Abstract

                                The use of certain drugs particularly antibiotics against bacteria and certain insecticides against insects have resulted in the appearance of resistant strains, creating a new problem in the treatment of diseases. Unlike insects so far fungi do not seem to have reacted to fungicides in such a spectacular manner although a downy mildew resistance does occur against certain chemicals (Taylor 1953). Fungi have been reported to educate them- selves to increasing concentrations of toxic substances (Wilson 1947 and Hirschhorn and Munneck 1950). In some cases mutation clearly accounted for what could have been considered adaptation while in, other cases visible mutation did not account for such results. The present work was undertaken to study the adaptation of Botryodiplodia theobromae to copper sulphate, mercuric chloride and zinc sulphate.

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