Genetic variation in Fusarium merismoides preserved by two different methods

Restriction-enzyme digestion followed by agarose gel electrophoresis demonstrated differences between the purified DNA from Fusarium merismoides which had been held in a culture collection in liquid N2 and that from soil-stored samples of the same fungus. Extended incubation (3 to 4 weeks) of a culture resulted in the appearance of an extra band, sensitive to EcoRI, which could correspond to a previously reported plasmid and may, therefore, be associated with senescence. The results emphasize the importance of using cultures of a standard age for genetic analysis and demonstrate the potential of microbial preservation and storage techniques to affect the fungal genome.