Fatih Dadaşoğlu

Antibacterial activities of essential oils and extracts of Turkish Achillea, Satureja and Thymus species against plant pathogenic bacteria

BACKGROUND The aims of this study were to examine the chemical composition of the essential oils and hexane extracts of the aerial parts of Satureja spicigera (C. Koch) Boiss., Thymus fallax Fisch. & CA Mey, Achillea biebersteinii Afan, and Achillea millefolium L. by GC and GC-MS, and to test antibacterial efficacy of essential oils and n-hexane, chloroform, acetone and methanol extracts as an antibacterial and seed disinfectant against 25 agricultural plant pathogens. RESULTS Thymol, carvacrol, p-cymene, thymol methyl ether and gamma-terpinene were the main constituents of S. spicigera and T. fallax oils and hexane extracts. The main components of the oil of Achillea millefolium were 1,8-cineole, delta-cadinol and caryophyllene oxide, whereas the hexane extract of this species contained mainly n-hexacosane, n-tricosane and n-heneicosane. The oils and hexane extracts of S. spicigera and T. fallax exhibited potent antibacterial activity over a broad spectrum against 25 phytopathogenic bacterial strains. Carvacrol and thymol, the major constituents of S. spicigera and T. fallax oils, also showed potent antibacterial effect against the bacteria tested. The oils of Achillea species showed weak antibacterial activity. Our results also revealed that the essential oil of S. spicigera, thymol and carvacrol could be used as potential disinfection agents against seed-borne bacteria. CONCLUSION Our results demonstrate that S. spicigera, T. fallax oils, carvacrol and thymol could become potentials for controlling certain important agricultural plant pathogenic bacteria and seed disinfectant.

Influence of Summer Savory Essential Oil (Satureja hortensis) on Decay of Strawberry and Grape

Abstract The essential oil isolated from the aerial parts of wild Turkish Satureja hortensis L. (summer savory) was analyzed by GC-MS, and carvacrol (54.7 %), y-terpinene (20.9 %), p-cymene (12.3 %), a-terpinene (2.0 %), and thymol (2.0 %) were found to be major components of the oil. Post-harvest decay of fruits caused by some fungi is still a most important problem and causes major crop losses during storage and shipment. High relative humidity during storage and marketing conditions accelerate development of fungal disease and decay of the grapes. The six different concentrations of the oil (0.01, 0.02, 0.04, 0.11, 0.22 and 0.45 µL/cm3) were tested for their effectiveness in reducing decay of strawberry and grape fruits at three storage temperature (5, 10 and 20°C). The oil tested reduced decay of strawberry and grape fruits compared to controls, in particularly at low temperatures (5 and 10°C). Decay reducing effect of the oil on strawberry and grape fruits increased with increase in doses of the oil. However, microbial development in the fruits increased with increase in temperature. Nevertheless, the present results showed that S. hortensis essential oil has a significant reducing effect on the decay of strawberry and grape fruits during storage at low temperatures. Therefore, the essential oil of summer savory may be a potential source of alternative fungicides to protect strawberry and grape fruits as well as other stored products from pathogens and saprophytes.

INOCULATION EFFECTS OF PANTOEA AGGLOMERANS STRAINS ON GROWTH AND CHEMICAL COMPOSITION OF PLUM

In this study, five non-pathogenic Pantoea agglomerans strains were utilized. The objective of this study was to test for biochemical characteristics of these strains, and to evaluate their inoculation effects on fruit set rate, fruit pomological traits, fruit chemical compositions and some vegetative parameters of plum cultivar ‘Stanley’. The results showed that some of the tested strains had beneficial effects on the fruit set rate, fruit pomological traits, fruit chemical composition and/or some vegetative growth parameters of plum in comparison to the control. In conclusion, tested Pantoea agglomerans strains (especially RK-85) are the suitable inoculants for plum cultivation in cold areas such as Erzurum, and these strains may be considered as biofertilizer and protector sensitive plants against frost damage by applying in suitable timing and dose.

Effect of essential oil of Origanum rotundifolium on some plant pathogenic bacteria, seed germination and plant growth of tomato

The aim of this study is to determine effect of Origanum rotundifolium’s essential oil on some plant pathogenic bacterias, seed germination and plant growth of tomato. Xanthomonas axanopodis pv. vesicatoria strain (Xcv-761) and Clavibacter michiganensis ssp. michiganensis strain (Cmm) inoculated to tomato seed. The seeds were tested for germination in vitro and disease severity and some plant growth parameters in vivo. In vitro assay, maximum seed germination was observed at 62,5 µl/ml essential oil treatment in seeds inoculated with Xcv-761 and at 62,5 µl/ml essential oil and streptomycin treatment in seeds inoculated with Cmm. The least infected cotiledon number was observed at 500 µg/ml streptomycin treatment in seeds inoculated with Cmm. In vivo assay, maximum seed germination was observed at 250 µl/ml essential oil teratment in tomato inoculated with Cmm. Lowest disease severity, is seen in the CMM infected seeds with 250 µl/ml essential oil application these results were statistically significant wh...

Identification and characterisation of potential biofertilizer bacterial strains

In this study we aimed that isolation, identification and characterizations of PGPR strains from rhizosphere of legume plants. 188 bacterial strains isolated from different legume plants like clover, sainfoin and vetch in Erzurum province of Turkey. These three plants are cultivated commonly in the Erzurum province. It was screen that 50 out of 188 strains can fix nitrogen and solubilize phosphate. These strains were identified via MIS (Microbial identification system). According to MIS identification results, 40 out of 50 strains were identified as Bacillus, 5 as Pseudomonas, 3 as Paenibacillus, 1 as Acinetobacter, 1 as Brevibacterium. According to classical test results, while the catalase test result of all isolates are positive, oxidase, KOH and starch hydrolysis rest results are variable.