Authors:
Nachaat Sakr
Volume 29, Issue 3;
Pages: 236-243; 2023
ISSN: 2069-0053 (print), Agroprint;
ISSN (online): 2068-9551
Fusarium pathogens are among the grave small-grain cereal species with a high toxicity capacity. In global agriculture, contamination of cereal grains with toxic metabolites of Fusarium is one of the especially crucial problems. Effective work with Fusarium cultures necessities their safe long-term preservation, but limited reports have appeared on maintenance. The present research assessed the preservation of Fusarium spp. (6 F. solani, 5 F. culmorum, 4 F. verticillioides and one F. equiseti) by freezing. Potato dextrose agar (PDA) dishes containing grown mycelia were transferred from 22 ± 1ºC directly to a mechanical freezer at -16°C and stored in May 2015. Viability was evaluated after at 6, 12, 18, 24, 30, 36, 60, 96 months of preservation, through the revival of isolates on PDA and analysis of micro- and macro-morphological characters and contamination by other microorganisms. 100% viability was observed and efficiency did not change with individual cultures, in spite of preservation conditions or time duration. More significantly, freezing did maintain Fusarium cultures irrespective of their pathogenic background, showing that this method preserves successfully Fusarium species varying in pathogenicity. Preservation at -16°C did not modify the morphological stability during storage durations and contamination by bacteria or other fungi were not observed after 8 years of storage. This reports exhibits for the first time that the procedure for storing Fusarium cultures by freezing at -16°C is a simple and inexpensive technique