Restriction fragment length polymorphism (RFLP) of mitochondrial DNA (
mtDNA) was examined in 32 isolates of Phialophora verrucosa (eight iso
lates from Japan, 10 from China, four from the USA, six from Venezuela
and four from Colombia) and in three of Phialophora americana using f
ive restriction enzymes. P. verrucosa isolates were divided into 10 mt
DNA types based on RFLP patterns. Phylogeny constructed on sequence di
vergence of mtDNA indicated that P. verrucosa is a single species and
isolates are clustered into three groups. Japan and the USA contained
Group A and Group B isolates, China Group B isolates and South America
Group B and Group C isolates. RFLP patterns of P. americana mtDNA wer
e identical to those of Type 1 or Type 4 of P. verrucosa mtDNA, sugges
ting that both are identical. RFLP patterns of P. verrucosa were disti
nct from those of other dematiaceous fungi including Exophiala jeansel
mei, E. moniliae, E, dermatitidis, E, spinifera, Cladophialophora loph
ora (Cladosporium) carrionii, Fonseceae pedrosoi, and Hortaea wernecki
i. These results indicate that RFLP analysis of mtDNA is a useful meth
od. for the identification, taxonomy, typing, epidemiology and phyloge
ny of P. verrucosa.