Presence of a 20 bp insertion/deletion in the ITS1 region of Verticillium lecanii

Polymerase chain reaction (PCR) amplification of the complete ribosomal RNA internally transcribed spacer (ITS) region of 36 isolates of Verticillium lecanii and related species gave a single 620 bp product in 31 isolates. Fi ve isolates received as V. lecanii, however, gave a single product of 600 b p. Restriction fragment analysis of the PCR products from all isolates gave consistent patterns for the 31 isolates with a 620 bp product. The five is olates with the 600 bp product showed only minor discrepancies to these, ge nerally related to the size of only one restriction fragment. The total ITS region was sequenced from 10 typical 620 bp isolates and one 600 bp isolat e. Sequence variation between the isolates varied from 0 to 14.5%, and the 20 bp size discrepancy was found to relate to an insertion or deletion in t he centre of the ITS1 region.