OPHIOSTOMA-POLONICUM IS A SPECIES OF CERATOCYSTIS-SENSU-STRICTO

Ophiostoma polonicum was first isolated in Poland and described in 193 9 by Siemaszko. The fungus is a serious pathogen of spruce and is vect ored by the bark beetle Ips typographus. Ophiostoma polonicum was desc ribed as producing a Leptographium anamorph similar to that of Ophiost oma penicillatum. The fungus was later transferred to Ceratocystis pen icillata but is currently treated as a species of Ophiostoma. Examinat ion of the culture collected by Siemaszko and also from recent collect ions from spruce in Europe and Japan have shown the presence of a Chal ara state. Cell polysaccharide analysis revealed the absence of rhamno se in the cells of O. polonicum which is more typical of Ceratocystis species. The fungus was also found to be sensitive to cycloheximide, w hich is characteristic of species of Ceratocystis sensu stricto. Compa risons of partial sequence data of the ribosomal DNA operon have also revealed that isolates of O. polonicum group together with Ceratocysti s laricicola, which is a well defined species of Ceratocystis sensu st ricto. We, therefore, conclude from this study that O. polonicum is a typical species of Ceratocystis s.str. and also that the species is ve ry likely conspecific with C. laricicola.