Evaluation of the effect of allelopatic bacteria Pseudomonas fluorescens and antagonistic fungi Fusarium spp. on biological control of tomato broomrape

Broomrape (Orobanche spp.) is one of the most serious weed pathogen on many dicotyledonous plants such as tomato, cucumber, melon, tobacco and others. This weed parasite caused serious problem in tomato cultivation fields, especially in North West Iran. Some isolates of Fusarium spp. and Pseudomonas fluorescens are known as effective biological agents in biocontrol of this weed. In order to find the pathogens from broomrape, infected bromrapes were sampled from different tomato cultivation areas of Alborz province including Karaj, Hashtgerd and Nazarabad during 2011. All isolated pathogens were cultured and identified according to key references. The effect of antagonists was evaluated against tomato broomrape in greenhouse condition and the best isolates were selected for subsequent experiments. Finally, 69 isolates of the fungus including 26 isolates of F. oxysporum, 43 isolates of F. solani and then 10 bacteria contain Pseudomonas spp. were isolated. Only five isolates of Fusarium spp. including Fso84, Fso106, Fox116, Fox135, Fso145 and 3 isolates of P. fluorescens including PfN2, PfN4 and PfX8 were experienced on tomato plant in greenhouse condition. Results showed these isolates inhibited the broomrape weed growth about 65 to 73%. The combinations of fungal and bacterial Isolates including Fox104-PfX7 and Fso68-PfX showed also a good percentage of inhibition on broomrape growth.