Meloidogyne incognita

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Meloidogyne incognita
A juvenile root-knot nematode (Meloidogyne incognita) penetrates a tomato root - USDA-ARS.jpg
Scientific classification
Kingdom: Animalia
Phylum: Nematoda
Class: Secernentea
Order: Tylenchida
Family: Heteroderidae
Genus: Meloidogyne
Species: M. incognita
Binomial name
Meloidogyne incognita

Meloidogyne incognita is a species of nematodes (roundworms) in the family Heteroderidae. It is commonly called the "southern root-knot nematode" or the "cotton root-knot nematode". This parasitic roundworm has worldwide distribution and numerous hosts. It is an important plant parasite classified in parasitology as a root-knot nematode, as it prefers to attack the root of its host plant.

When M. incognita attacks the roots of plants, it sets up a feeding location, where it deforms, (destroys) the normal root cells and establishes giant cells. The roots become gnarled or nodulated (knobbly, rough, and twisted), forming galls, hence the term "root-knot" nematode.

M. incognita has been found to be able to move along shallower temperature gradients (0.001C/cm) than any other known organism,[1] an example of thermotaxis. The response is complicated and thought to allow the nematodes to move toward an appropriate level in soil,[2] while they search for chemical cues that can guide them to specific roots.[3][4][5]

The life cycle has four juvenile stages and four moults (shed, cast).

See also[edit]


  1. ^ Pline, Diez, and Dusenbery, J. Nematology, 20:605-608 (1988). Extremely sensitive thermotaxis of the nematode Meloidogyne incognita.
  2. ^ Dusenbery, D.B. Biological Cybernetics, 60:431-437 (1989). A simple animal can use a complex stimulus pattern to find a location,
  3. ^ Pline and Dusenbery. 1987. Responses of the plant-parasitic nematode Meloidogyne incognita to carbon dioxide determined by video camera-computer tracking. J. Chem. Ecol. 13 : 873-888.
  4. ^ Dusenbery. 1987. Theoretical range over which bacteria and nematodes locate plant roots using carbon dioxide. J. Chem. Ecol. 13 : 1617-1624.
  5. ^ Diez and Dusenbery. 1989. Repellent of root-knot nematodes from exudate of host roots. J. Chem. Ecol. 15:2445-2455.

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