NEW INSIGHTS INTO POPULATION-STRUCTURE OF BEAUVERIA-BASSIANA WITH REGARD TO VEGETATIVE COMPATIBILITY GROUPS AND TELOMERIC RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS

The occurrence of vegetative compatibility groups (VCGs) in Beauveria has been examined by analyzing compatible and incompatible reactions b etween complementary nitrate non-utilizing mutants. Complementary muta nts (nia, and cnx) generated from 25 isolates from different host and insect origins were paired in all combinations revealing 14 different VCGs. Strains isolated from European corn borer in different European countries formed a distinct subspecific group whereas Sitona weevil is olates collected in the same country were found in different VCGs. A h igh level of polymorphism was detected by fingerprinting through South ern blot hybridization with a telomeric probe. Examination of DNA vari ations among isolates belonging to different VCGs suggested that varia tions in telomeric patterns was correlated with VCG groupings; these r esults underlined the existence of genetic limits to gene flow that wo uld result in genetically diverse subpopulations.