A COMPARISON OF THE NUCLEOTIDE-SEQUENCE OF THE CERATO-ULMIN GENE AND THE RDNA ITS BETWEEN AGGRESSIVE AND NON AGGRESSIVE ISOLATES OF OPHIOSTOMA-ULMI SENSU-LATO, THE CAUSAL AGENT OF DUTCH ELM DISEASE

Little genetic information exists comparing aggressive and non-aggress ive isolates of the causal agent of Dutch elm disease, Ophiostoma ulmi . Two genetic elements were compared between the subgroups. The cerato -ulmin cu gene product has been associated with disease symptoms. Nucl eotide-sequence analysis of cu and the internal transcribed spacer (IT S) region of the rDNA were made from three aggressive and three non-ag gressive isolates of the pathogen. Our results suggested uniformity wi thin, and unique differences between, subgroups. Differences were dete cted for cu in the promoter, coding, and transcription termination reg ions. Sequence data for the ITS clearly distinguish the subgroups.