Invasive Species Compendium

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Abstract Full Text

Pine needle diseases in Slovenia, caused by fungi from the Mycosphaerella genus.

Abstract

In Slovenia, pines (Pinus spp.) are frequently damaged by numerous autochthonous diseases and pests, but introductions of alien harmful organisms represent even higher dangers for pine trees. Estimated loss as a consequence of these introductions will be a sum of direct losses connected to the disease or damages and losses connected to rigorous measures taken to eradicate or to prevent the disease expansion, which could additionally negatively affect our forests. Some of these harmful organisms are already recognized and listed on the lists of the Council Directive 2000/29/EC and of the European and Mediterranean Plant Protection Organization (EPPO). Among them the following two diseases are found: brown spot needle blight caused by Mycosphaerella dearnessii (anamorph Lecanosticta acicola) and red band needle blight caused by two morphologicaly similar species Dothistroma septosporum (teleomorph M. pini) and D. pini (teleomorph unknown). The latter two species were identified in 2004 and can only be identified based on molecular data. All three mentioned species are not widely spread in Europe. But in the recent years the extent and the intensity of the disease, caused by Dothistroma species have increased, especially in England and Nordic countries. Latest genetic analyses have shown that for further disease development in Europe import of a not yet present mating type would be critical. This would trigger a higher genetic variability and the possibility of new pathogenic strains would be enhanced. Subsequently, a monitoring of the presence and diversity of Dothistroma fungi and M. dearnessii has been performed in 2012 in Slovenia in the context of the National survey program. The results of this survey are in accordance of the similar surveys performed in Europe and supplement the existing knowledge about the D. pini distribution. Also, the results indicate the value of regular monitoring, which could serve as an important basis for possible actions at disease outbreaks or to limit the disease spread.