First Report of Tomato yellow leaf curl virus Infecting Common Bean (Phaseolus vulgaris) in Greece

Tomato yellow leaf curl is one of the most devastating virus diseases of tomato (Lycopersicon esculentum Mill) crops worldwide. Several whitefly-transmitted viruses are associated with the disease and all are assigned to the genus Begomovirus, family Geminiviridae. In Greece, Tomato yellow leaf curl virus (TYLCV) was first reported to infect greenhouse and open-field tomatoes in 2000 (2). During 2006, a survey was conducted in the southwestern part of Peloponnese (mainland) within the areas of Kyparissia and Filiatra (Perfecture of Messinia) to identify the prevalence and natural hosts of the disease. During this survey, yellow mosaic, severe leaf curling, and leaf crumple symptoms were observed in greenhouse bean plants (Phaseolus vulgaris) that were cultivated together with tomatoes showing typical TYLCV symptoms. In all affected greenhouses, the incidence of the disease ranged from 1 to 5% in beans and 90 to 100% in tomato plants. Both bean and tomato plants were highly infested with Bemisia tabaci (Gennadius) populations and produced unmarketable fruits. Twenty-four symptomatic bean plants were collected from four greenhouses that tested positive by triple-antibody sandwich-ELISA using TYLCV-specific antibodies purchased from NEOGEN, EUROPE, Ltd. DNA was extracted from all infected bean plants, and a 580-bp fragment of the coat protein gene was amplified by PCR using the TY(+)/TY(-) primer pair (1). Amplified fragments were then analyzed by restriction fragment length polymorphism with Ava II cutter enzyme. Two DNA fragments of 277 and 302 bp in agarose gels were produced from all isolates and the restriction pattern corresponded to TYLCV. The amplified DNA from four infected bean plants was cloned and sequenced. All four sequences were 100% identical (EMBL Accession No. AM418398) and showed 99% nucleotide identity to a TYLCV isolate from Italy (EMBL Accession No. DQ144621). To our knowledge, this is the first report of TYLCV infection of P. vulgaris, which is an important commercial crop in Messinia, Greece. Within the last decade, TYLCV has emerged as an important pathogen for several cultivated plants in many regions and different TYLCV variants have been reported to infect P. vulgaris (3). Bean is often used as an intercrop between tomato crops, and thus, infected plants may serve as a potential reservoir for virus survival and spread (4). References: (1) G. P. Accotto et al. Eur. J. Plant Pathol. 106:179, 2000. (2) A. D. Avgelis et al. Plant Dis. 85:678, 2001. (3) J. Morris et al. EPPO Bull. 32:41, 2002. (4) J. Navas-Castillo et al. Plant Dis. 83:29, 1999.