S. Esmaili; M. Rafiei; M. Saidi; S. Beigi; Z. Tahmasebi; M. Mohammadi; M. Kohzadian
Abstract
Tomato early blight disease, caused by Alternaia solani fungus, is one of the most important diseases of tomato in the world, and also in Iran. In order to investigate the antifungal activity of some medicinal plants to control this fungus, separate experiments were conducted in a completely randomized ...
Read More
Tomato early blight disease, caused by Alternaia solani fungus, is one of the most important diseases of tomato in the world, and also in Iran. In order to investigate the antifungal activity of some medicinal plants to control this fungus, separate experiments were conducted in a completely randomized design under in vitro and greenhouse conditions. In the first experiment, the effect of concentrations of 200, 400 and 600 ppm of hydro-alcoholic extract (70% methanol and 30% water) of Thymbra spicata L., Thymus eriocalyx (Ronniger) Jalas, Satureja khuzistanica Jamzad and Oliveria decumbents Vent. with the negative (distilled water) and positive (Daconil, 3 g l-1) controls on the growth of A. solani fungus was studied under in vitro conditions. The results of the first experiment indicated complete inhibiting of fungal colony growth in all treatments. In the second experiment, 72 hours after contamination of tomato plants with A. solani fungus in an isolated greenhouse, contaminated plants were sprayed with the above-mentioned treatments and monitored for the disease symptoms 14 days later. In the third experiment, the protective effect of the above-mentioned treatments was studied. The results of the second and third experiments showed that with an increase in the extract concentration, the inhibitory and protective effects of the treatments increased. Although all treatments reduced the disease severity compared to the control, the concentrations of 600 ppm of T. spicata, 600 ppm of T. eriocalyx and 400 ppm of T. spicata, respectively had the most effective inhibitory and protective effects on the growth of fungus studied. Therefore, the use of the above treatments is recommended as a practical method for biological control of A. solani.
Y. Salahvarzi; A. Tehranifar; V. Jahanbakhsh
Abstract
In many countries, wastage of agricultural products is due to oxidative processes and microorganisms activity in warehouses. On the other hand, many plants are the sources of compounds with high antioxidant and antifungal activities that might be used as natural preservatives. To investigate the antioxidant ...
Read More
In many countries, wastage of agricultural products is due to oxidative processes and microorganisms activity in warehouses. On the other hand, many plants are the sources of compounds with high antioxidant and antifungal activities that might be used as natural preservatives. To investigate the antioxidant and antifungal properties of pomegranate, a factorial experiment based on completely randomized design with 5 replications was conducted. In this study, the effect of 3 different pomegranate parts (peel, seeds and leaf) and 2 different kind of extracts (aqueous and methanolic) with 4 concentrations (0, 500, 1000 and 1500 ppm) were investigated on 2 post-harvest fungi (Alternaria citri and Aspergillus niger). According to the results, the methanolic peel extract showed the highest inhibitory effects on the mycelia growth (IMG) and spore germination (ISG) with 47.6 and 37.7 percent respectively. Also, phenolic compounds of peel extract were 1.8 times higher than that of pomegranate leaf extract. Antioxidant capacity of peel, seeds and leaf extracts was respectively 55.3, 35.7 and 16.4%. Therefore, it seems that high antifungal and antioxidant activity of peel and seeds of pomegranate are because of high percentage of phenolic compounds in these plant parts extracts.
