Family MELOIDOGYNIDAE

                                 Rev. 12/16/24

Classification:

      Chromadorea


       Rhabditida
       Tylenchina
        Tylenchoidea
       

          Meloidogynidae Skarbilovich, 1959

Morphology and Anatomy:

• Cuticle not moderately thick, annulated in all stages of the male and female. 
• Cephalic framework low, with medium sclerotization; lateral sectors equal to or wider than submedian sectors. 
• Strong sexual dimorphism: females pear-shaped to globose, males vermiform

Female:

• Sedentary, globose with projecting neck. 
• No pre-adult vermiform female stage. 
• Cuticle moderately thick; annulation forming fingerprint-like pattern around vulva and anus.
• Labial disc dumb-bell shaped, not detached from labial sectors. 
• Cephalic framework and spear delicate. 
• Median esophageal bulb oval to spherical; esophageal glands overallping intestine ventrally and laterally
• Excretory pore anterior to median esophageal bulb, often only slightly posterior to stylet base. 
• Vulva and anus terminal; perineal region flush or slightly raised. 
• Didelphic, prodelphic, ovaries coiled
• Cuticle in anal aand vuval region with perineal patern like finger-print.
• No cyst stage. Eggs not retained in female body but deposited in a gelatinous matrix (exception: Meloidogyne spartinae where eggs are deposited individually without gelatinous matrix). 
• Very important damaging pathogens of plants.

Male:

• Labial area low, not set-off, irregularly annulated. 
• Lateral field with four lines. 
• Monorchic, testis outstretched
• Bursa usually absent
• Tail short or absent
• Body twisted through 90 degrees so that spicules and cloaca are on lateral of coiled male

Juveniles:

• Second-stage juveniles migratory, vermiform. 
• Cephalic framework and spear delicate. 
• Labial area not set-off. 
• Late second-stage sedentary, swollen (spike-tailed). 
• Third and fourth stages occurring within the second stage cuticle, devoid of stylet.

 Feeding Biology:

• Sedentary, causing galls on roots. 
• Incite multinucleate giant cells resulting from karyokinesis in the absence of cytokinesis.
• Suppress pathogen-triggered immunity (PTI) responses; a possible mol;ecule for effector-triggered suppression is chorismate mutase produced in the esophageal glands.  In PTI responses, chorismate is converted to salicylic acid to iniate the defense events.  Chorismate mutase from the nematode reduces chorismate, and thus salicylic acid (Smant and Jones, 2011).

References:

Luc, Maggenti & Fortuner, Rev. Nematol. 11:159-176 (1988).

Smant, G., Jones, J. 2011.  Suppression of plant defences by nematodes.  Chapter 13, pp 273-286. In Jones, J., Gheysen, G., Fenoll, C. (eds).  Genomics and Molecular Genetics of Plant-Nematode Interactions.  Springer, NY.

Subbotin, S.A., Palomares-Rius, J.E., Castillo, P. 2021.Systematics of Root-knot Nematodes (Nematoda: Meloidogynidae) In Hunt, D.J. and Perry, R.N. (eds) Nematology Monographs and Perspectives 14. Brill, Leiden 857p.

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