04121nas a2200193   4500008004100000022001400041245012900055210006900184260001200253300001400265490000700279520349100286100001603777700001903793700001503812700001403827700001603841856007003857       2014                        eng d  a0191-291700aFoliar Blight and Shoot Dieback Caused by Phytophthora ramorum on Viburnum tinus in the Pistoia Area, Tuscany, Central Italy0 aFoliar Blight and Shoot Dieback Caused by Phytophthora ramorum o  c03/2014  a423 - 4230 v983 a<p class="first">In spring 2013, pot-grown <em>Viburnum tinus</em> plants shipped to an ornamental nursery in Pescia (Pistoia, central Italy, 287 m a.s.l., 43°54′0″ N, 10°41′0″ E) from another local nursery were found to bear disease symptoms. Symptoms included brown to black foliar lesions, later expanding into larger blotches; necrosis of the petioles; shoot wilting and folding; browning of the stems; and necrosis of the cambium. Infected leaves, shoots, and entire plants eventually died. Tissue samples (2 mm<sup>2</sup>) were cut at the edge of active lesions from tissue of the phloem, the xylem, and the leaves and plated on selective PARPNH V8 agar (V8A) (1). Rose-shaped and finely lobed cottony colonies arose in 2 to 3 days. Mono-hyphal colonies were isolated and transferred to V8A. Square colony pieces (1 cm<sup>2</sup>) from isolates SB05a and SB05b were placed in filtered pond water after 5 to 7 days. Semipapillate, caducous sporangia with a rounded or conical base were produced within 24 h, individually or in pairs, on each sporangiophore. Sporangia (<em>n</em> = 30 per isolate) were examined: they were 56.2 ± 9.5 × 29.3 ± 4.3 μm (l:b ratio 1.9 ± 0.3). Exit pores averaged 7.0 ± 1.0 μm. Sporangia were ellipsoid (30%), lemon-shaped (28.3%), ovoid (20%), obovoid (16.7%), ampulliform (3.3%), or “peanut-like” (1.7%). Globose chlamydospores, borne intercalarly or terminally, were abundant on both V8A and carrot agar (CA), and were on average 54.7 ± 8.5 μm. Mono-hyphal isolates incubated for 7 days at 23°C were also transferred to CA, corn meal agar (CMA), malt extract agar (MEA), potato dextrose agar (PDA), and V8A. Colonies on these media were identical in shape and appearance to those described in previous reports (2,4). Isolates were identified as <em>Phytophthora ramorum</em> Werres, De Cock &amp; Man in't Veld (4) on the basis of colony type; size, the average l:b ratio and shape of sporangia; and the type and size of the chlamydospores. Isolates were found to be the A1 mating type by pairing them with <em>P. cryptogea</em> BBA 63651 (mating type A2). PCR-amplification of the rDNA ITS region with specific primers Ph1/Ph4 (3) gave fragments of the expected size (GenBank Accession Nos. KF181162 and KF181163). A BLAST search of these ITS sequences in the database found that isolates of <em>P. ramorum</em> were the closest phylogenetically with 100% homology (YQ653034 and HM004221). Pathogenicity tests were conducted on 16 detached <em>V. tinus</em> leaves. A small cut was made aseptically on each of the leaf surfaces and a V8A disc (0.5 cm Ø) with mycelium was placed over the wounds. Control leaves received only sterile V8A discs. Inoculated and control leaves were incubated at 23°C in the dark. Necrotic areas (average 3.5 ± 1.3 cm<sup>2</sup>) arose on inoculated leaves after 6 days. Control leaves had no symptoms. Re-isolations on PARPNH V8A confirmed <em>P. ramorum</em> as the causal agent. <em>P. ramorum</em> was reported in Italy in 2003 on the exotic <em>Rhododendron yakushimanum</em> (2). This is the first report of the pathogen on a native species (<em>V. tinus</em>) in this country. The Pistoia area is important for nursery gardens and flowers. <em>P. ramorum</em>, which probably arrived on infected plant material, could compromise the export/import trade in stock plants. For this reason, the plant protection services were promptly alerted and the infected plants were destroyed.</p>1 aGinetti, B.1 aCarmignani, S.1 aRagazzi, A1 aWerres, S1 aMoricca, S.  uhttp://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-07-13-0767-PDN02603nas a2200277   4500008004100000022001400041245015200055210006900207260001200276300001400288490000700302520177700309653001602086653001202102653001302114653002002127653001402147653002702161100001602188700001602204700002002220700001702240700001502257700001302272856004002285       2013                        eng d  a1365-305900aPhytophthora acerina sp. nov., a new species causing bleeding cankers and dieback of Acer pseudoplatanus trees in planted forests in northern Italy0 aPhytophthora acerina sp nov a new species causing bleeding canke  c08/2014  a858–8760 v633 a<p>A severe dieback of <em>Acer pseudoplatanus</em> trees was noticed in planted forest stands in northern Italy in 2010. Affected trees showed collar rot and aerial bleeding cankers along the stems, leading to crown dieback and eventually death. An unknown <em>Phytophthora</em> species was consistently isolated from necrotic bark and xylem tissue and from rhizosphere soil. Based on its unique combination of morphological and physiological characters and phylogenetic analysis, this new taxon is here described as <em>Phytophthora acerina</em> sp. nov. Phylogenetic analysis of ITS,<em> cox1</em> and β-tubulin gene regions demonstrated that <em>P. acerina</em> is unique and forms a separate cluster within the ‘<em>P.&nbsp;citricola</em> complex’, closely related to <em>P.&nbsp;plurivora</em>. <em>Phytophthora acerina</em> is homothallic with smooth-walled oogonia, thick-walled, mostly aplerotic oospores with a high abortion rate, paragynous antheridia, and persistent, morphologically variable semipapillate sporangia. Four to 5-week-old cultures produced globose to subglobose, appressoria-like and coralloid hyphal swellings and characteristic stromata-like hyphal aggregations. Optimum and maximum temperatures for growth are 25°C and 32°C, respectively. Genetic uniformity of all 15 studied isolates and the apparent absence of this species in the extensive surveys of nurseries, forests and seminatural ecosystems conducted in the previous two decades across Europe indicate a recent clonal introduction to northern Italy. Under-bark inoculation tests demonstrated high aggressiveness of <em>P.&nbsp;acerina</em> to <em>A.&nbsp;pseudoplatanus</em> indicating that this pathogen might be a serious risk to maple plantations and forests in Europe.</p>10abiosecurity10aClade 210ainvasive10anursery pathway10aphylogeny10aPhytophthora citricola1 aGinetti, B.1 aMoricca, S.1 aSquires, J., N.1 aCooke, D E L1 aRagazzi, A1 aJung, T.  uhttp://dx.doi.org/10.1111/ppa.1215304151nas a2200181   4500008004100000022001400041245011100055210006900166260001600235300001600251490000700267520356300274100001603837700001903853700001503872700001603887856006603903       2014                        eng d  a0191-291700aPhytophthoraTaxon Pgchlamydo is a Cause of Shoot Blight and Root and Collar Rot of Viburnum tinus in Italy0 aPhytophthoraTaxon Pgchlamydo is a Cause of Shoot Blight and Root  cJan-10-2014  a1432 - 14320 v983 a<p>The quarantine pathogen <em>Phytophthora ramorum</em> has recently been found on dying <em>Viburnum tinus</em> in the nursery area of Pistoia, central Italy (43°56′0″ N, 11°1′0″ E) (3). As part of a surveillance program aimed at detecting <em>P. ramorum</em> in this area, the <em>Phytophthora</em> taxon Pgchlamydo was consistently found associated with symptomatic <em>V. tinus</em>. The crowns of these plants were wilted, and some plants also showed root and collar rot and underbark necrosis. Water courses adjacent to the nursery with the infected <em>V. tinus</em> were tested for the pathogen. Samples from seven symptomatic plants were placed on a selective V8A-PARPNH medium within 24 h from sampling. Tissue pieces (2 mm<sup>2</sup>) of 12 baits (apple fruits) exposed for a week in water bodies were plated on the same medium. Cottony colonies arose after 2 to 3 days of incubation at 23°C in the dark and were transferred to potato dextrose agar (PDA) in purity. Mycelial DNA was extracted with a commercial kit (Sigma-Aldrich). The rDNA ITS region and a portion of the mtDNA <em>cox</em>1 gene were PCR-amplified and the amplicons digested with the restriction enzymes <em>Msp</em>I and <em>Alu</em>I (for the ITS region) and <em>Rsa</em>I (for the <em>cox</em>1 gene region). Isolates R7 from <em>V. tinus</em>, and ES2M5, ES2M11, and ES1M12 from the water bodies belonged to the same taxon based on restriction analysis of both DNA regions coupled with ITS-rDNA sequence homology (GenBank Accession Nos. KJ396773 to 76). A BLAST search in GenBank found that all isolates had a 99% identity in the ITS-rDNA with the <em>Phytophthora</em> ITS Clade 6 member <em>P.</em> taxon Pgchlamydo. Sporangia produced after incubation in filtered pond water for 24 h were mostly ovoid (sometimes obpyriform), non-papillate, non-caducous. Some sporangia were emptied with external proliferation and had hyphal swellings. Thirty sporangia were measured and averaged 42.4 ± 6.2 × 29.9 ± 3.5 μm (range 30.0 to 56.1 × 22.5 to 38.0), with a length/width ratio of 1.4 ± 0.2 (1.2 to 2.0), and exit pores of 11.7 ± 1.5 μm (9.0 to 14.6). Optimum colony growth on V8A at 30°C was 4.4 ± 0.4 mm day<sup>–1</sup>, and the maximum temperature for growth was 32°C. Inoculation on twigs of <em>Fagus sylvatica</em> and <em>V. tinus</em> produced necrotic lesions of 2.6 ± 0.5 cm (2.1 to 3.5) and 4.7± 0.5 cm (3.8 to 5.6) respectively after 3 weeks of incubation at 23°C in the dark. Inoculation on <em>V. tinus</em> leaves resulted in lesions averaging 3.3 ± 1.1 × 2.1 ± 0.6 cm (range 2 to 5 × 1.5 to 3) after 2 weeks of incubation at 23°C in the dark. Control plant material showed no symptoms.The <em>Phytophthora</em> taxon Pgchlamydo has been reported on several ornamental and woody species, including <em>Arctostaphylos</em> sp., <em>Camellia</em> spp., <em>Laurus nobilis, Buxus sempervirens, Rhododendron</em> sp., <em>Arbutus unedo, Prunus</em> sp., <em>Pseudotsuga</em> sp., and <em>Sequoia sempervirens</em>, in North America and Europe (1,2). This is the first report, to our knowledge, of this taxon on <em>V. tinus</em> in Italy. <em>V. tinus</em> is widely sold in European nurseries, and it is also one of the most common hosts of <em>P. ramorum</em> (4). The fact that <em>V. tinus</em> is a host for both oomycetes, and the two microorganisms induce a similar symptomology (wilt), might complicate the control efforts of the phytosanitary inspection services aimed at restricting <em>P. ramorum</em> foci in Europe.</p>1 aGinetti, B.1 aCarmignani, S.1 aRagazzi, A1 aMoricca, S.  uhttp://apsjournals.apsnet.org/doi/10.1094/PDIS-03-14-0282-PDN