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

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

Variation in Septocyta ruborum and its potential for biological control of European blackberry

The fungus Septocyta ruborum causes a destructive necrosis of floricanes in blackberry (Rubus fruticosus) in Europe and is a potential candidate for biological control in Australia. Over 100 accessions of S. ruborum from Europe were analysed for variation in pathogenicity and virulence. Virulence varied among accessions within R. fruticosus 'species'. Accessions screened for genetic diversity using (internal transcribed spacer (ITS) sequencing and RAPD (random amplification of polymorphic DNA) yielded identical ITS sequences, but three of 120 RAPD primers showed high levels of polymorphism. Accessions clustered into five main groups, but these were not related exclusively to virulence or geography. Some accessions from northern Europe and one accession from Hungary clustered apart from the main group. The large amount of polymorphism in both virulence and genetics suggests that S. ruborum reproduces sexually or that it has subdivided into many races. The large genetic variation offers considerable potential for selection of host-specific forms, an advantage in biological control

Energy management in Africa

Published in association with African Energy Policy Research Network - AFREPRE