Phytotoxicity of coumarin on two weed species Trifolium and Medicago sativa and two plant pathogenic fungi Sclerotinia sclerotiorum and Aspergillus fumigatus

Abstract

• Coumarins are a group of secondary metabolites of plants from the phenylpropanoids category, many reports of the biological activity of these compounds have been published, these compounds are found in the legume family (Fabaceae), the sedab family (Rutaceae) and the umbrella family (Apiaceae). Phytotoxic effects of simple coumarin on Trifolium and alfalfa seeds and also the inhibitory effects of coumarin on plant pathogenic fungi such as Sclerotinia sclerotiorum and Aspergillus fumigatus were studied. Physiological parameters evaluated include root and shoot growth of these seeds as well as fungi growth. First, the mentioned compound was dissolved and different concentrations including 0.001, 0.01, 0.1 and 1 mg/ml were prepared by diluting it in distilled water Also, for fungis, different concentrations of coumarin including 0.25, 0.5 and 1mg/ml were prepared in the culture medium, and a sample containing distilled water was considered as a control, which was done in three repetitions. The petri dishes containing seeds and culture media containing fungi were placed separately in an incubator with a temperature of 25 degrees Celsius.
• The results showed that coumarin in all the treated concentrations, i.e. 0.001 mg/ml and above, had a negative effect on the germination, growth of the root and shoot of these seeds Also, in all the treated concentrations of the fungi culture medium, i.e. 0.25 mg/ml and above, it had a negative effect on the growth of fungus. At a concentration of 1 mg/ml, it completely prevents the germination of trifolium and alfalfa seeds and also from the growth of fungus. The final goal of this study is to find natural herbicides to replace them with artificial ones that have harmful effects on the environment.