Antibacterial potential of five lichen species from Arasbaran region against Dikerya chrysanthemi potatoes rot causal agent in the laboratory and storage condition

Potato is one of the important vegetables which is tremendously getting damaged by Dikerya chrysanthemi causing soft rot during storage. In order to utilize lichens antibacterial potential to the disease management, five lichen species collected from Arasbaran region including Pleopsidium gobiensis, Ramalina sinensis, Parmelina tiliacea, Anaptychia setifera and Lecanora argopholis were extracted using ethanol, acetone and diethyl ether as solvents and bioassayed in laboratory condition by disc diffusion, minimal inhibitory and bactericidal concentration (MIC and MBC) methods. Pleopsidium gobiensis methanolic extract and Parmelina tiliace diethyletherextract were the most effective treatments against the bacterium with 7.9 and 6.6 mm of inhibition zone and 0.54 and 1.09 mg/ml of MIC and MBC, respectively. They were even more effective than Streptomycin which were used as positive controls. On the whole, P. tiliacea and P. gobiensis had the highest inhibitory effects on bacterial growth. In storage condition, spraying injured potato tubers with bacterial suspensionbefore or after selected lichens separate inoculations showed that all lichen treatments had protective and curative potential effects on bacteria, being able to save significant part of potato tubers from bacterial damage in comparison to the control. The most effective treatment was diethyl ether extract of R. sinensis applied after bacterial inoculation which could protect 91% of potato tubers from bacterial damage.