فهرست مطالب مهین صابری

One of the methods of plant disease control especially in organic farming is the use of natural ingredients. In this study, the inhibitory effects of volatile and non-volatile metabolites of wood vinegar (Pyrolignious acid) on the mycelial growth of Phytophthora drechsleri and Pythium aphanidermatum and on the growth traits of the greenhouse cucumber were studied in vitro and in situ conditions. To study the effect of non-volatile metabolites, mycelial disks were placed on PDA culture medium containing 0, 0.025%, 0.05%, 0.125%, 0.25%, 0.37%, 0.5% and 0.75% of wood vinegar. To study the effectual volatile metabolites mycelia disks placed on one side of walled-petridishes, while on the other side, the above-mentioned concentrations were added. Both volatile and non-volatile metabolites inhibited significantly (at 0.05 probability level) the fungal growth P. aphanidermatum and P. drechsleri in vitro conditions. In greenhouse conditions, cucumber seedlings were transplanted into pot soil inoculated with fungus. Three concentrations of wood vinegar showed the maximum inhibitory effect on mycelial growth. Disease severity was significantly reduced in all concentrations used (α= 0.05). All concentrations of wood vinegar significantly increased the weight, length and height of the plants compared to the control (α= 0.05).

Verticillium wilt caused by Verticillium dahliae is an important disease of cucumber grown in greenhouses. In this study, the inhibitory effects of volatile and non-volatile metabolites of wood vinegar (Pyrolignious acid) on the mycelial growth of V..dahliae as well as the combined effects of wood vinegar and vermicompost on the control of associated disease were studied in vitro and in situ conditions. To study the effect of non-volatile and volatile metabolites, 0, 0.025%, 0.05%, 0.125%, 0.25%, 0.37%, 0.5% and 0.75% of wood vinegar were tested. Four replicates were considered for each concentration. The mycelial growth of the fungus was measured daily up to 10 days. Bothvolatile and non-volatile metabolites inhibited significantly the fungal growth in vitro conditions at 0.05 probability level. Three concentrations of wood vinegar 0.125%, 0.25%, 0.5% were drenched into the soil one and 14 days post- transplanting. The effect of treatments was assessed through measurement of disease severity index, wet and dry weight of roots and shoots, as well as root length and shoot height. Disease severity was significantly reduced in all concentrations used (α= 0.05). The combination of vermicompost and vinegar reduced the pathogenicity of the pathogen and increased the weight of roots and shoots.

Root rot and vine decline disease caused by Monosporascus cannonballus and charcoal root rot disease caused by Macrophomina phaseolina are important diseases of melon plants in Iran. In this study, the efficacy of wood vinegar on the mycelial growth of these pathogens as well as the integrated effect of wood vinegar and compost tea were examined on the control of root rot and vine decline disease. To test the antifungal activity of wood vinegar, mycelial disks (3 mm in diameter) of M. cannonballus and M. phaseolina were placed on PDA culture media amended with different concentrations of wood vinegar (0.025, 0.05, 0.37, 0.5, 0.75 v/v). Wood vinegar inhibited the mycelial growth of both pathogens at 0.05 probability level. In green house condition, muskmelon seeds were sown into pot-soil containing 15% v/v of compost tea and infested with M. cannonballus. Three concentrations of wood vinegar (0.125%, 0.25%, 0.5%) which had shown the maximum inhibitory effect on mycelial growth in the laboratory were then drenched into the soil. Results showed that disease severity was significantly reduced in all concentrations used (α= 0.05). The integration of compost tea and wood vinegar reduced the pathogenicity of M. cannonballus up to 94% compared with untreated control. Roots and shoots weights increased by 8% and 25% respectively in the presence of wood vinegar and compost tea (α= 0.05).

Retina is a part of the central nervous system derived from the neuroectoderm and made up of 5 layers. In this study، the changes in the thickness of the retinal layers as a consequence of diabetes and effect of Aloe Vera gel extract in male rats were assessed. Thirty Sprague Dawley adult male rats (175 ± 25 g) in two age groups (4 and 8 weeks) were divided into 6 groups of 5 as control، diabetic and diabetic receiving 400 mg/kg Aloe Vera extract. Diabetes was induced by IP injection of 50 mg/kg of STZ (streptozotocin). The animals were weighed and their blood sugar was measured by glucometer before STZ administration and 24 h thereafter. Animals were anesthetized with sodium thiopental (40 mg/kg) via IP injection. After removal of eyes on both sides، retina was dissected out precisely and fixed in 4% glutaraldehyde، post fixed in osmium tetroxid 1%، dehydrated and then embedded in TAAB resin. Thin sections (1 μm) were stained with toluidine blue stain and viewed under light microscope. Ten slides were prepared from each animal. The results revealed reduction of the blood glucose levels and body weight in treated rats in comparison to diabetic groups. The thickness of neural retina and its layers were different as well. In the group treated with Aloe Vera the thickness of retina and its layers retained their normal histologic structures.