In this study, antibacterial effects of semi-parasitic plant common mistletoe (Viscum album L.), collected from different woody host, extracts on the tomato bacterial cancer and wilt disease agent Clavibacter michiganensis subsp. michiganensis, pepper and tomato bacterial leaf spot disease agent Xanthomonas axonopodis pv. vesicatoria and tomato bacterial leaf spot disease agent Pseudomonas syringae pv.tomato were determined. The common mistletoe collected from pine, pear, acacia and mahaleb trees. The leaves and stems water extracts of common mistletoe were added to Nutrinet agar medium before autoclaving at the final concentrations of 1%, 2.5%, 5% and 10%. The bacterial concentration was adjusted to 108 cfu/ml with spectrophotometer to within an 0.2 at 600 nm. Then, 100 µl of bacterial inoculums were spread over the extracts amended media plates. As a control group, pathogens were plated on the unamended media. The study was established in 3 repetitions and repeated 2 times. At the end of the incubation period, bacteria growing on all treated petri dishes were collected and their density was measured in a spectrophotometer. Based on the results of the study, 1% and 2.5% concentration of the extracts obtained from leaves and stems of common mistletoe collected from different trees were not effective on the bacteria tested, while 5% and 10% concentration of them inhibited the bacterial growth completely (100%). Also, it was observed that there wasn’t difference on the pathogens on the basis of the host where mistletoe was collected. According to the results of this study conducted under in vitro conditions, in vivo studies should be carried out with the common mistletoe extract, which is effective on the bacterial pathogens.
Biological control of tomato leaf spot disease caused by Alternaria alternata using Chaetomium globosum and some other saprophytic fungi
