Disease Note.

First Report of a Tomato Yellow Leaf Curl-Like Geminivirus in the Western Hemisphere. J. E. Polston, University of Florida, Gulf Coast Research and Education Center, 5007 60th St E., Bradenton 34203. D. Bois, University of Florida, Gulf Coast Research and Education Center, 5007 60th St E., Bradenton 34203, and C.-A. Serra and S. Concepcion, Instituto Superior de Agricultura, Apartado 166, Santiago, Dominican Republic. Plant Dis. 78:831. Accepted for publication 3 May 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-0831B.

A new disease of processing tomato [Lycopersicon esculentum Mill.) was first observed in the northwestern Dominican Republic in fall 1992. Symptoms in affected plants resembled those induced by tomato yellow leaf curl virus (TYLCV) and included flower abscission; severe stunting; and in leaves, extreme size reduction, curling, cupping, and marginal chlorosis. In fall 1993, tomatoes in the northwestern and southern production areas were affected, with losses estimated at 90%. Disease incidence was 80-100% in plantings at least I mo old. High populations of (he whitefly Bemisia argentifolli Bellows & Perring, which first appeared in the Dominican Republic in 1989, were associated with symptomatic plants. Symptoms seen in the field were reproduced in the greenhouse via whitefly transmission from affected plants to healthy tomatoes. Spot hybridization assays (I) of plants from both production areas were conducted with tomato motile virus (ToMoV) A component and TYLCV (courtesy of Y. Antignus) DNA probes. The ToMoV A DNA hybridized weakly with the samples, but strong hybridization was observed with the TYLCV DNA probe. Nucleic acid extracts of samples were amplified using A component (PALlvI978 and PARlc496) and B component (PBLlv2040 and PCRcl) specific degenerate primers (2). Whitefly-transmitted bipartite geminiviruses tested to date with these two sets of primers yield ca. 1,100- and 600-bp fragments, respectively. With the Dominican Republic samples, a DNA fragment ca. 1,400 bp was amplified using A component primers, and a ca. 400-bp fragment was weakly amplified using B component primers. Amplification of TYLCV with A and B component primers yielded a ca. 1,400-bp fragment and no visible fragment, respectively. Restriction of the ca. 1,400-bp fragment from Dominican Republic samples with MspI, EcoRI, SacI, PstI, and BamHI gave a pattern not predicted from the published TYLCV sequences; and the product using B component primers is under study. These results indicate the disease in the Dominican Republic is caused by a TYLCV-like geminivirus, and this is the first report of this type of geminivirus in the Western Hemisphere.