Pathogenicity of some Ips typographus-associated blue-stain fungi to Norway spruce

Abstract

To test the pathogenicity of Ips typographus-associated fungi to Norway spruce, trees were inoculated with four species, Ophiostoma polonicum, O. bicolor, O. penicillltum and Graphium sp. Trees inoculated with the three Ophiostoma species produced strong hypersensitive responses in the phloem and exuded more resin than did the control trees. Only O. polonicum was able to invade the sapwood and consequently able to kill trees. Inoculation with Graphium sp. gave the same response as inoculation with the control.