Genetic Variation in Heterobasidion annosum Detected with M13 Fingerprinting and Ribosomal DNA Probes

Karlsson, J.-O. 1994. Genetic variation in Heterobasidion annosum detected with M13 fingerprinting and ribosomal DNA probes. Experimental Mycology 18, 48-56. Mitochondrial and nuclear DNA diversity were analyzed in 54 strains of the forest pathogen Heterobasidion annosum (Fr.) Bref. from Northern Europe. Restriction-fragment-length polymorphisms were detected with three different probes on Southern blots of DNA restricted with Hae III. Intersterility groups were clearly differentiated based on the UPGMA clustering of M13 minisatellite bands, and strains with the same geographic origin tended to form clusters. Average band share values were 0.80 and 0.68 within S- and P-groups, respectively, and 0.49 between groups. When the ribosomal mitochondrial ML 5-8 region was used as a probe the two types of patterns observed were in accordance with the results of the mating tests and the UPGMA clustering of fingerprints. No variability was detected in ribosomal nuclear ITS 1-4 region.