Investigation of allium tuncelianum extracts against some important pathogens in tomato and pepper

In this thesis, determination of in vitro and in vivo effects of etanol extract of Allium tuncelianum on nine important pathogens of tomato and pepper and total phenolic compounds in plants were studied. In vitro tests conducted for the direct effects and volatile components effects of extract, the 0-1.5% doses of direct effect and full dose with cover culture on mycelial development of fungal and fungal like agents and colony development of bacterial agents were determined. The mycelial development of Pythium deliense and Rhizoctonia solani were completely inhibited by 1.5% dose of extract while the mycelial development of Fusarium oxysporum f.sp. lycopersici was decreased by 51.3%. Volatile compounds of extract decreased the colony development of F. oxysporum f.sp. lycopersici and Sclerotium rolfsii by 67.7% and 55.7%. The colony development of Pseudomonas syringae pv. tomato and Clavibacter michiganensis subsp. michiganensis were inhibited by 100% and %42, respectively, with 1.5% dose of the extractand volatile compounds was inhibited by 63.6% and 62.2%, respectively with full dose of extract.In pot conditions, 0.5%, 1.0% and 1.5% doses of the extract were applied to plant as soil irrigation against soil-borne pathogens and as spraying against bacterial speck of tomato and disease severity was determined after pathogen inoculation at the end of the experiment. According to the results of the pot study, the disease severity of fungal and fungal-like agents including Botrytis cinerea, F. oxysporum f.sp. lycopersici, P. deliense, R. solani and S. rolfsii were decreased with increasing doses and reduction ratios were determined as 76.8%, 56.6%, 47.4%, 85.8% and 53.1%, respectively at 1.5% dose of the extract. In the experiment, the total amount of phenolic compounds in the treatments immediately after the assessment of disease was determined by the spectrophotometric method. Total amount of phenolic compounds in tomato and pepper plants increased at a certain level in response to the in pathogen applied alone compared to control, but amount was determined to be much higher compared to the control in different doses of extract and pathogen combinations.As a result of the study, the ethanol extract of garlic were effective in vitro and in vivo reducing the development of some pathogens and promising results were obtained.