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A serious outbreak of a leaf spot disease was observed on tomato transplants grown in commercial seedling companies in southwestern Turkey (Antalya) during the springs of 2002 and 2003. Disease incidence was more severe in the western Mediterranean Region of Turkey. Occurrence of the outbreak resulted in approximately 20 and 25% seedling losses in the springs of 2002 and 2003, respectively. The initial symptoms consisted of pronounced water-soaked, dark brown-to-black spots on young expanding leaves that were 1 to 2 mm in diameter. Later, a number of leaf spots on older leaves enlarged and coalesced, causing leaf desiccation and finally, seedling death. In addition, in 2003 the disease incidence was approximately 5% in 142 commercial greenhouses. Tomato production was unaffected since significant outbreaks did not occur on greenhouse plants. No fruit symptoms were observed. Twenty-six strains were isolated from diseased tomato seedlings and plants from different greenhouses located in different places and all were gram negative and fluorescent on King's B medium. All strains were levan and gelatin liquefaction positive and oxidase and arginine dihydrolase negative. None of the 26 strains utilized erythritol and l-lactate as the sole carbon source (1,2). Fatty acid analysis identified the strains as Pseudomonas syringae pv. tomato with similarity indices ranging from 0.876 to 0.932%. Pathogenicity of the isolates was confirmed on 4-week-old tomato seedlings (cv. Biotek Selin) sprayed with the bacterial suspensions containing 108 CFU/ml of sterile water. Later, a number of leaf spots on the leaves enlarged and coalesced, causing leaf desiccation. Inoculated and control tomato seedlings were covered with polyethylene bags and placed in a growth chamber at 25°C for 48 h and then the bags were removed. Small (1 to 2 mm), water-soaked, dark brown-to-black spots similar to those observed in the greenhouses of commercial seedling companies and commercial greenhouses that produce tomato developed on the young expanding leaves of inoculated plants within 7 to 10 days. No symptoms developed on control plants. The bacterium was reisolated from inoculated plants and identified as a strain of Pseudomonas syringae pv. tomato. Koch's postulates were fulfilled. To our knowledge, this is the first report for the occurrence and outbreak of the bacterial speck disease on tomato transplants in greenhouses of commercial tomato seedling production companies in Turkey. References: (1) D. C. Hildebrand et al. Pages 60–80 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. N. D. Schaad, ed. The American Phytopathological Society, 1988. (2) J. B. Jones et al. Plant Dis. 70:151, 1986.

Xanthomonas axonopodis pv. vesicatoria, causal agent of bacterial spot of tomato (Lycopersicon esculentum L.) and sweet pepper (Capsicum annuum L.) was isolated from tomato and pepper plants in greenhouse production in the Province of Antalya, in southwestern Turkey. Disease incidence was less than 4% of plants observed in 2001 and ranged from 1 to 20% in 2002. Eleven seedling-producing companies and 26 greenhouses that produce tomato and pepper were surveyed during the rainy seasons of 2001 and 2002. The increase in disease incidence in 2002 is an indication that this disease is becoming more prevalent on tomato and pepper plants grown in greenhouses in southwestern Turkey. A gram-negative bacterium producing yellow-pigmented colonies on nutrient agar was consistently isolated from brown, circular spots on leaflets of tomato and sweet pepper seedlings. Five isolates were pathogenic on commercial cultivars of tomato and pepper when bacterial suspensions (108 CFU/ml) were infiltrated into the intercellular spaces of leaves to determine race by using procedures described by Bouzar et al. (1). All the isolates produced hypersensitive reaction responses on tomato genotype cv. Hawaii 7998 and pepper genotype cvs. 20 R and 30 R and were designated tomato race 1 pepper race 1 (T1P1) (1). Fatty acid analysis of the strains identified them as X. axonopodis vesicatoria with similarity index values of 0.872 to 0.933. In addition, the strains were tested with X. axonopodis vesicatoria-specific polymerase chain reaction primers (RST 2/3 and RST 9/10) (2). The isolates were determined to be X. axonopodis vesicatoria. Although bacterial spot of tomato has been suspected in Turkey for a number of years, to our knowledge, this is the first report of the bacterium on tomato. References: (1) H. Bouzar et al. Phytopathology 84:663, 1994. (2) R. P. Leite, Jr. et al. Appl. Env. Microbiol. 60:1068, 1994.

The essential oil of Rosa damascena petals was evaluated for its antibacterial effects against three strains of Xanthomonas axonopodis spp. vesicatoria. The essential oil may be a potential control agent in the management of the disease caused by X a. vesicatoria in tomato and pepper plants. (C) 2003 Elsevier Science B.V. All rights reserved.

During the 2003 winter growing season, a disease occurred on tomato (Lycopersicon esculentum L.) cvs. Selin, Astona, 198 RN, Malike, and Tulin that were growing in almost all greenhouses of Serik, Aksu, Kumluca, Demre, and Kinik in the Antalya Province, and Keçiborlu, Çandir, and Şeyhler in the Isparta Province in the western Mediterranean Region of Turkey. Disease incidence ranged from 26 to 65%, resulting in economically heavy losses. Symptoms were water-soaked, dark brown-to-black lesions on the leaf margins and asymmetrical wilting of the leaflets. In advanced stages of disease, vascular tissue had a light brown discoloration. A gram-positive bacterium was consistently isolated and formed light gray colonies with internal light gray flecks approximately 2 to 3 mm in diameter on the modified semiselective medium (SCM) (2). Thirty isolates were identified as Clavibacter michiganensis subsp. michiganensis using polymerase chain reaction (PCR) with primers CMM 5 and CMM 6 on the basis of consistent amplification of a 614-bp DNA fragment (1). The isolates were also identified as C. michiganensis subsp. michiganensis (similarity 0.810 to 0.888%) using fatty acid methyl ester (FAME) analysis and Sherlock Microbial Identification System software (Microbial ID, Newark, DE). A pathogenicity test was done by spraying a 6-week-old tomato seedling (cv. Selin) with the bacterial concentration of 108 CFU/ml in sterile water. Control tomato seedlings were only sprayed with sterile water. The inoculated plants were covered with polyethylene bags for 48 h and kept in a growth chamber at 25°C. Symptoms developed on the inoculated plants within approximately 10 days and were similar to those observed in the greenhouse. No symptoms developed on control plants. The bacterium was reisolated from inoculated plants, and its identity was confirmed by colony type on SCM, PCR, and FAME analysis. Although it has been known to be present previously in Aegean, eastern Mediterranean, and the eastern Anatolia regions of Turkey, to our knowledge, this is the first report of bacterial canker on greenhouse tomatoes in the western Mediterranean Region of Turkey. Occurrence of the disease in almost all greenhouses may be the result of the high relative humidity present and the lack of protective bactericide applications in many greenhouses of the region. References: (1) J. Dreier et al. Phytopathology 85:462, 1995. (2) M. Fatmi and N. W. Schaad. Phytopathology 78:121, 1988.