Phytoparasitic nematodes

Lambert, K.N., Allen, K.D. and Sussex, I.M. (1999) Cloning and characterization of an esophageal-gland-specific chorismate mutase from the phytoparasitic nematode Meloidogyne javanica. Molecular Plant-Microbe Interactions 12, 328-336. 

Chellemi DO, Olson SM, Scott JW, Mitchell DJ, McSorley R (1993) Reduction of phytoparasitic nematodes on tomato by soil solarization and genotype. J Nematol 25(4S) 800-805... 

Kluepfel DA, Nyczepir AP, Lawrence JE, Wechter WP, Leverentz B (2002) Biological control of the phytoparasitic nematode Mesocriconema xenoplax on peach trees. J Nematol 34 120-123 Kodama T, Fukui T (1982) Solar heating in closed plastic house for control of soil borne diseases. Application for control of Fusarium wilt of strawberry. Ann Phytopathol Soc Japan... 

O Day MK, Niblack TL, Bailey WC. Phytoparasitic nematode populations in Festuca arundinacea field plots in southwestern Missouri. J Nematol 25 900-906, 1993. 

Allelochemicals may also be released into the environment as a defence against phytoparasitic nematodes [173]. Juvenile hormones have been shown to affect the development of nematodes [174]. Juvenile hormone I and MF inhibited hatching of the eggs of Haemonchus contortus [175] and application of JH III (3.4 mM) to third-stage larval females of the rodent hookworm, Nippostrongylus brasiliensis, resulted in a 50% reduction in egg production [176]. The biosynthetic precursor of JH III, famesol, inhibits development of larvae of the nematode Trichinella spiralis [177]. However, in the few studies done, these compounds do not appear to have an effect on plant parasitic nematodes [175, 178]. 

The first monoterpene found to have anthelmintic activity was ascaridole (6) which, alone or as a component of plant extracts, has been used in the treatment of hookworm infection [37]. Ascaridole is also a potent in vitro inhibitor (LC 0.05 jiM) of the development of the malarial parasite Plasmodium falciparum [173]. Thymol also exhibits anthelmintic activity, but is too toxic to be considered for use in animals and humans [37]. Since many monoterpenes taken internally in high doses are known to cause problems (irritation, acute toxicity) [174], more attention has been paid to evaluating these compounds against phytoparasitic nematodes. 

Extracts and exudates of neem trees, Azadirachta indica (Meliaceae), have biological activity against a variety of different nematodes. For example, a neem seed extract applied to tomato plants as a root drench at 125 fxg/ml inhibited reproduction of the root-rot nematode Meloidogyne javanica (Chitwood, 1992). Azadirachtin (33), at 10 xg/ml, inhibits microfilarial release in the animal-parasitic nematode, Brugia pahangi. A similar mode of action may be involved in phytoparasitic nematodes (Chitwood, 1992). 

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