ETHYLENE PRODUCTION BY BOTRYTIS-CINEREA

Ethylene was produced when isolates of the postharvest pathogen Botryt is cinerea Pers.: Fr., derived from fruit of strawberry, blueberry and kiwifruit and leaves of grape and camellia, were grown on a modified Pratt's medium containing 35 mM methionine in shaken or static culture s at 22 degrees C in the dark. Cultures grown on basal media containin g glutamate or alpha-ketoglutarate produced no more ethylene than cont rols. Optimum growth occurred at pH 3.5 and 4.5 for shake and static c ultures, respectively. When B. cinerea was grown in a methionine-amend ed basal medium, maximum production of ethylene occurred after 3-4 day s of incubation. However, maximum ethylene production per unit dry wt of mycelium (780 mu l/g/h) occurred within 48 h of inoculation, after which it declined. That high ethylene production occurs with such smal l amounts of mycelia suggests a possible role for fungal produced ethy lene in B. cinerea pathogenesis of sensitive fruit such as kiwifruit. (C) 1997 Elsevier Science B.V.