The interaction between Dicyma pulvinata and Fusicladium macrosporum was studied by scanning electron microscopy. Spores of D. pulvinata germinated on the surface of F. macrosporum lesions induced on artificially infected rubber plants were fixed 8 h after inoculation. D. pulvinata germ tubes seemed to elongate toward F. macrosporum. Close contact between the antagonistic fungus and F. macrosporum spores was verified 24 h after application of D. pulvinata. At the end of the process, spores of F. macrosporum seemed to have disintegrated and to be devoid of content. The hyperparasite grew completely over the pathogen. Six to seven days after application of the antagonistic fungus, D. pulvinata conidiophores were observed emerging from F. macrosporum structures with profuse sporulation. Studies have also shown the possibility of D. pulvinata producing hydrolytic enzymes, which could be associated with the control of plant pathogens. This information may help to elucidate some of the modes of action of D. pulvinata, a potential biological control agent for South American leaf blight of Hevea rubber plant.
pathogen and antagonistic interaction; South American Leaf Blight; Hevea brasiliensis; biocontrol
