Using endophytic bacteria and arbuscular mycorrhizal fungi as alone and its combination against to angular leaf spot disease (Pseudomonas syringe pv. Lachrymans) of cucumber

The aim of this study was to investigate the effects of Endophyte bacteria (EB), Arbuscular Mycorrhizal Fungus (AMF) and their combinations on cucumber Angular Leaf Spot Disease (ALS) caused by Pseudomonas syringae pv. lachrymans (Psl), plant biomass, chlorophyll and phosphorus contents. Also, the effects of EB applications on mycorrhizal root colonization were determined by climate chamber studies. The seeds of cucumber cv. "Gordion F1" was covered with endophyte bacteria isolates Ochrobactrum sp. CB36/1, Pantoea agglomerans CC37/2, Bacillus thuringiensis CA41/1, Pseudomonas fluorescens CC44, and then, sowed in growing medium amended with AMF Glomus intraradices and Gigaspora margarita. Psl was applied by spraying to four weeks old seedlings. The disease severity of ASL was evaluated by 0-6 scale at 14th days after Psl inoculation. While the individual applications of EBs significantly reduced the severity of the disease, no effect of AMF applications was observed. The combinations of both mycorrhizal fungi species with Pseudomonas fluorescens CC44, and Glomus intraradices with Pantoea agglomerans CC37/2 were effective in suppressing disease severity. However, Pantoea agglomerans CC37/2 increased the root colonization of Gigaspora margarita. The positive effects of EB applications on plant growth were found to be higher than bout of AMF species. As a result, it has been seen that appropriate combinations of mycorrhizal fungi and endophyte bacteria can be positively contributed to plant growth and disease control.