@article {EFP:EFP714, title = {Phytophthora root and collar rot of mature Fraxinus excelsior in forest stands in Poland and Denmark}, journal = {Forest Pathology}, volume = {41}, number = {6}, year = {2011}, pages = {510{\textendash}519}, publisher = {Blackwell Publishing Ltd}, abstract = {

In recent years, Common ash (Fraxinus excelsior) throughout Europe has been severely impacted by a leaf and twig dieback caused by the hyphomycete Chalara fraxinea. The reasons for its current devastating outbreak, however, still remain unclear. Here, we report the presence of four Phytophthora taxa in declining ash stands in Poland and Denmark. Phytophthora cactorum, Phytophthora plurivora, Phytophthora taxon salixsoil and Phytophthora gonapodyides were isolated from rhizosphere soil samples and necrotic bark lesions on stems and roots of mature declining ash trees in four stands. The first three species proved to be aggressive to abscised roots, twigs and leaves of F. excelsior in inoculation experiments. Soil infestation tests also confirmed their pathogenicity towards fine and feeder roots of ash seedlings. Our results provide first evidence for an involvement of Phytophthora species as a contributing factor in current decline phenomena of F. excelsior across Europe. Specifically, they may act as a predisposing factor for trees subsequently infected by C. fraxinea. Phytophthora species from ash stands also proved to be aggressive towards a wide range of tree and shrub species commonly associated with F. excelsior in mixed stands. Although damage varied considerably depending on the Phytophthora species/isolate-host plant combination, these results show that many woody species may be a potential source for survival and inoculum build-up of soilborne Phytophthora spp. in ash stands and forest ecosystems in general.

}, issn = {1439-0329}, doi = {10.1111/j.1439-0329.2011.00714.x}, url = {http://dx.doi.org/10.1111/j.1439-0329.2011.00714.x}, author = {Orlikowski, L.B. and Ptaszek, M. and Rodziewicz, A. and Nechwatal, J. and Thinggaard, K. and T. Jung} } @article {757, title = {First record on Phytophthora spp. associated with the decline of European beech stand in south-west Poland}, journal = {Phytopatologia Polonica}, volume = {42}, year = {2006}, pages = {37-46}, abstract = {

Phytophthora citricola was detected in Siewierz Forest District in soil samples and diseased bark taken from declined 88-111-year-old European beech trees growing in three compartments of Trzebyczka Forest. Phytophthora cambivora was isolated only from diseased fine roots, bleeding cankers near trunk base and aerial canker spots. Both species colonised leaves and young stem parts as well as five-year-old beech branches. Necrosis spread about 1 mm/24 h.

}, keywords = {Beech, bleeding canker, pathogenicity, root rot, soil}, author = {Orlikowski, L.B. and Oszako, T. and Szkuta, G} }