Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 15, 2004
Publication Date: April 1, 2005
Citation: Church, G.T. 2005. First report of the root-knot nematode Meloidogyne floridensis on tomato (Lycopersicon esculentum) in Florida. Plant Disease. 89:527. Technical Abstract: The state of Florida is the largest producer of fresh market tomato (Lycopersicon esculentum L.) in the United States, with 2003 yields of 634 million kg, on 17,700 hectares, valued at 516 million dollars (4). Effective crop management is essential for production of vegetables in Florida due to the presence of intense pest pressure. The identification of the pests present is the first step in the development of a successful IPM program. Root-knot nematodes (Meloidogyne spp.) are the most common nematodes that parasitize vegetables in Florida and cause significant yield reductions when not properly managed. In 2003 field experiments, soil was collected from two research farms in Saint Lucie and Seminole counties in Florida. Galling caused by root-knot nematode was observed on tomato at both locations. Since females suitable for identification are difficult to obtain from field-grown roots, field soil was placed in pots in the greenhouse and planted with Lycopersicon esculentum cv. Rutgers. Female root-knot nematodes were extracted from the roots of each isolate and placed in extraction buffer (10% wt/vol sucrose, 2% vol/vol Triton X-100, 0.01% wt/vol bromophenol blue). The females were crushed, loaded on a polyacrylamide gel and separated by electrophoresis using the PhastSystemTM (Amersham Biosciences) (1). The activities of malate dehydrogenase and esterase enzymes were detected using standard techniques (3). Banding patterns consistent with Meloidogyne incognita (Kofoid and White) Chitwood and M. javanica (Treub) Chitwood were observed at both locations. However, another banding pattern that was observed was inconsistent with any known Meloidogyne species. After further investigation the banding pattern was identical to the newly described Meloidogyne floridensis Handoo (2). This is the first report of M. floridensis naturally occurring on tomato in Florida. The identification and distribution of M. floridensis in vegetable production fields is important for disease management throughout the state since the host range is different from other Meloidogyne species.