Storage of stock cultures of filamentous fungi at -80 degrees C: effects of different freezing-thawing methods.

Freezing and storage at -80 degrees C has been applied to the preservation of nonsporulated filamentous fungi Phytophthora, Pythium, Sclerotinia and Rhizoctonia, and the results are presented. We had tested different methods of freezing and thawing, finding that the best results were obtained pre-cooling at 4 degrees C during 1 hour followed by freezing at -80 degrees C. The best thawing method was achieved at 37 degrees C. The technique was found to be simple and reliable for the culture collections labours of fungi maintenance.