Determination of biological activity of some bacteria species against Sclerotinia sclerotiorum

In this study, it was aimed to determine the biological activities of 6 bacterial strains (Bacillus sp., Paenibacillus polymyxa, B. thrungiensis, B. anthracis, B. amyloliquefaciens, Pseudomonas alcaligenes) isolated from agricultural areas of Kırşehir province, under in vitro (on PDA and TSA medium) and in vivo (on cucumber fruit) conditions, against the plant pathogen Sclerotinia sclerotiorum that causes white rot disease in cucumbers. For this purpose in vitro conditions; three different methods were used: the effect of bacterial species on the mycelium development of the fungus, the effect of the fungus on the sclerot structures and the effect of the volatile compounds of the bacterial species on the fungus. In the applied petri dishes, conditions of prevention the development of bacterial species on S. sclerotiorum were observed. As a result of in vitro studies, the method in which the effect of the fungus on the sclerot structures was investigated, was determined as the method that gave the most effective results on the fungus. As a result of this method, Bacillus sp. SWU8-1, Paenibacillus polymyxa RS-10 and B. amyloliquefaciens B11 strains were determined as the most effective bacterial strains against S. sclerotiorum with 100% inhibition rates. In vivo activity studies, the contact effect of bacterial species and the steam effect of volatile compounds of bacterial species against S. sclerotiorum were determined on cucumber fruit. As result of the study, the method in which the contact effect of bacterial strains against S. sclerotiorum was investigated, was determined as the most effective method under in vivo conditions. By this method, it was determined that 3 bacterial strains (Bacillus sp. SWU8-1, Paenibacillus polymyxa RS-10 ve B. anthracis X19) prevented the development of fungi on the plant by 100%. It is believed that the high effectiveness of this method is due to the fact that bacteria are focused on contact with the plant.