The combined effect of root-knot nematode and broomrape on tomatoes chlorophyll content, fluorescence parameters and relative water content under greenhouse conditions

Different species of the root knot nematodes (Meloidogyne spp.) and broomrape Orobanche aegyptica are parasitic of different plants roots. In order to study the interaction between the parasites of tomato, an experiment was conducted in a completely randomized design with four treatments 1- control, 2- nematode (2000, second stage juveniles), 3- seeds of orobanche (30 mg per kg of soil) and 4- nematode (2000, second stage juveniles), with seeds of orobanche (30 mg per kg of soil) with four replications under greenhouse conditions. Treated seeds were planted in sterilized soil. Four-leaf stage seedlings were inoculated with treatments and transferred to pots and fluorescence parameters were measured after 60 days. The results showed that both biological stresses caused a significant reduction in shoot dry weight, number of galls, chlorophyll, leaf number, leaf area, plant height, root length, stem diameter and photosystem II quantum efficiency in both light and darkness compared with control. Also the number of second stage larvae, egg sacs, accessories orobanche, nematode reproductive factor, the M, F, QP, QN, NPQ, Fo, Fm and Fv of both light and darkness in the combined treatment were increased. Whereas the dry weight of root in nematodes tension increased and were decreased in stress of aegyptian orobanche. The root volume was highest in alone nematode treatment. The results indicated that root- knot nematode and orobanche had a synergistic effect.