MELOIDOGYNE SPP. INFECTING ORNAMENTAL PLANTS IN FLORIDA

Brito, J. A., R. Kaur, R. Cetintas, J. D. Stanley, M. L. Mendes, T. O. Powers, and D. W. Dickson. 2010. Meloidogyne spp. infecting ornamental plants in Florida. Nematropica 40:87-103. A total of 206 root samples were collected from ornamental plants growing in ornamental nurseries and various landscapes in Florida. Isozyme phenotypes, especially esterase (EST) and malate dehydrogenase (MDH) were the main methods used to identify the root-knot nematode species. When needed, the morphology of female perineal patterns, morphometric characters and mitochondrial DNA were used to aid in the identification. Six Meloidogyne spp., M. arenaria, M. floridensis, M. graminis, M. incognita, M. javanica and M. mayaguensis were found infecting ornamental plants in Florida. As previously reported EST activity was of highest diagnostic value to identify Meloidogyne spp. found in this study; however, MDH was helpful to distinguish M. mayaguensis and M. graminis from the other root-knot nematode species identified. Five new EST phenotypes were detected associated with 17 unidentified root-knot nematode populations. To our knowledge, this is the first report of ornamental plants in the genera Dracena and Hibiscus, and Ligustrum and Washingtonia being host of M. floridensis and M. mayaguensis, respectively. New plant species host records for M. mayaguensis were Ajuga reptans, Amaranthus tricolor, Buddleja davidii, Caryopteris x clandonensis, Clerodendrum x ugandense, Hibiscus grandiflorus, Lagerstroemia indica, Penta lanceolata, Plectranthus scutellarioides, and Solandra maxima.