Review general characteristics of the genus Meloidogyne.
Meloidogyne fallax is morphologically similar to the Columbia
root-knot nematode (M. chitwoodi). It differs
from M. chitwoodi in that males and females have longer stylets and that
the J2 has a longer tail and hyaline portion.
The species can be separated by biochemical and molecular techniques: isozyme
patterns esterase and malate dehydrogenase, fatty acid binding protein, and
species-specific primers (Karssen, 1994; Peterson et al., 1997; Tastet et al.,
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Belgium, France, Germany and the Netherlands, Australia, New Zealnd,
the United States and South Africa ( CAB International, 2001; Nobbs et al.,
2001; Elling, 2013; Fourie
et al., 2002).
Occurs in the U.S., reproted from golf course greens (Nischwitz et al.,
Its most important agronomic host is potato, in which it can cause total
yield losses due to quality defects and imposition of quarantines (Elling,
Feeding site establishment and
development typical of genus.
Type host: tomato (Solanum lycopersicum)
Meloidogyne fallax has some hosts in common with M. chitwoodi: alfalfa (Medicago
sativa), carrot (Daucus carota), potato (Solanum tuberosum),
sugarbeet (Beta vulgaris), and tomato (Solanum lycopersicum).
Hosts not shared with M. chitwoodi include: hemerocallis (Hemerocallis
sp.), Dicentra spectabilis, Oenothera erythrosepala, and
Other differential hosts which are infected by M. chitwoodi but not by
M. fallax are bean (Phaseolus vulgaris) and corn (Zea mays).
The following hosts of M. fallax but not reported for M.
chitwoodi are artichoke (Cynara scolynus), lettuce (Lactuca sativa),
and oyster plant (Scorzonera hispanica).
More information is needed on the host status of cereals to M. fallax.
Haploid chromosome number n=18; reproduction is by facultative
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 (Subbotin
et al., 2021; Triantaphyllou, 1985; Van der Beek & Karssen, 1997).
The nematodes cause small, round galls at root tips. Females produce egg
masses protruding from the root surface (CAB International, 2001; EPPO, 2001).
M. chitwoodi, the
major damage by M. fallax on potato tubers
a nematode-induced blemish which lowers or negates their marketability. Both
species incite small galls, typically without secondary roots, and can lead to
stunting and yellowing aboveground.In potato tubers, they cause numerous
small pimple-like swellings
M. fallax is considered as closely related to M. chitwoodi;
the two species can hybridize and produce viable F1 progeny under greenhouse
conditions (Elling, 2013)
Dispersed through root material, soil debris and by poorly sanitized seed
potatoes and bare root propagative material.
Host Plant Resistance, Non-hosts
Quantitative PCR methods indicate potential for predicting yield loss in
potato from M. fallax DNA measured in soil at planting and harvest (Hay
et al., 2016).
CAB International. 2001. Meloidogyne fallax in Crop protection
compendium, global module, 3rd editon. Wallingford, UK: CAB International.
Elling, A.A. 2013. Major Emerging Problems with Minor Meloidogyne
Species. Phytopathology 103:1092-1102.
Epppo. 2001. Epppo PQR Database. Paris France.
Fourie, H., C. Zijlstra, A.H. McDonald
and G. A. Venter. 2002. Advances in applied nematode research in South
Africa after introduction of the SCAR-PCR technique for nematode identification.
M. Hartley, and Sarah
J. Pethybridge. 2016. Prediction of Potato Tuber
Damage by Root-Knot Nematodes using Quantitative DNA Assay of Soil. Plant
Karssen, G. 1995. Morphological and biochemical differentiation in
Meloidogyne chitwoodi populations in the Netherlands. Nematologica
Nischwitz, N., A. Skantar, Z.A. Handoo, M.N. Hult, M.E.
Schmitt, and M.A. McClure. 2013. Occurrence of Meloidogyne fallax in
North America, and Molecular Characterization of M. fallax and M.
minor from U.S. Golf Course Greens. Plant Disease 97:1424-1430.
Paterson D. J., and T. C. Vrain. 1996. Rapid identification of Meloidogyne
chitwoodi, M. hapla, and M. fallax using PCR primers to
amplify their ribosomal intergenic spacer. Fundamental and Applied Nematology
Society of Nematologists Regulatory Committee, 2002.
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
Tastet. C., F. Val, M. Lasage, L. Renault, L. Marche, M. Bpssis, and D.
Mignieri. 2001. Application of a putative fatty acid binding protein to
discriminate serologically the two European quarantine root-knot nematodes,
Meloidogyne chitwoodi and M. fallax, from other Meloidogyne
species. European Journal of Plant Pathology 107:821-832.
Triantaphyllou, A.C. 1985. Gametogenesis and the chromosomes of
Meloidogune nataliei: not typical of other root-knot nematodes. J.
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.
Van der Beek, J.G and Karssen, G. 1997. Interspecific hybridization of
meiotic parthenogenetic.Meloidogyne chitroodi and M. fallax. Phytopathology