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Root galling caused by Meloidogyne javanica (Javanese root-knot nematode) on Solanum viarum (tropical soda apple)
Photograph courtesy of J. Lotz and J. A. Brito, DPI

Solanum viarum (tropical soda apple)
Photograph courtesy of J. Jeffrey Mullahey, University of Florida, Bugwood.org

Nematology Section

Compiled by Janete A. Brito, Ph.D., and Renato N. Inserra, Ph.D.

This Section analyzes soil and plant samples for nematodes, conducts pest detection surveys and provides diagnosis of plant problems, in addition to completing identification of plant parasitic nematodes involved in regulatory and certification programs. State of Florida statutes and rules mandate the principal part of the regulatory activity of the section. Analyses of plant and soil samples include those from in-state programs, plant shipments originating in Florida destined for other states and countries, as well as samples intercepted in Florida from outside the United States.

Nematodes of Special Interest

Solanum viarum (tropical soda apple) - Meloidogyne javanica (Treub, 1885) Chitwood, 1949, the Javanese root-knot nematode was found infecting the roots of this noxious weed during a survey by DPI staff. Roots were heavily infected and deformed by prominent, bead-like galls. In November 1994, this species was found on tropical soda apple in Walton County and reported in TRI-OLOGY. At that time, it was noted that "unlike cultivated crops, tropical soda apple was not severely damaged by the population of Javanese root-knot nematode." A root-knot nematode in the same genus (M. arenaria) was recently reported on tropical soda apple with a similar concern that the plant will serve as a reservoir for a known pest of garden tomatoes and many other hosts. Although these species of root-knot nematodes have been found reproducing on the tropical soda apple, they are not biological control agents and should not be used as such. Root-knot nematodes have broad host ranges and are very damaging pathogens of many agronomic and horticultural crops including most row and vegetable crops, fruit trees and ornamental plants. DPI continues its active monitoring of this and other pest plants. (Volusia County, N09-00100, Kenneth L. Hibbard, 28 January 2009; Lake County, N09-00170, Leslie J. Wilbur, 11 February 2009.) (Church and Rosskopt 2005; Inserra, R.N. 1994; http://www.gri.msstate.edu/research/ipams/ipams.php.) (DPI circular No. 27 - Tropical Soda Apple Solanum viarum)

Miscanthus sinensis (zebra grass, Chinese silver grass) - Pratylenchus zeae Graham, 1951, a root lesion nematode was found infecting the roots of this ornamental grass. Nematode-infected roots showed dark lesions on their surface. Morphological and molecular (rDNA) analyses were used for species identification. As this ornamental grass becomes more popular in Florida, its pests may become more economically important. (Santa Rosa County, N09-00152, William L. Robinson, 5 February 2009.)

References

• Church, G. T. and E. N. Rosskopt. 2005. First report of the root-knot nematode Meloidogyne arenaria on tropical soda apple (Solanum viarum) in Florida. Plant Disease 89: 527.
• Inserra, R.N. 1994. Nematology section. TRI-OLOGY 33: 7.

Collectors submitting five or more samples that were processed for nematological analysis in January - February 2009