Eucalyptus leaf diseases associated with Neofusicoccum spp. in North Africa

Abstract

This study represents the first survey reporting the occurrence of Neofusicoccum species associated with Eucalyptus foliar diseases in semi-arid areas in North African countries. Based on morphological features and phylogenetic analyses of internal transcribed spacer (ITS) of nuclear ribosomal DNA (rDNA), translation elongation factor 1-alpha (TEF1) and β-tubulin (TUB2) genes, two species were identified: Neofusicoccum mediterraneum recovered from leaf spots on E. gillii in Tunisia and Neofusicoccum cryptoaustrale reported from leaf blight of E. torquata and E. odorata in Libya. Artificial inoculation trials on leaves confirmed the pathogenicity of the isolates to E. torquata, E. odorata and E. gillii. This report points out the threat posed by pathogens to non-native Eucalyptus in North Africa and suggests a likely movement of various pathogenic fungi from other hosts to Eucalyptus mainly E. ododrata trees that are totally infested by N. cryptoaustrale. Thus, it is recommended that E. odorata should not be planted in semi-arid areas. Further prospections of Eucalyptus arboretums are required to assess the incidence of foliar diseases on Eucalyptus plantations and to take appropriate and prompt measures against disease spread.