gholam reza valizadeh

Toxoplasma gondii is one of the most common parasites worldwide. It is of great importance to identify new potential drugs that are effective and less harmful in pregnant women and newborns. We investigated nanoemulsion miltefosine (NEM) in treating experimental acute and chronic toxoplasmosis.

A combination of triacetin, Tween 80, and ethanol (1:2) was used for the development of NEM formulations. The size of NEM was calculated to be 17.463 nm by DLS and TEM. To investigate the performance of miltefosine (MLF), NEM, sulfadiazine (SDZ), and pyrimethamine (PYR) (positive control) in vivo, acute toxoplasmosis was induced in mice by an intraperitoneal injection of RH strain tachyzoites. After five days, the mice were examined for the number and condition of tachyzoites and histopathological changes in the liver and spleen. Chronic toxoplasmosis was investigated in rats and the number and size of brain cysts along with histopathological changes were assessed in different groups.

The results of the in vivo assessment of drugs in acute toxoplasmosis showed the following order regarding a decrease in the number of tachyzoites and an increase in survival rate: SDZ&PYR > NEM > MLF. The effects of drugs on chronic toxoplasmosis showed a significant effect of NEM (50%) on reducing the number of cysts compared to SDZ&PYR (10%) and MLF (12%) and reducing the size of NEM brain cysts (21%) compared to SDZ&PYR (5 %) and MLF (8%).

Increasing the penetration of NEM through the blood-brain barrier (BBB) and subsequently reducing the number and size of T. gondii tissue cysts is a promising new drug in treating chronic toxoplasmosis.

To evaluate rainfall productivity and grain yield of dryland wheat genotypes under different rotation and tillage managements, a split-split plot experiment based on RCBD with three replications was conducted in Dryland Agricultural Research Institute for 4 years (2016-20). Three crop rotations (chickpea-wheat, safflower-wheat, and vetch-wheat) were located in main plots and three different tillage methods (conventional, minimum, and zero tillage) were considered in subplots and two Baran and Azar 2 wheat genotypes were considered in sub-sub plots. Results indicated tillage and crop rotation treatments significantly affect precipitation efficiency. Maximum rainfall productivity was recorded for Baran in zero and minimum tillage systems with forage (vetch) rotation by 0.71 and 0.7 kg/m3. Rainfall productivity under zero tillage treatment during three years of the experiments increased from 0.45 up to 0.67 (approximately 32 %). The highest relative water content, stomatal conductance and harvest index were recorded from Baran in vetch rotation under zero tillage treatment. The highest grain yield was belonged to the vetch, chickpea and safflower rotations by 2231, 2105 and 1991 kg/ha, respectively. With increasing soil water content and improving rainfall productivity in the conservation agriculture system, grain yield was increased by 5% and 8 % under minimum and zero tillage treatments than that of a conventional system. Therefore, in cold rainfed climates, in order to develop in wheat conservation, it is recommended to the application of autumn forage and chickpeas rotation in zero tillage conditions.

To investigate the effect of different amounts of Hungarian vetch residues on growth and yield of wheat cultivars in cold regions, an experiment was conducted in a strip plot design based on randomized complete block design with three replications during the growing years of 2014-2017 at Dryland Research Institute of Iran, Maragheh Station. The amounts of vetch residues in three levels of 0, 1.5 and 3 ton/ha as horizontal factor and wheat cultivars including Homa, Azar2 and Baran as vertical factor were evaluated. The experiment was carried out on forage – wheat rotation farm, and the plant residues of the vetch were added to the experimental plots spread uniformly on the surface of the soil. Plant residues of 1.5 tons per hectare had a positive effect on early establishment of seedlings in the field, yield and yield components of wheat. Homa cultivar had the highest positive reaction to the addition of green vetch residues in the amount of 1.5 tons per hectare in terms of thousand kernel weight, grain yield, biomass yield, harvest index, productivity rate and recipitation efficiency index. Therefore, the maintenance of vetch residues of 1.5 tons per hectare can improve the yield of wheat.

To evaluate the effects of primitive seed phosphorus content through different phosphorus use on parent plants on growth traits and grain yield of three barley cultivars; a research was conducted as factorial experiment based on randomized complete block design with three replications during 2012- 2013 at Dryland Agricultural Research Institute (DARI), Maragheh station, Iran. Factors were cultivars including Sahand, Abidar and Dayton and primitive seed phosphorous contents that applied in previous year on parent plants at 0, 15, 30 and 45 kg.ha-1 rates. Seed phosphorus percentage was measured in parent plants in different seasons and results showed significant difference in seed phosphorus content through different phosphorus fertilizers application in parent plants and using of 30 and 45 kg.ha-1 of phosphorus fertilizer was more effective than other treatments. Sahand × 30 kg.ha-1 combination was a superior treatment in seed phosphorus content, grain yield, productivity degree, harvest index and green cover percentage but biological yield and can be recommended in fall cultivation of rainfed barley in this and other climatically similar regions.

ABSTRACT Low germination and wheat seedling emergence problems are the most important difficulties under rainfed condition.Better and enough application of nitrogen in parent plants nutrition can play important role in production of seeds with high quality and vigor. The current research was conducted to evaluation the effects of different nitrogen rates in wheat cv. Azar2 parent plants on germination, seed vigor and seedling establishment. Laboratory tests were conducted as completely randomized design with five treatments including nitrogen fertilizer 0, 30, 60, 90 and 120 kg/ha in four replications and field experiment was carried out as randomized complete block design in three replications in 2013- 2014 growing season at Dryland Agricultural Research Institute (DARI) in Iran. All traits including viable seed percentage, electrical conductivity, germination rate and root, shoot and seedling dry weight, but viable seeds were significantly affected by different nitrogen fertilizer rates in wheat parent plants. Seedling emergence rate and seedling emergence percentage affected significantly by different nitrogen fertilizer rates in parent plants at 1 and %5 levels, respectively. Seedling emergence percentage and rate in 60, 90 and 120 kg/ha, were located at the same group. Therefore, application of 60 kg/ha nitrogen fertilizer in parent plants of wheat cv. Azar2 are recommended for production of vigorous seed and seedling establishment in the field.

Changes of soil physico-chemical properties for different management systems leading to change phosphorusrequirement، adsorption and buffering capacity in soils were studied. Soil samples of different soil management systems were analyzed for soil properties changes. Then، phosphate adsorption isotherms for the soils of different managements ((Langmuir adsorption isotherm) were examined. For all samples، adsorption of P was determined at standard equilibrium concentration (C). Adsorption capacity (Xm)، requirement and buffering capacity were determined from plot of C/X as function of C with linearly equation (C/X= C/Xm+1/K*Xm). The results indicated that different soil management systems changed soil physico-chemical properties. P sorption curve showed that with an increase in equilibrium concentration of P، the amount of adsorbed P increased linearly at different soil management systems. Accordingly، by using Langmuir adsorption isotherm، results indicated that phosphorus adsorption capacity differed from 800 to 1500 mg/kg at different soil managements. P adsorption capacity in natural pasture and forage-wheat system compared to others systems were highest. The lowest P adsorption capacity was at fallow-wheat system. It can be concluded that soil management systems change soil physico-chemical properties. P requirement، adsorption and buffering capacity were varied for different soil management systems. Phosphorus availability depend on P adsorption and buffering capacity.