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First Report of Meloidogyne mayaguensis on Angelonia angustifolia

Angelonia angustifolia, commonly known as ‘angelonia’, belongs to the family Scrophulariaceae. This plant is an ornamental frequently grown by home gardeners in Florida. Angelonia is a short, erect perennial with smooth stems, narrow leaves with toothed margins, and long-lasting, colorful blooms that makes it an ideal summer bedding plant. Roots from angelonia plants that showed stunted growth and yellowing leaves while growing in a home garden in Alachua County were collected and sent to the Florida Department of Agriculture and Consumer Services Nematology Laboratory. The roots were heavily galled but the galls were very small. Females and second-stage juveniles (J2) were extracted from the galled roots and used for species identification on the basis of perineal patterns, J2 morphometrics, and electrophoresis of isozymes (esterase and malate dehydrogenase). Isozymes were extracted from young egg-laying females with extraction buffer (10% [wt/vol] sucrose, 2% [vol/vol] triton X-100, 0.01% [wt/vol] bromophenol blue) and resolved with polyacrylamide gel electrophoresis (4% stacking [pH 6.8] and 8% separating gel [pH 8.8] with Tris-glycine buffer) in the BioRad Mini Protean system. Morphology of the perineal patterns and measurements of the J2s matched those of the original description (3). Enzyme analyses showed two major bands (VS1-S1 phenotype) of esterase (Est) activity and one strong malate dehydrogenase (Mdh) band (N1a). The Est and Mdh phenotypes were consistent with those for M. mayaguensis reported earlier in Florida (1) and Brazil (2). Studies are currently underway regarding the identification and distribution of M. mayaguensis in ornamental nurseries and vegetable-producing areas in Florida. These surveys will provide insight for the implementation of regulatory and control measures. To our knowledge, this is the first report of A. angustifolia as a host of M. mayaguensis.

References: (1) J. A. Brito et al. J. Nematol. 36:232, 2004. (2) R. M. D. G. Carneiro et al. Nematology 2:645, 2001. (3) A. Rammah and H. Hirschmann. J. Nematol. 20:58, 1988.