Inhibitory Effect of Moriniafungin Produced by Setosphaeria rostrata F3736 on the Development of Rhizopus Rot

Abstract

Rhizopus rot is a serious postharvest disease of various crops caused by Rhizopus spp. and controlled mainly by synthetic fungicides. We detected the antifungal activity of a culture extract of Setosphaeria rostrata F3736 against Rhizopus oryzae. The active ingredient was identified as moriniafungin, a known sordarin derivative, which showed minimum inhibitory concentrations of 1-8 mu g/ml against Colletotrichum spp. and 0.03-0.13 mu g/ml against Rhizopus spp. in vitro. Moriniafungin showed protective control efficacies against Rhizopus rot on apple and peach fruits. Treatment with 25 mu g/ ml moriniafungin delimited the lesion diameter significantly by 100% on R oryzae-inoculated apple fruits compared with the non-treated control. Treatment with 0.04 mu g/ml of moriniafungin reduced the lesion diameter significantly by 56.45%, and treatment with higher concentrations of 0.2-25 mu g/ml reduced the lesion diameter by 70-90% on Rhizopus stolonifer var. stolonifer-inoculated peach fruit. These results suggest moriniafungin has potential as a control agent of postharvest diseases caused by Rhizopus spp.