Rev 12/16/2024
Review general characteristics of the genus Meloidogyne.
Second-stage juvenile
Meloidogyne floridensis was first found on Nemaguard, Nemared and Okinawa peach rootstocks in Gainesville, Florida in 1966. The rootstocks are resistant to M. incognita and M. javanica. The nematode was first assumed be a race of Meloidogyne incognita, but host range tests (Nyzcepir et al., 1998) suggested otherwise. Molecular studies confirm that M. floridensis differs from M. incognita and other root-knot nematodes (Handoo et al, 2004).
Esterase patterns of M. floridensis differed from all other root-knot nematodes tested (Handoo et al, 2004)
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Florida, USA. Recently found on "resistant" peach rootstocks in Merced and Kern Counties, California. Also on Thompson Seedless grape (personal communication John Chitambar CDFA, 2018). Also reported from Georgia and South Carolina in the USA.
The peach root-knot nematode was detected in Merced County, California on a Prunus rootstock known to be resistant to M. incognita (Chitambar (2018; Westphal et al., 2019).
Meloidogyne floridensis infests and reproduces on root knot nematode resistant Nemaguard, Nemared and Okinawa peach rootstocks. (Westphal et al., 2019). It has also been reported on Guardian peach roostock, also resistant to M. incognita and M. javanica, in South Carolina, USA ( Reighard et al., 2019).
A-rated, quarantined pest in California.
The finding of M. floridensis in California triggered research to determine whether that isolate is virulent on tamato with the Mi-1 gene and on Melodigyne resistant sweet potato cultivars. Also, to determine whether the isolate can overcome resistance in other vegetable crops. Ploeg and Edwards (2024) compared the reproduction and root-galling of the California isolate of M. floridensis to an M. incognita race-3 isolate on M. incognita-susceptible and -resistant tomato, pepper, and cowpea. Although no resistant cultivars are available, melon and carrot were included because their host status for M. floridensis is unknown, and they are important RKN-susceptible vegetable crops in California. Cotton was included as an important non-vegetable crop with RKN-resistant cultivars available.
Sedentary endoparasite.
Feeding site establishment and development typical of genus.
Type Host: Peach (Prunus persica)
Nemaguard, Nemared and Okinawa peach rootstocks (Prunus persica), watermelon and tomato are hosts. Myrobalan plum and peppers are non-hosts (Handoo et al, 2004).
The finding of M. floridensis in California triggered research to determine whether that isolate is virulent on tomato with the Mi-1 gene and on Meloidogyne-resistant sweet potato cultivars. Also, to determine whether the isolate overcomes resistance in other vegetable crops. Ploeg and Edwards (2024) compared the reproduction and root-galling of the California isolate of M. floridensis to an M. incognita race-3 isolate on M. incognita-susceptible and -resistant tomato, pepper, and cowpea. Although no resistant cultivars are available, melon and carrot were included because their host status for M. floridensis is unknown, and they are important RKN-susceptible vegetable crops in California. Cotton was also included in the stydy. They concluded that M. floridensis reproduces on most vegetable crops, including some cultivars that are resistant to M. incognita. However, on susceptible crops, the reproduction of M. floridensis was always significantly less than that of M. incognita.
Ecophysiological Parameters:
Haploid chromosome number n=18, 19, 20; reproduction is by facultative meiotic parthenogenesis. The egg nucleus undergoes a meiotic reduction division; one member of each pair of chromatids remains in a haploid nucleus and the other in a polar body. If fertilization by a male sperm occurs, the diploid number of chromosomes is restored. Otherwise the somatic number of chromosomes is restored by fusion of the egg pronucleus with the polar body from the reduction division (Handoo et al., 2004; Subbotin et al., 2021; Triantaphyllou, 1985).
Host Plant Resistance, Non-hosts and Crop Rotation alternatives:
Ploeg and Edwards (2024) concluded that M. floridensis is virulent on M. incognita-resistant pepper and tomato, and, to a lesser extent, cowpea.
Brito, J. A., Dickson, D. W., Kaur, R., Vau, S., and Stanley, J. D.. 2015. The peach root-knot nematode: Meloidogyne floridensis, and its potential impact for the peach industry in Florida. Nematology Circular 224: 7.
Chitambar, J. 2018. Meloidogyne floridensis Handoo et al., 2004. https://blogs.cdfa.ca.gov/ Section3162/?p=5666
Handoo, Z.A., A.P. Nyczepir, D. Esmenjaud, J.G. van der Beek, P. Castagnone-Sereno, L.K. Carta, A.M. Skantar and J.A. Higgins, 2004. Morphological, molecular, and differential host characterization of Meloidogyne floridensis n.sp. (Nematoda: Meloidogynidae), a root-knot nematode parasitizing peach in Florida. J. Nematology 36:20-35.
Nyczepir, A.P., D. Esmenjaud and J.D. Eisenback. 1998. Pathogenicity of Meloidogyne sp. (FL isolate) on Prunuus in the southeastern United States and France. J. Nematology 30: 509.
Ploeg, A.T., Edwards, S. 2024. Host status of melon, carrot, and Meloidogyne incognitasusceptible and -resistant cotton, cowpea, pepper, and tomato for M. floridensis from California. J. Nematology 56: DOI: 10.2478/jofnem-2024-0004
Reighard, G.L., Henderson, W.G., Scott, S.O., Subbotin, S.A. 2019. First Report of the Root-Knot Nematode, Meloidogyne floridensis Infecting Guardian Peach Rootstock in South Carolina, USA. J. Nematology 51: DOI: 10.21307/jofnem-2019-061
Subbotin, S.A. Palomares-Rius, J.E., Castillo, P. 2021. Systematics of Root-knot Nematodes (Nematoda: Meloidogynidae). Nematology Monographs and Perspectives Vol 14: D.J. Hunt and R.N. Perry (eds) Brill, Leiden, The Netherlands 857p.
Triantaphyllou, A.C. 1985. Gametogenesis and the chromosomes of Meloidogune nataliei: not typical of other root-knot nematodes. J. Nematology 17:1-5.
Triantaphyllou, A.C. 1985. Cytogenetics, cytotaxonomy and phylogeny of root-knot nematodes. In Sasser, J.N. & Carter, C.C. (eds) An Advanced Treatiswe on Meloidogyne.Vol 1. Biology and Control.N.C. State Universty Graphics, Raleigh, N.C. USA.
Westphal,W., Zin T. Z. Maung, David A. Doll, Mohammad A. Yaghmour, John J. Chitambar, Sergei A. Subbotin. 2018. First Report of the Peach Root-Knot Nematode, Meloidogyne floridensis Infecting Almond on Root-Knot Nematode Resistant Hansen 536 and Bright's Hybrid 5 Rootstocks in California, USA. J. Nematology DOI: 10.21307/jofnem-2019-002