Infection processes of Septocyta ruborum, a coelomycetous fungus with potential for biological control of European Blackberry in Australia

Abstract

The coelomycetous stem canker pathogen Septocyta ruborum causes stem die-back of European blackberry (Rubus fruticosus agg.). The fungus infects its host by penetrating stomata, stem wounds and possibly crevices associated with hair bases. Invasion of vascular bundles by hyphae disrupted internal transportation processes and appears to be the main mechanism for stem decline. Multiple cutting of the stem surface increased infection in whole plants, but the epidermis was vital to infection. Host-testing and field evaluation of S. ruborum as a potential biological control agent for European blackberry will involve histological evidence of infection to assess the risks it poses to non-target plant species