Dothistroma needle blight Mycosphaerella pini E. Rostrup and its anamorphic stage Dothistroma septospora (Dorog.) Morelet was detected for the first time in the territory of the Czech Republic in a consignment of imported plants of Austrian pine Pinus nigra Arnold in 1999. In 2000, it was also found on Pinus nigra in an open planting in a plantation of Christmas trees by the village of Jedovnice near Brno in South Moravia. In the Czech Republic, Dothistroma needle blight was identified on 13 species of pine. Pinus nigra Arnold and Pinus mugo Turra are the most frequent hosts. In addition to these species, Dothistroma needle blight was observed on Pinus ponderosa Douglas ex Lawson, Pinus jeffreyi Grev. et Balf, Pinus banksiana Lamb., Pinus contorta Douglas, Pinus rotundata Link, Pinus leucodermis Ant. and Pinus sylvestris L. Finds on Pinus aristata Engelm., Pinus rigida Mill., Pinus heldreichii H. Christ. and Pinus cembra L. var. sibirica (Du Tour) G. Don. are a certain rarity. These species are not mentioned anywhere as potential hosts of Dothistroma needle blight. As for the species of other genera Picea pungens Engelm., Picea abies L. Karst. and last but not least Picea schrenkiana Fisch. & C. A. Mey were also observed as hosts. The host range of Dothistroma needle blight recorded in papers is noted as well.

, and their potential application for laccase and peroxidases induction have been tested. The enzyme-inducing activities of the complexes were compared with that of copper sulfate, and it has been found that all of the complexes are suitable for the induction of laccase and peroxidase activities in white-rot fungi; however, the newly-synthesized complex M1 showed the greatest potential for the induction. With respect to the different copper inducers, this parameter seems to be important for enzyme activity, which depends also on the fungal strains.

Dothistroma needle blight caused by Mycosphaerella pini E. Rostrup was observed for the first time in the Czech Republic on an imported Pinus nigra Arnold in 1999. In 2000, it was also found in the open planting. During three years, it became an important pathogen of pines in the Czech Republic. Its occurrence was noticed in more than 50 localities, above all in the region of Moravia and Silesia and eastern Bohemia. In total, it was found on 10 species of pine (P. nigra Arnold, P. banksiana Lamb., P. contorta Loudon, P. mugo Turra, P. leucodermis Ant., P. sylvestris L., P. cembra L., P. aristata Engelm., P. ponderosa P. et C. Lawson and P. jeffreyi Grev. et Balf.). Also Picea pungens Engelm. was noticed as a host species. In the Czech Republic, Pinus nigra is the most frequent host species of M. pini (80% localities) followed by Pinus mugo (27% localities). On Scots pine P. sylvestris, M. pini was noticed at two localities. The critical period for infection is in the Czech Republic from the second half of May until the end of June. The incubation period lasts about 2-4 months depending on climatic conditions. The first symptoms on the needles infected in the current year appear in August being clearly expressed from September to November. In the CR, Dothistroma needle blight spread probably with infected planting stock obtained from import at the end of the 80s and at the beginning of the 90s.

There are two records of brown spot needle blight caused by <I>L. acicola</I> in the Czech Republic up to date. Disease was first reported on June 2007 in National Nature Reserve (NNR) Červená Blata, South Bohemia. A more recent discovery of <I>L. acicola</I> took place on August 2008 in the NNR Borkovická Blata. The disease was observed on 10-60 year old <I>Pinus rotundata</I>. Both locations with infected trees are situated inside nature conservation sites under strict protection regimes that are located approximately 50 km apart. In both sites, <I>L. acicola</I> occurred simultaneously with <I>Dothistroma septospora</I>, the red band needle blight causal agent on Scots pine (<I>Pinus sylvestris</I>), bog pine (<I>P. rotundata</I>) and their hybrid (<I>P. × digenea</I>). However, infections of both diseases on the same tree have not yet been observed.

Since 1911, dothistroma needle blight, caused by Dothistroma septosporum, has been recorded in most European countries. In the Czech Republic, the fungus has become an important disease of pines since 2000, especially Austrian pines in plantations of Christmas and ornamental trees. The aim of this study was to analyse the population structure, gene flow and mode of reproduction of this pathogen. Microsatellite and mating-type markers were analysed in a Dothistroma population in the southeastern part of the country using reference isolates from other European countries. The haplotypic diversity was high, with 87 unique and 13 shared haplotypes (probable clones) identified in 121 samples. Based on STRUCTURE analysis, the isolates were divided into two populations, with an uneven distribution over the sampling sites. The grouping of the sites to the populations did not follow a geographical pattern because certain isolates that were sympatrically co-occurring at the same site were placed in different populations. Tests for random mating (the index of association and a parsimony tree-length permutation test) showed a significant clonal mode of reproduction in most cases, but the intrapopulation haplotypic diversity is unexpectedly high. Although a teleomorphic stage of D. septosporum has not been previously observed in the Czech Republic, the high intrapopulation haplotypic diversity can be explained by infrequent sexual reproduction consistent with the occurrence of both mating types.