فهرست مطالب عبدالناصر محمدی غلامی

Salinity stress is one of the environmental factors limiting plant growth and development and has negative effects on morphological and physiological parameters of plants. Therefore, various compounds have been used to reduce the harmful effects of this stress. According to previous studies, metal nanoparticles have both negative and positive effects on different plant species. The aim of this study was to investigate interaction effects of different concentrations of ZnO nanoparticle and NaCl on morphological parameters, photosynthetic pigments and protein content in Ardestanian and mashhadian cultivar of Fenugreek. Factorial experiment was performed in a completely randomized design with three replications and three levels of ZnO nanoparticle (0, 1000 and 3000 ppm) and four levels of NaCl (0, 75, 150 and 225 mM) were used. The results showed that salinity stress significantly decreased shoot and root fresh weight, as well as the percentage of relative water content root at 225 mM NaCl in both cultivars. The highest fresh weight of shoot in Mashhadian cultivar was observed in the interaction of 75 mM NaCl and 1000 ppm of ZnO nanoparticle. In general, ZnO nanoparticles improved fresh and dry weight in both cultivars. In Ardestanian cultivar, the highest amount of phenol was observed in the concentration of 3000 ppm of nanoparticle and 225 mM NaCl, also the highest flavonoid content was observed in the interaction of 3000 ppm of nanoparticle and 150 mM NaCl. The highest photosynthetic pigments were observed at interaction of 75 mM NaCl and 3000 ppm of nanoparticle in two cultivars. Increasing the concentration of nanoparticle also led to a significant increase in carotenoids in both cultivars. The most antioxidant activity based on IC50 was in Mashhadian cultivar and in the interaction of 225 mM NaCl and 3000 ppm of nanoparticle. The results of this study showed that the application of ZnO nanoparticle under salt stress caused the growth of the plant to improve.

Thyme daenensis, scientifically known as Thymus daenensis Celak belongs to the Lamiaceae family. The aerial part of Thymus daenensis encompasses phenolic compounds and has powerful antifungal and antioxidant properties. Due to its potential to produce the secondary metabolites, it also has anti-mutation and anti-cancer properties. In this study, in order to investigate the phytochemicals, antioxidant, antifungal properties and also the cell cytotoxicity, the aerial parts of Thymus daenensis were collected from Zagheh area in Lorestan province Khorramabad, in June 2017. The chemical compounds of the essential oil were extracted using water distillation and analyzed using Chromatography (GC) and Gass Chromatography-Mass Spectrometry (GC/MS). Broth microdilution, MTT, and DPPH methods were utilized to determine the antifungal and antioxidant properties and cell cytotoxicity, respectively. In the essential oil, the most significant compounds were thymol (24.7%) and carvacrol (38.5%) and the Minimum inhibitory concentration against Aspergillus fumigatus and Aspergillus niger were respectively 0.5 and 1 μg/ml. The radical inhibitory effect increased as the density of the essential oil increased (IC50=63/23). The MTT assay indicated that the impact of the essential oil cytotoxicity on human lymphocyte cells was insignificant. According to the results obtained, it can be concluded that the essential oil of Thymus daenensis, as one of Iran’s indigenous plants, has considerable antioxidant properties that have potential to be used in pharmaceutical industrieTs and act as a good candidate in the fungal diseases’ treatment.

Fusarium species are prevalent contaminants of foodstuffs and agricultural crops. They produce fumonisins، which are carcinogenic mycotoxins. The present study has evaluated maize and wheat samples from ten provinces in Iran that were contaminated with Fusarium species. Special attention was paid to the ability of the isolates to produce fumonisin B1 (FB1) as a public health hazard. We collected 32 maize and 15 wheat samples from ten provinces that were major cultivation areas. Samples surface disinfected with a 1% sodium hypochlorite solution for 2 minutes. Fusarium species were isolated by the flotation method on malachite green agar. Pure cultures on potato dextrose agar (PDA) were identified using a combination of macroscopic and microscopic morphological criteria. The ability of the isolates to produce FB1 was evaluated by thin layer chromatography (TLC) and the amounts of fumonisin B1 produced were assessed by high performance liquid chromatography (HPLC). A total of 55 Fusarium isolates that belonged to five species were isolated. There were 27 of the 32 maize samples (84. 4%) and 11 of 15 wheat samples (73. 3%) that were contaminated with Fusarium species. Species consisted of F. verticillioides (23 isolates)، F. proliferatum (22 isolates)، F. subglutinans (5 isolates)، F. nygamai (4 isolates) and F. redolens (1 isolate) based on morphological criteria. Twenty-two of the 55 (40%) Fusarium isolates produced FB1 in a total range from 230. 4 to 9565 µg/ml. The highest amounts of FB1 production were related to toxigenic isolates of F. verticillioides and F. proliferatum. Results of the present work indicates a high degree of contamination of maize and wheat with Fusarium strains that belong to the Gibberella fujikuroi species complex وparticularly F. verticillioides and F. proliferatum. This contamination is a potential public health threat due to food spoilage and subsequent production of high levels of carcinogenic FB1.