Submitted to: Nematropica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2007
Publication Date: 6/1/2007
Citation: Cetintas, R., Kaur, R., Brito, J.A., Mendes, M.L., Nyczepir, A.P., Dickson, D.W. 2007. Pathogencity and reproductive potential of Meloidogyne mayaguensis and M. floridensis compared with three common Meloidogyne spp. Nematropica. 37:21-31. Interpretive Summary: Tomato is an important vegetable crop in Florida. The root-knot nematode is an important pathogen on tomato if proper management practices are not followed. Meloidogyne mayaguensis is a highly virulent root-knot nematode recently reported infecting different horticultural and ornamental plants in Florida. However, its pathogenicity status on tomato is unknown relative to other common root-knot nematode species. Determining the pathogenicity of M. mayaguensis relative to other root-knot species in Florida needs to be investigated. Microplots were infested with two levels of each of the Peanut, Southern, Javanese, Peach, and A Root-Knot Nematode planted to Solar-Set tomato. Eighty-two days after inoculation, results indicate that tomato infested with A Root-Knot Nematode (i.e., M. mayaguensis) had a greater percentage of galls and eggs than most of the other species evaluated. The size of the galls produced by this nematode was also much larger. These data provide useful insights into the pathogenicity of M. mayaguensis on tomato which will be very important in the development of appropriate nematode management strategies.
Technical Abstract: The pathogenicity and reproductive potential of Meloidogyne mayaguensis and M. floridensis, two new species reported in Florida agriculture, were compared to those of M. arenaria race 1, M. incognita race 4, and M. javanica race 1 on tomato (Lycopersicon esculentum Mill.) in field microplots. Two trials were conducted in fall and spring seasons using tomato cvs. Solar Set and Florida 47, respectively and one trial in spring season with cv. Florida 47. Two levels of each nematode (low = one egg or second-stage juvenile (J2)/100 cm3 of soil; high = three eggs or J2/100 cm3 of soil) were used with nine replicates each. Common vetch (Vicia sativa L.) was used in trial one as a winter cover crop. Nematode densities in the soil, root-galling, eggs per gram fresh root, shoot fresh weight and plant height were recorded. No significant interaction was observed between root-knot nematode species and inoculum levels in trials one or two except for eggs per gram of fresh root and J2 per 100 cm3 of soil at harvest of Solar Set in trial one, fall 2004. All five species of root-knot nematodes induced root-galling and reproduced well on both tomato cultivars, except M. floridensis, which produced less galling in all trials. M. mayaguensis produced the highest percentage of root-galling on Solar Set in the fall trial but not on Florida 47 in spring trials. However, M. arenaria showed a higher reproductive potential on Solar Set in fall trial. Galling on vetch was equal among M. arenaria, M. incognita, M. javanica, and M. mayaguensis, but number of J2 in soil were lower for M. floridensis and M. javanica than for M. arenaria, M. incognita, and M. mayaguensis. In summary, although M. mayaguensis showed a propensity to be more virulent than the other root-knot nematode species by inducing strikingly large galls on tomato the nematode only caused greater fruit yield reduction in one of two trials in spring of 2005. On the other hand M. floridensis showed a propensity for inducing fewer galls on tomato than the other four species of root-knot nematodes.