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The most economically damaging ilarvirus affecting hazelnut on a worldwide scale is the related apple mosaic virus (ApMV). Attempts were made to isolate the virus RNA from hazelnut tissues using different extraction methods. The most suitable extraction method that could detect the virus occurring naturally in hazelnut by reverse-transcription polymerase chain reaction (RT-PCR) methodology was selected. RT-PCR was applied successfully using flower, husk and leaf tissues. The most suitable extraction method and hazelnut tissues determined were sensitive, simple, rapid and reliable for simultaneous detection of ApMV in hazelnut tissues. To our knowledge, this is the first report of the simultaneous detection of the virus by RT-PCR, an alternative detection of ApMV in hazelnut hosts.

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Almond (Prunus dulcis) production is currently increasing in Turkey. Losses of approximately 1% associated with root and crown rot of almond seedlings were observed in two commercial nurseries in Ankara and Düzce provinces in 2009. Aboveground symptoms were leaf chlorosis and wilt. Feeder roots were decayed, necrosis occurred on taproots and basal stems, and plants collapsed within several weeks. Roots were washed in tap water and 9 to 10 pieces (3 to 5 mm long) of root tissue taken from the margins of canker lesions, without surface disinfection, were placed on selective medium P5ARPH-CMA (2). Plates were incubated for 3 to 5 days at 20°C in darkness and a number of Phytophthora spp. were recovered. Actively growing mycelium was transferred to carrot piece agar containing β-sitosterol (per liter: carrot piece, 40 g; agar, 20 g; β-sitosterol, 20 mg). Isolates were identified as Phytophthora cactorum and P. citrophthora on the basis of morphological characteristics (1). P. cactorum produced abundant sporangia, oogonia, and paragynous antheridia on carrot piece agar plus β-sitosterol. It had conspicuously papillate and caducous sporangia with short pedicel. Sporangia were usually ovoid but sometimes nearly spherical. P. citrophthora did not produce sexual structures in single culture. It produced papillate, noncaducous sporangia, which were usually ovoid and obpyriform, often asymmetrically shaped and rarely possessed more than one apex. P. citrophthora did not grow at 35°C but it grew well at 30°C. Isolate identities were confirmed by sequence analysis of the ribosomal DNA internal transcribed spacers 1 and 2 (GenBank Accession Nos. HM357622, HM357623, HM357624, HM357625) using primers ITS1 and ITS2 (3). One representative isolate of each species was used to inoculate eight 2-year-old almond plants with an agar plug with actively growing mycelium that was attached to exposed cambium of basal stems. Agar plugs without mycelium were used for eight control plants. All plants inoculated with Phytophthora spp. collapsed within 3 to 4 weeks. Control plants remained healthy. Phytophthora spp. were reisolated from necrotic basal stems. To our knowledge, this is the first report of P. cactorum and P. citrophthora of almond in Turkey. References: (1) M. E. Gallegly and C. Hong. Phytophthora, Identifying Species by Morphology and DNA Fingerprints. The American Phytopathological Society, St. Paul, MN, 2008. (2) S. N. Jeffers and S. B. Martin. Plant Dis. 70:1038, 1986. (3) S. G. Roy et al. J. Phytopathol. 157:666, 2009.

Grape (Vitis vinifera) is widely planted and is an economically important crop in Turkey for domestic consumption and export. Black foot disease, caused by Cylindrocarpon macrodidymum Halleen, Schroers & Crous, is a recently identified but worsening problem in vineyards worldwide (3,4). Symptomatic grapevines show reduced vigor, shortened internodes, small leaves with interveinal chlorosis, and necrosis frequently leading to the death of the plants (1). Roots of symptomatic grapevines exhibit black, sunken, necrotic lesions with a reduction in root biomass. Pith of affected vines is discolored (4). During the summers of 2009 and 2010, a survey was carried out in 63 vineyards (4 to 15 years old) in six locations of Ankara Province. We collected 44 samples from roots and crowns of grapevines exhibiting black foot symptoms. In cross section, extensive necrosis at the base of the trunk and brown-black spots in xylem vessels were observed, resembling those previously reported for black foot disease (2,4). Isolations were made from roots, vascular elements, and pith tissue. In this study, 26 isolates were identified as C. macrodidymum on the basis of morphological characteristics. Isolates identified as C. macrodidymum had a dark orange-brown colony color and abundant aerial mycelia when grown on potato dextrose agar. Isolates produced ellipsoid or ovoid microconidia. The macroconidia were one to three septate, straight, and cylindrical. One-septate macroconidia were 24 to 32 × 5 to 7 μm; three-septate macroconidia were 26 to 40 × 5 to 6 μm. Chlamydospores developed in short, intercalary chains. Conidiophores were simple or complex and sporodochial. Isolate identities were confirmed by sequence analysis of the ribosomal DNA internal transcribed spacer (GenBank Accession No. HM245331) with primers ITS1 and ITS4 (4). Isolates had 99% genetic identity with other isolates of C. macrodidymum present in GenBank. In pathogenicity tests, one representative isolate was used to inoculate five grapevine plants. Tests were completed by drench inoculation onto 3-month-old rooted cuttings of cv. Sultana with 25 ml of a conidia suspension (106 conidia ml–1). Controls were inoculated with an equal volume of sterile distilled water. Plants were incubated for 4 months in a controlled environment facility at 25°C. After 3 to 4 months, inoculations resulted in reduction of root mass, and C. macrodidymum was reisolated from regions of brown streaking in wood and discolored vascular tissue in all inoculated plants, fulfilling Koch's postulates. Control plants were asymptomatic and C. macrodidymum was not recovered from control plants. To our knowledge, this is the first report of the presence of C. macrodidymum causing black foot disease on grapevine in Turkey. References: (1) S. Alaniz et al. Plant Dis. 93:821, 2009. (2) F. Hallen et al. Stud. Mycol. 50:431, 2004. (3) F. Halleen et al. Phytopathol. Mediterr. 45:S55, 2006. (4) E. Petit and W. D. Gubler. Plant Dis. 89:1051, 2005.