Enhanced Biological Control of Phytophthora Blight of Pepper by Biosurfactant-Producing Pseudomonas

Abstract

Pseudomonas isolates from different crop plants were screened for in vitro growth inhibition of Phytophthora capsici and production of biosurfactant. Two in vivo experiments were performed to determine the efficacy of selected Pseudomonas strains against Phytophthora blight of pepper by comparing two fungicide treatments [acibenzolar-S-methyl (ASM) and ASM + mefenoxam]. Bacterial isolates were applied by soil drenching (1 × 109 cells/ml), ASM (0.1 μg a.i./ml) and ASM + mefenoxam (0.2 mg product/ml) were applied by foliar spraying, and P. capsici inoculum was incorporated into the pot soil three days after treatments. In the first experiment, four Pseudomonas strains resulted in significant reduction from 48.4 to 61.3% in Phytophthora blight severity. In the second experiment, bacterial treatments combining with olive oil (5 mL per plant) significantly enhanced biological control activity, resulting in a reduction of disease level ranging from 56.8 to 81.1%. ASM + mefenoxam was the most effective treatment while ASM alone was less effective in both bioassays. These results indicate that our Pseudomonas fluorescens strains (6L10, 6ba6 and 3ss9) that have biosurfactant-producing abilities are effective against P. capsici on pepper, and enhanced disease suppression could be achieved when they were used in combination with olive oil.

Identification of endophytic Bacillus mojavensis with highly specialized broad spectrum antibacterial activity

“…B. mojavensis isolated from diverse environments have been reported to have significant activity against phytopathogens also (Özyilmaz and Benlioglu 2013). But B. mojavensis BmB 4 isolated in the study was not found to have any activity against phytopathogens when it was tested and it might have specialised for broad antibacterial activity as part of its endophytic adaptation.…”

Isolation and characterization of Bacillus altitudinis JSCX-1 as a new potential biocontrol agent against Phytophthora sojae in soybean [Glycine max (L.) Merr.]

“…Different lowercase letters above the bars indicate significant difference between the treatments at P < 0.05 level by ttest Many studies reported that the application of Bacillus spp., such as B. subtilis, B. cereus, Bacillus licheniformis, could manage diseases caused by Phytophthora species, such as Phytophthora capsici, P. sojae, Phytophthora fragariae var. fragariae, Phytophthora infestans, and Phytophthora cactorum on pepper, soybean, potato, cucumber, alfalfa, strawberry and apple (Utkhede 1984;Handelsman et al 1990;Osburn et al 1995;Anandhakumar and Zeller 2008;Özyilmaz and Benlioglu 2013;Maksimov et al 2014;Khabbaz et al 2015).…”

Application of PGPR and Antagonist Fungi-based Biofungicide for White Rust Disease Control and Its Economyc Analysis in Chrysanthemum Production

“…tritici on wheat (Thomashow and Weller 1988), Ralstonia solanacearum on tomato (Barret et al, 2009), stem rot disease caused by Phytium spp on cotton (Erdoğan, Bölek, & Göre, 2016). The combination of Pf and B. subtilis was able to reduce Plasmodiophora brassicae on chinese cabbage (Zhao et al, 2016) and Phytopthora capsici in pepper (Özyilmaz & Benlioglu, 2013). (Table 2 and Table 3) reflected to the more plants having qualified physical appearance.…”