Zagrożenie sosny zwyczajnej (Pinus sylvestris L.) w Polsce ze strony Gibberella circinata

Since its initial discovery in 1945, pitch canker caused by Gibberella circinata (anamorph Fusarium circinatum) has become one of the most important pine diseases in the world. It infests 57 pine species (including Pinus sylvestris) and Douglas−fir. F. circinatum has been reported in both nurseries and forests on all continents except Australia and Oceania. Both vegetative and reproductive parts of the host plant (i.e. stem, branches, roots, flowers, cones and seeds) can be infected by F. circinatum. For mature trees, the main symptoms include bleeding resinous cankers on the stem and branches as well as tree death. In nurseries, F. circinatum causes pre− and post−emergence damping off as well as mortality of older seedlings. Dispersal of fungal spores occurs through air, water splash, soil, insect vectors and translocation of the infected plant material. Currently there are no effective means of controlling pitch canker, although there is ongoing research into using chemical, physical and biological methods, quarantine and breeding for resistance to control this disease. The occurrence of the disease depends mainly on the presence and density of the host species, favorable climatic conditions (especially high humidity), presence of suitable vectoring and wounding agents and various stress factors. Taking into account the above−mentioned factors, threat to Scots pine in Poland should be considered marginal, but it cannot be ruled out completely. KEY WORDS