@article {3966, title = {First report of Phytophthora cactorum associated with beech decline in Italy}, journal = {Plant Disease}, volume = {92}, year = {2008}, month = {12/2008}, pages = {1708 - 1708}, abstract = {

During 2006 and 2007, declining mature beech trees (Fagus sylvatica) were recorded in two stands in the Natural Park of Monti Cimini in central Italy. Symptoms included crown thinning and the presence of bleeding lesions on the main roots and lower stem. Incidence of decline was approximately 5\%. Samples of necrotic bark tissue were collected, cut into 5 mm long segments, plated on PARPNH, and incubated at 20{\textdegree}C (1). Phytophthora isolates were obtained from necrotic tissues of 25\% of the sampled declining trees. Colonies were rosaceous on potato dextrose agar (PDA) and homothallic. Papillate, ovoid-to-obpyriform, caducous sporangia (mean 38 {\texttimes} 26.2 μm) were produced in soil extract. Oospores were plerotic (mean diameter of 22 to 32 μm) and antheridia paragynous. Optimum growth temperature was 23 to 25{\textdegree}C, minimum 6 to 8{\textdegree}C and maximum 30 to 33{\textdegree}C. A portion of the internal transcribed spacer sequence has been deposited in the NCBI database (GenBank Accession No. FJ183724). A BLAST search of the NCBI database revealed Phytophthora cactorum, Accession No. EU194384, as the closest match with 100\% sequence similarity. Pathogenicity of two isolates, PFE3 and IFB-CAC 38, collected from distressed beech trees was tested using a soil infestation test (10 beech seedlings per isolate and control) and an under the bark inoculation method (10 twigs per isolate and controls, wounded and noninoculated taken from a declining beech tree) (2). After 2 weeks at 20{\textdegree}C, twigs and seedlings inoculated with each isolate developed extensive necrotic lesions around the inoculation sites and the collar, respectively, and P. cactorum could be reisolated from all lesions. Controls showed no symptoms. P. cactorum is widespread in declining beech forests in central Europe (1). In Italy, P. cactorum occurs in soils of chestnut and oak forests and was isolated from collar and root lesions of declining walnut trees (3). To our knowledge, this is the first report of P. cactorum being associated with declining beech trees in Italy.

}, issn = {0191-2917}, doi = {10.1094/PDIS-92-12-1708A}, author = {A.M. Vettraino and T. Jung and A. Vannini} } @article {1324, title = {Phytophthora ramorum infection of coast live oak leaves in Californian forests and its capacity to sporulate in vitro}, journal = {Australasian Plant Pathology}, volume = {37}, year = {2008}, pages = {72-73}, publisher = {Springer Netherlands}, abstract = {

Coast live oak (Quercus agrifolia) is a known host for Phytophthora ramorum, the casual agent of sudden oak death in California, with symptoms expressed as necrotic stem cankers. In the forest, leaves on two saplings in California were found to be infected with P. ramorum and these were associated with infected bay laurel (Umbellularia californica) trees. Coast live oak leaves supported sporulation and produced chlamydospores in vitro. This is the first report to identify foliage of coast live oak as a source of infection of P. ramorum in the forest and its confirmation in in vitro inoculations.

}, issn = {0815-3191}, doi = {10.1071/AP07085}, url = {http://dx.doi.org/10.1071/AP07085}, author = {A.M. Vettraino and H{\"u}berli, D. and Garbelotto, M.} } @article {PPA:PPA839, title = {Scotch broom: a new host of Phytophthora megasperma in Italy}, journal = {Plant Pathology}, volume = {52}, number = {3}, year = {2003}, pages = {417{\textendash}417}, publisher = {Blackwell Science Ltd}, issn = {1365-3059}, doi = {10.1046/j.1365-3059.2003.00839.x}, url = {http://dx.doi.org/10.1046/j.1365-3059.2003.00839.x}, author = {A.M. Vettraino and A. Vannini} } @article {EFP:EFP264, title = {Occurrence of Phytophthora species in oak stands in Italy and their association with declining oak trees}, journal = {Forest Pathology}, volume = {32}, number = {1}, year = {2002}, pages = {19{\textendash}28}, publisher = {Blackwell Science Ltd.}, abstract = {

Soil-borne species of Phytophthora were isolated from 19 of 30 examined oak forest areas in Italy. The frequency of isolated Phytophthora spp. (35.2\%) was significantly correlated with soil pH and longitude of the sites. Eleven Phytophthora species were detected. Phytophthora cambivora, P. cinnamomi and P. cactorum were recovered from sites in central and southern Italy whereas P. quercina was isolated in the northern and central part of the country. Phytophthora citricola occurred all over Italy. Phytophthora quercina was the only species significantly associated with declining oak trees.

}, issn = {1439-0329}, doi = {10.1046/j.1439-0329.2002.00264.x}, url = {http://dx.doi.org/10.1046/j.1439-0329.2002.00264.x}, author = {A.M. Vettraino and Barzanti, G. P. and Bianco, M. C. and Ragazzi, A. and Capretti, P. and Paoletti, E. and Luisi, N. and Anselmi, N. and A. Vannini} } @article {PPA:PPA864, title = {Evaluation of root damage to English walnut caused by five Phytophthora species}, journal = {Plant Pathology}, volume = {52}, number = {4}, year = {2003}, pages = {491{\textendash}495}, publisher = {Blackwell Science Ltd}, abstract = {

The pathogenicity of five species of Phytophthora to English walnut was studied in a greenhouse experiment. Phytophthora cinnamomi was the most aggressive species, causing severe root rot and seedling mortality. The other species tested, P. cambivora, P. citricola, P. cactorum and P. cryptogea, did not induce visible crown symptoms on seedlings 2 months after inoculation. Some strains of P. cambivora and P. cactorum also caused taproot damage to seedlings. All except one of the tested isolates caused significant necrosis of fine roots and a significant reduction of root weight compared with noninoculated seedlings. Reduction of above-ground plant development was not statistically significant. While P. cinnamomi is well known as an aggressive primary pathogen of English walnut, the other species of Phytophthora may act as predisposing factors to walnut decline, affecting root system development and increasing host vulnerability to environmental stress.

}, keywords = {English walnut, Juglans regia, pathogenicity, soilborne pathogens, walnut decline}, issn = {1365-3059}, doi = {10.1046/j.1365-3059.2003.00864.x}, url = {http://dx.doi.org/10.1046/j.1365-3059.2003.00864.x}, author = {A.M. Vettraino and Belisario, A. and Maccaroni, M. and A. Vannini} }