Analysis of Polygalacturonase Enzyme Production in Isolates of Botrytis cinerea Sensitive to Different Fungicides Used in Vineyards

Abstract

Reduction of mycelial growth and spore germination of Botrytis cinerea, the causal agent of grey mould, are common criteria to determine the sensitivity of this fungus to fungicides. In this article, the influence of nine different fungicides on polygalacturonase (PG) activity and mycelial dry weight (MDW) was analysed on culture filtrates from B. cinerea, obtained from grapes. All fungicides except triadimenol and tebuconazole inhibited MDW of isolates <50%. Cyprodinil + fludioxonil, myclobutanil and imazalil inhibited PG activity more than 50%. Fenhexamid had a lower inhibitory effect (<50%) on PG activity. Procymidone and pyrimethanil induced both PG activity and isoenzyme banding profile of isolates sensitive to these fungicides. This study provides a new additional tool for determining sensitivity to fungicides and monitoring the effect of fungicide resistance management policies.