FIG. 2.

Dendrogram based on the number of differences in a total of 75 scored RAPD markers among the three biotypes of T. harzianum and T. atroviride. Numbers on the dendrogram refer to PSU accession numbers for the isolates. No genetic variation was observed among isolates within the biotype 2 and 4 clusters (Th2 and Th4). The biotype 1 and 2 and T. atroviride (T. a) clusters each contained eight isolates from Europe, whereas the biotype 4 cluster contained 58 isolates from Pennsylvania and three tester isolates from Canada.