Aziz Karakaya

First Report of Bacterial Canker of Kiwifruit Caused by Pseudomonas syringae pv. actinidiae in Turkey

A new disease was observed during the spring and autumn of 2009 and 2010 on kiwifruit plants (Actinidia deliciosa cv. Hayward) in Rize Province of Turkey. Disease incidence was estimated as 3% in approximately 10 ha. Symptoms were characterized by dark brown spots surrounded by yellow halos on leaves and cankers with reddish exudate production on twigs and stems. Eight representative bacterial strains were isolated from leaf spots and tissues under the bark on Kings B medium (KB) and identified as Pseudomonas syringae pv. actinidiae on the basis of biochemical, physiological (1,2), and PCR tests (3). Bacteria were gram negative, rod shaped, and nonfluorescent on KB; positive for levan production, sucrose and inositol utilization, and tobacco (Nicotiana tabacum cv. White Burley) hypersensitivity; and negative for growth at 37°C, oxidase, potato soft rot, arginine dihydrolase, urease, arbutin, erythritol, lactic acid, aesculin hydrolysis, gelatin liquefaction, and syringomycin production. Identity of the eight isolates was confirmed by PCR using P. syringae pv. actinidiae-specific primers PsaF1/R3 to generate a 280-bp DNA fragment (3). P. syringae pv. actinidiae reference strain NCPPB 3739, and CJW7 from Jae Sung Jung, Department of Biology, Sunchon National University, Korea, were employed in all biochemical, physiological, and molecular tests as positive controls. Pathogenicity was confirmed by artificial inoculation of 2-year-old A. deliciosa cv. Hayward. A bacterial suspension (108 CFU ml-1) was injected into kiwifruit twig tips, stems, and leaves with a hypodermic syringe, and the inoculated plants were placed at 25 to 28°C and 80% relative humidity growth chamber for 3 weeks. First symptoms were observed on leaves within 5 days after inoculation and on twigs after 20 days. No symptoms were observed on control plants that were inoculated with sterile water. Reisolation was made from dark brown lesions surrounded by yellow halos on leaves and cankers on twigs and stem and their identities were confirmed using the techniques previously described. All tests were performed three times and pathogenicity tests employed three plants for each strain. To our knowledge, this is the first report of P. syringae pv. actinidiae causing disease on kiwifruit in Turkey. Kiwifruit production in Turkey has expanded rapidly during the last 10 years ( http://www.tuik.gov.tr ) and phytosanitary measures are needed to prevent further spread of the bacterium to other kiwifruit orchards. References: (1) Y. J. Koh et al. N. Z. J. Crop Hortic. Sci. 38:4, 275, 2010. (2) R. A. Lelliott and D. E. Stead. Methods for the Diagnosis of Bacterial Diseases of Plants. Blackwell Scientific, Sussex, UK, 1988. (3) J. Rees-George et al. Plant Pathol. 59:453, 2010.

Diversity of sooty blotch and flyspeck fungi from apples in northeastern Turkey

Sooty blotch and flyspeck (SBFS) is a mid- to late-season fungal disease complex that blemishes apples and other tree fruit crops in humid regions worldwide. SBFS is a concern for apple growers in northeastern Turkey, but the composition of the SBFS species assemblage in Turkey is unknown. In this study, SBFS fungi were isolated from apples collected in 2008 in the Rize Province of northeastern Turkey. Pressed SBFS colonies with subtending apple cuticle were shipped to Iowa State University for isolation. Of 633 primary isolates from 148 apple peels, 87 cultures were purified, 67 isolates were genetically characterized and 33 isolates examined for morphology. The internal transcriber spacer (ITS) ribosomal DNA and a portion of the 28S large subunit region (LSU) were compared to previously identified fungi using parsimony analysis. Putative species were delineated from ITS sequences as well as morphology on apple and in culture. Twelve species were delineated based on parsimony analysis of ITS sequences and morphology. A newly discovered and described species from the survey was Scleroramularia abundans; newly discovered putative species included Zygophiala sp. FS3.3, Stomiopeltis spp. RS7.1 and RS7.2, and Chaetothyriales sp. F1; previously recovered putative species included Zygophiala sp. FS6 and Stomiopeltis sp. RS4.1; and previously discovered and named SBFS species included Schizothyrium pomi, Zygophiala wisconsinensis, Microcyclosporella mali, Microcyclospora tardicrescens, and Peltaster fructicola. Based on parsimony analysis of the LSU, one species was placed in the subclass Chaetothyriomycetidae and 11 species were placed in subclass Dothideomycetidae. Ten species were placed in the order Capnodiales. These findings expand the documented extent of genetic diversity within the worldwide SBFS complex and are the first published description of the composition of the SBFS complex from Turkey.

Scleroramularia gen. nov. associated with sooty blotch and flyspeck of apple and pawpaw from the Northern Hemisphere

Scleroramularia is proposed as a new hyphomycetous fungal genus associated with sooty blotch and flyspeck (SBFS) blemishes of apple and pawpaw fruit in the Northern Hemisphere. Morphologically the genus closely resembles Ramularia (Mycosphaerellaceae), based on its chains of hyaline conidia, with thickened, darkened, somewhat refractive conidiogenous loci. Scleroramularia is distinguished by forming black sclerotial bodies in culture, and having conidial chains that do not quickly disarticulate as observed in Ramularia. Based on the nuclear ribosomal DNA phylogeny (LSU), Scleroramularia represents an undescribed order in the Dothideomycetes, clustering between the Pleosporales and the Botryosphaeriales. Further analysis of morphology in combination with DNA phylogeny of the nuclear ribosomal ITS region and partial translation elongation factor 1-alpha (TEF) gene sequences delimited five species. These include S. asiminae on Asimina triloba (pawpaw fruit) in the U.S.A., and four other species occurring on apple fruit, namely S. abundans (on a local cultivar in Ardeşen, Rize, Turkey), S. shaanxiensis (on ‘Fuji’ in China), S. pomigena (on ‘Golden Delicious’ in the U.S.A.), and S. henaniensis (on ‘Fuji’ in China, and ‘Golden Delicious’ and ‘Gold Rush’ in the U.S.A.). Morphologically these taxa can be distinguished based on a combination of culture characteristics and conidial morphology in vitro, which is reflected in a key to the species treated.

First Report of Infection of Kiwifruit by Pestalotiopsis sp. in Turkey

Circular to irregular brown leaf spots, 0.2 to 1.5 cm in diameter, were commonly observed on kiwifruit (Actinidia deliciosa) cv. Hayward plants in the Artvin-Arhavi region of northeastern Turkey. Leaf spots sometimes covered large portions of infected leaves, giving them a blighted appearance. Fruit symptoms consisted of brown, sunken, shriveled areas that were 0.5 to 3 cm in diameter. A fungus, later identified as a Pestalotiopsis sp. (1), was consistently isolated from diseased tissues. Pathogenicity tests were performed on 2-year-old kiwifruit plants and mature fruits at 18/22°C (day/night). A spore suspension (1 × 106 conidia per ml) was sprayed on leaves of 2-year-old kiwifruit plants. Agar pieces, 3 mm in diameter, from 10-day-old cultures also were applied to the leaves. Controls were treated with water and agar alone. Plants were covered with plastic bags for 3 days to ensure high humidity. After 2 weeks, disease symptoms were observed on inoculated leaves. Pestalotiopsis sp. was consistently isolated from these regions. Agar pieces from 10-day-old cultures were placed in small wounds made on the surfaces of mature, surface-disinfested fruits. Controls were treated with agar pieces alone. Softening of tissues next to the wound was observed 1 week after inoculation. Pestalotiopsis sp. was isolated from these areas. No symptoms were observed on noninoculated leaves or fruits. It was concluded that this disease is caused by Pestalotiopsis sp. This is the first report of its occurrence in Turkey. Reference: (1) T. R. Nag Raj. Coelomycetous anamorphs with appendage bearing conidia. Mycologue Publications, Ontario, Canada, 1993.

Botrytis disease of kiwifruit in Turkey

Botrytis cinerea infection of kiwifruit was reported for the first time from Rize, Turkey. The pathogen caused leaf blights. It is found in Rize central district, Ardesen, Pazar, Çayeli, Fındıklı and Güneysu districts. Isolates were confirmed to be B. cinerea using polymerase chain reaction with specific primers C729± that amplified a 700 bp fragment.

Identity and pathogenicity of Fusarium species associated with crown rot on wheat (Triticum spp.) in Turkey

An extensive survey was carried out to collect Fusarium species colonizing the lower stems (crowns) of bread wheat (Triticum aestivum L.) and durum wheat (T. durum Desf.) from different wheat growing regions of Turkey in summer 2013. Samples were collected from 200 fields representing the major wheat cultivation areas in Turkey, and fungi were isolated from symptomatic crowns. The isolates were identified to species level by sequencing the translation elongation factor 1-alpha (TEF1-α) gene region using primers ef1 and ef2. A total of 339 isolates representing 17 Fusarium species were isolated. The isolates were identified as F. culmorum, F. pseudograminearum, F. graminearum, F. equiseti, F. acuminatum, F. brachygibbosum, F. hostae, F. redolens, F. avenaceum, F. oxysporum, F. torulosum, F. proliferatum, F. flocciferum, F. solani, F. incarnatum, F. tricinctum and F. reticulatum. Fusarium equiseti was the most commonly isolated species, accounting for 36% of the total Fusarium species isolated. Among the damaging species, F. culmorum was the predominant species being isolated from 13.6% of sites surveyed while F. pseudograminearum and F. graminearum were isolated only from 1% and 0.5% of surveyed sites, respectively. Six out of the 17 Fusarium species tested for pathogenicity caused crown rot with different levels of severity. Fusarium culmorum, F. pseudograminearum and F. graminearum caused severe crown rot disease on durum wheat. Fusarium avenaceum and F. hostae were weakly to moderately virulent. Fusarium redolens was weakly virulent. However, F. oxysporum, F. equiseti, F. solani, F. incarnatum, F. reticulatum, F. flocciferum, F. tricinctum, F. brachygibbosum, F. torulosum, F. acuminatum and F. proliferatum were non-pathogenic. The result of this study reveal the existence of a wide range of Fusarium species associated with crown rot of wheat in Turkey.

First report of Alternaria alternata infection of kiwifruit in Turkey

A leaf spot disease of kiwifruit caused by Alternaria alternata is reported for the first time from Turkey.

Powdery mildews observed on Onobrychis spp. in Turkey

Erysiphe trifolii and Leveillula taurica on Onobrychis spp. in Turkey, are described and illustrated.

ANKARA ÜNİVERSİTESİ ZİRAAT FAKÜLTESİ YONCA EKİM ALANLARINDA GÖRÜLEN ÖNEMLİ HASTALIKLARIN BELİRLENMESİ

Bu calisma ile Ankara Universitesi Ziraat Fakultesi Ayas ve Haymana ciftlikleri ile Diskapi yerleskesindeki yonca ekim alanlarindaki onemli hastaliklar belirlenmistir. 2003 - 2004 yillarinda belirtilen bolgelerden ornekler alinarak hastalik etmenlerinin teshisleri yapilmistir. Teshisi yapilan funguslar; Leptotrochila medicaginis, Pseudopeziza medicaginis, Leveillula taurica, Peronospora trifoliorum, Phoma medicaginis var. medicaginis, Colletotrichum trifolii, Stemphylium botryosum, Stagonospora meliloti, Leptosphaerulina briosian ve Rhizoctonia solani’ dir. Bu funguslardan en yaygini Phoma medicaginis var. medicaginis olarak bulunmustur. Leptosphaerulina briosiana ise Turkiye icin yeni tespit edilen bir fungustur. Yonca mozaik virusu de tespit edilmistir.