Date of Award


Degree Type


University or Center

Atlanta University (AU)


School of Arts and Sciences

Degree Name




First Advisor

Dr. Lafayette Frederick


Isolates of Ceratocystis ulmi, the etiological agent of the Dutch elm disease were studied electrophoretically in order to ascertain the extent to which their alpha esterase patterns and general protein profiles differed. Isolates studied were obtained from symptomatic trees of Ulmus americana and U. alata in the Atlanta area. In culture, these isolates exhibit substantial variations in mycelial characteristics. Pathogenic records of disease responses in the hosts from which the isolates were obtained suggested that they differed in aggressiveness. Electrophoretic analysis of these organisms indicate that they also vary substantially in their protein and isozyme patterns. Since these profiles are of a nature that are presumed to be under genetic regulation, the isolates studied appeared to represent distinct strains of C. ulmi. Furthermore, on account of the substantial differences exhibited by the isolates, it appears as if the Atlanta area has been more than one strain of the Dutch elm disease fungus.

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