Viability, Pathogenicity and Fungicide Sensitivity of Botrytis cinerea Isolates After Storage for up to 6 Years

Abstract

Botrytis cinerea causes pre- and postharvest diseases in several crops. Effective methods for long-term storage to maintain its viability and characteristics are necessary. This study evaluated the viability and pathogenicity of 125 isolates collected in 2017 and stored for 2 and 6 years using four methods: Castellani (water, room temperature), filter paper discs with silica gel (−18°C), glycerol (−18°C), and filter paper strips (−18°C). It also assessed changes in resistance to azoxystrobin, boscalid, fluazinam, and procymidone in 20 isolates. Viability was highest with silica gel and filter paper discs (average 71.2% and 60.0%, respectively), and more than 90% of the viable isolates remained pathogenic on strawberry fruit, except for those stored using the Castellani and glycerol methods after 6 years. Resistance to azoxystrobin and boscalid was stable, while the number of resistant isolates declined by 25% and 30% for fluazinam and procymidone, respectively. Overall, the method utilising silica gel with filter paper discs proved to be the most effective storage method for B. cinerea isolates, and the results confirmed the instability of resistance to fluazinam and procymidone.