First Report from Turkey of European Plum Line Pattern Caused by Apple mosaic virus.

European plum line pattern was first described in Bulgaria (1) and can now be found nearly worldwide. Characteristic symptoms in infected plum (Prunus domestica) include line and oak leaf patterns with chlorotic lines and rings in leaves. The causal agent of this economically damaging plum disease is Apple mosaic virus (ApMV). ApMV has been reported to naturally infect a number of hosts in the Rosaceae, including Rosa, Malus, and Rubus spp. as well as Humulus, Betula, and Corylus spp. in other plant families (3), but has not been reported to naturally infect plum in Turkey. In this study, disease symptoms were observed in only one local cultivar (Süt erigi) during the growing season of 2008-2009 in Amasya and Tokat provinces, situated between the Black Sea and inner Anatolia regions. Leaf samples were collected from 22 plum trees and tested by serological and molecular methods. In serological tests, double-antibody sandwich-ELISA was used with antisera to ApMV and Prunus necrotic ringspot virus (PNRSV) according to the manufacturer's (Agdia, Inc., Elkhart, IN) protocol. While none of the samples reacted positively to PNRSV antisera, 19 samples reacted positively to ApMV antisera. The presence of ApMV in symptomatic plum trees was confirmed by reverse transcription (RT)-PCR. RT-PCR was conducted with ApMV-specific primers (Forward 5'-ATCCGAGTGAACAGTCTATCCTCTAA-3'; reverse 5'-GTAACTCACTCGTTATCACGTACAA-3') as previously described (4) to specifically amplify a 262-bp product from viral sequences. Total RNA was extracted from plum leaf samples with a modified protocol based on silica-capture (2). Using serological and RT-PCR tests, ApMV was detected in all 19 samples that showed virus symptoms, but not from symptomless plants. To our knowledge, this is the first record of the presence of European plum line pattern in Turkey and provides a starting point for investigation of the incidence of ApMV in plum orchards of Turkey. References: (1) D. Atanasoff et al. Phytopathol. Z. 8:197, 1935. (2) X. Foissac et al. Acta Hortic. 550:37, 2001. (3) R. W. Fulton. CMI/AAB Descriptions of Plant Viruses. No. 83. 1972. (4) W. Menzel et al. J. Virol. Methods 99:81, 2002.

Widespread Distribution of Apple mosaic virus on Apple in Turkey.

From 2002 to 2003, symptoms suggestive of Apple mosaic virus (ApMV; a member of the genus Ilavirus) infection on apple (Malus pumila L.) trees were observed in orchards in the central Anatolia Region of Turkey. Symptoms on leaves included pale-to-bright cream spots, mosaic, and yellowing on the leaves. A survey was conducted during May and June in three provinces (Isparta, Karaman, and Nigde) for disease symptoms. Leaf samples from apple cvs. Anna, Gala, Gold Star, Golden Delicious, Granny Smith, Jonathan, Starking, and Rajka were collected and tested for the presence of ApMV with specific antisera (Agdia, Elkhart, IN) using the manufacturer's protocol for double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). ApMV was found in 68.3% of 461 samples tested. The number of samples for each cultivar tested and percent positive for ApMV were as follows: 22 (9.1%), 34 (8.8%), 22 (13.6%), 30 (73.3%), 270 (95.5%), 46 (54.3%), and 22 (9.1%) for cvs. Anna, Gala, Gold Star, Golden Delicious, Granny Smith, Starking, and Rajka, respectively. All 15 samples tested of cv. Jonathan were negative using DAS-ELISA. Samples that tested positive for ApMV were mechanically inoculated onto Chenopodium amaranticolor, C. quinoa, and Cucumis sativus leaves using an inoculum prepared by homogenizing leaves in phosphate buffered saline containing 2.5% (vol/vol) nicotine. Inoculated C. quinoa showed inconspicuous mottling, and Cucumis sativus showed chlorotic local lesions that progressed to systemic chlorosis and stunting. No symptoms were observed on inoculated C. amaranticolor as previously reported for ApMV (3,4). The presence of ApMV in C. quinoa and Cucumis sativus were verified using DAS-ELISA, but ApMV was not detected in C. amaranticolor. Although ApMV has been reported in several different crops in Turkey, there have been only two unsubstantiated reports of ApMV-infected apple in the country (1,2). This study conclusively demonstrates ApMV infection of apples in Turkey and suggests that it is widely spread. References: (1) Ü. Fidan. J. Turk. Phythopathol. 23:3, 127, 1994. (2) M. Özkan and S. Kurçman. Bitki Koruma Bül. 16:106, 1976. (3) S. J. Petybridge et al. Ann. Appl. Biol. 141:77, 2002. (4) T. Sano et al. Ann. Appl. Biol. 106:305, 1985.