Growth, Survival and Spore Formation of the Pathogenic Aquatic Oomycete Aphanomyces astaci and Fungus Fusarium avenaceum Are Inhibited by Zanthoxylum rhoifolium Bark Extracts In Vitro

Abstract

This study aimed to evaluate the in vitro activity of Zanthoxylum rhoifolium bark (Zr-b) extracts against pathogenic aquatic oomycete/fungal isolates that cause different diseases in native European crayfish resulting in an elevated mortality rate and severe economic repercussions. n-hexane, chloroform, chloroform–methanol (9:1) and methanol extracts of Zr-b were used to evaluate the antifungal activity against the strain UEF88662 of Aphanomyces astaci (oomycete) and the strain SMM2 of Fusarium avenaceum (fungus). The anti-oomycete and antifungal activity was quantitatively evaluated by growth, survival and sporulation microbiological assays. The extracts tested demonstrated a dose-dependent inhibitory effect on oomycete and fungal growth and survival, as well as on the production of oomycete and fungal spores. This work presents alternatives for the treatment and prevention of the spreading of Aphanomyces astaci and Fusarium avenaceum, the etiological agents of the diseases crayfish plague and brown spot disease, respectively. The antifungal properties of Zanthoxylum rhoifolium bark extracts warrant further research on their use in the prevention and treatment of both oomycete and fungal diseases. The antifungal properties of Zanthoxylum rhoifolium bark extracts, shown in vitro, indicate the possibility of their use in new therapeutic and prophylactic strategies, providing perspectives for the design of in vivo studies.