COMPARISON OF RAPD TECHNIQUE AND SOMATIC INCOMPATIBILITY TESTS FOR THE IDENTIFICATION OF PHLEBIOPSIS-GIGANTEA STRAINS

Somatic incompatibility assays and random amplified polymorphic DNA (R APD) analysis were assessed and compared for use in monitoring the sur vival of introduced strains of Phlebiopsis gigantea, a fungal biocontr ol agent used against Heterobasidion annosum root rot. Overall there w as concordance between the two methods. All incompatible strains exhib ited different RAPD profiles whilst compatible ones, with two exceptio ns, had the same RAPD profile. Somatic incompatibility tests and RAPD profiles generated by three primers, from which 11 markers were retain ed, could distinguish field-tested strains from among 60 strains from a population collected in Quebec and Ontario. Furthermore, both method s allowed us to clearly demonstrate the presence of inoculated strains 1 year after treatment. The combined use of these techniques provides a valuable tool for discriminating between different P. gigantea stra ins and conducting epidemiological studies.