Differentiation of mitochondrial subgroups in the Verticillium lecanii species complex

Presumptive mitochondrial DNA (mtDNA) restriction fragment length polymorph isms (RFLPs) were obtained from 54 fungal isolates identified as Verticilli um lecanii, V. psalliotae or 'V. lecanii-like'. Analysis of the mtDNA RFLPs showed 20 different patterns, indicating considerable genetic variation wi thin the V. lecanii species complex. There was no direct correlation betwee n host and mtDNA pattern, or between mtDNA patterns and previously describe d isoenzyme-defined specific groups. Isolates from tropical and subtropical areas showed considerable variation in genotypes, while isolates from temp erate regions appeared less variable.