplify a 1.3-kb fragment of the beta-tubulin gene from C. coerulescens, C. pinicola, C. douglassi, C. resinifiera, C. rufipenni, C. polonica and C. adiposa. The PCR amplicon from representative isolates was sequenced. This information was utilized to select restriction enzymes that generated species-specific RFLP patterns. This approach was tested on our collection of over 200 Ceratocystis isolates and identified the fungi with a high level of confidence, reducing the time needed to identify these species by classical methods. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.