evaluation of resistance caused by arbuscular mycorrhizal fungi against root knot nematode (meloidogyne javanica) in tomato (lycopersicon esculentum mill.).

in this research the effect of two species of arbuscular mycorrhizal fungi, glomus mosseae and glomus intraradices on root knot nematode, meloidogyne javanica was investigated and in different treatments the effects of this interaction on parameters of plant growth , nematode infection and mycorrhizal development were evaluated.shoot fresh and dry weight significantly increased in mycorrhizal treatments and root fresh and dry weight increased significantly in nematode treatments . these changes may be related to plant growth promotion and induction of resistance against nematode by amf and also increase of root weight because of gall induction by nematode infection.the parameters of nematode disease including number of galls and eggsacs significantly reduced in mycorrhizal treatments compared to nematode treatments that shows reduction of attack and inhibition of nematode propagation . in mycorrhizal frequency there is not significant difference between treatments that confirms root knot nematode has not inhibitory effect on mycorrhizal development . in mycorrhizal density we have significant difference between treatments of two amf, that shows g.mosseae has a higher colonization ability and this demonstrate that lower ability of g.intraradices in control of nematode infection parameters may be related to low colonization percentage . totally this experiment shows that we can use amf as a biological control agent to control of root knot nematode and promotion of plant growth.