the effects of combination of salicylic acid and trichoderma harzianum bi on resistance of tomato against root-knot nematode, meloidogyne javanica

abstract in this study the effect of combination of trichoderma harzianum bi and salicylic acid were studied on root knot nematode (meloidogyne javanica) disease on tomato under green house conditions. the roots of tomato seedlings at six-leaf stage were inoculated with suspensions of fungal antagonist (106 conidia/ ml), 5mm salicylic acid and 2000 second-stage juvenile (j2). combined application of salicylic acid and t. harzianum bi could decrease the severity of disease in greenhouse compared with nematode infected treatment as control. phenylalanine ammonia lyase activity and total phenolic accumulation determined on 1 to 8 days after inoculation. the using combination of salicylic acid and biocontrol agent caused increase in phenylalanine ammonia lyase activity and total phenolic compound accumulation that reached to maximum level(0.6µg/ml and 0.84µg/g respectively) 4 days after nematode inoculation. in vitro assay showed that salicylic acid and biocontrol agent(separately) increased the death percent of second stage juvenile (j2). in addition t. harzianum bi decreased the percent of egg hatching by %84 in laboratory assay. the results indicated that using of combination of salicylic acid and t. harzianum bi was able to improve root-knot nematode (m. javanica) management on tomato in greenhouse conditions.