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 eriği) 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.
