Widespread Occurrence of the Eastern Mediterranean Strain of Tomato Yellow Leaf Curl Geminivirus in Tomatoes in the Dominican Republic. M. K. Nakhla, University of Wisconsin, Madison 53706. D. P. Maxwell, University of Wisconsin, Madison 53706 R. T. Martinez, Secretaria de Estado de Agricultura, San Cristobal, Dominican Republic and M. G. Carvalho and R. L. Gilbertson, University of California, Davis 95616. Plant Dis. 78:926. Accepted for publication 14 June 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-0926D.
A virus disease epidemic devastated tomato (Lycopersicon esculentum Mill.) production in the Dominican Republic (Dom. Rep.) during the winter growing season of 1993-94. Infected plants were stunted, and leaves were small, upcurled, crumpled, and often had yellow margins. In many fields, nearly 100% of the plants showed symptoms, and many fields were abandoned due to the disease. In January and February 1994, symptomatic tomato plants and weeds with yellow mosaic or mottle symptoms were collected from tomato fields in north central (three fields), northwest (one field), and southwest (four fields) regions of the Dom. Rep. and analyzed for geminiviruses using nucleic acid squash blot hybridization (1). A general DNA probe for Western Hemisphere geminiviruses transmitted by Bemisia tabaci hybridized weakly with squash blots of all 19 tomato samples and a single Datura sp. sample showing leaf crumpling and yellow mottle symptoms, and strongly with squash blots of Euphorbia sp., Sida spp., Jatropha sp., and a control of tomato mottle geminivirus (ToMoV) from Florida. A 2.8-kb, full-length viral DNA fragment was amplified from DNA extracted from a symptomatic tomato collected near Bani, Dom. Rep., by PCR and primers PTYClv2182 and PTYClc2140, which overlap an Nco\ site of tomato yellow leaf curl virus (TYLCV-ISR) from Israel (2). The PCR fragment was digested with Nco\ and cloned into pGEM-5Zf+ to generate recombinant plasmid pTY-DRl. A partial nucleotide (nt) sequence of the intergenic region of the pTY-DRl insert was 97,66, and 55% identical to homologous regions of TYLCV-ISR (nt 1 to 265) (2), TYLCV from Sardinia, Italy (TYLCV-SAR, GenBank No. X61153). and ToMoV (GenBank No. L14460), respectively. Similarly, a partial sequence of the coat protein ORF of the pTY-DRl insert (nt position 857 to 1,034 of TYLCV-ISR) was 98, 79, and 69% identical to homologous sequences from TYLCV-ISR, TYLCV-SAR, and ToMoV, respectively. Under high stringency conditions, pTY-DRl hybridized strongly with squash blots of all 19 tomatoes and the Datura sp., and not with squash blots of the other weed samples or symptomless tomatoes and Datura sp. These findings indicate that the Eastern Mediterranean strain of TYLCV has been introduced into the Dom. Rep. and is widely distributed in the major tomato-growing regions.References: (I) R. L. Gilbertson et al. Plant Dis. 75:336. 1991 (2) N Navot et al. Virology 184:151, 1991.