مقالات رزومه محدثه شمس الدین سعید

Nowadayes, due to the increasing use of phosphorus fertilizers in agricultural lands, the salinity of the soil along with contamination with heavy elements such as cadmium has increased sharply. Plants' response to a particular stress is different from when they experience multiple stresses simultaneously. The aim of this experiment was to investigate the simultaneous effect of salinity and cadmium stresses on morphological and physiological characteristics of Kochia.

For this purpose, a factorial greenhouse experiment based on a randomized complete block design with four replications was conducted in the educational-research greenhouse of the Faculty of Agriculture, Valiasr University of Rafsanjan in 1397. Experimental factors included four different levels of salinity stress (0, 6, 12 and 18 dS/m) and cadmium concentration in soil (0, 1, 5 and 10 mg/kg soil). The studied traits included dry weight of branches, stems and leaves, RWC, concentration of chlorophyll a, b and a + b, enzymes activity of superoxide dismutase, peroxidase, catalase, the concentration of cadmium, iron, zinc, manganese, calcium and magnesium.

The results showed that due to increasing salinity to 18 dS/m the dry weight of branches, leaf and stem dry weight and leaf area, RWC, concentration of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids decreased by 56.8, 48.01, 50, 46.09, 21, 53.76, 56.91, 53.75 and 51.21 percent, respectively. By increasing the cadmium concentration to 10 mg/L, the dry weight of lateral branches, leaves, stems and leaf area decreased by 24.32, 31.89, 28.45 and 41.24%, respectively, but the concentration of leaf cadmium compared to the control treatment1.7 times was increased. The activity of superoxide dismutase, peroxidase and catalase enzymes in treatment of 18 dS/m salinity alongside with 10 mg/L cadmium were 1.83, 1.4 and 4.7 times higher than the control treatment, respectively. Leaf iron, zinc, calcium and magnesium concentrations decreased by 73.07%, 51.51, 51.8%, 0.17 and 0.26% with increasing salinity stress to 18 dS/m, respectively, and with increasing cadmium concentration to 10 mg/L increased iron concentration by 37.32% and zinc and magnesium concentrations decreased by 28.70 and 0.12%, respectively.

The highest dry matter of Koshia in salinity and cadmium stress treatments belonged to the control treatment and the lowest dry matter were obtained from 18 dS / m salinity and 10 mg / kg cadmium in soil.

Biochar is a carbonaceous substance obtained from heating plant residues and wastes in an oxygen-containing medium with or without oxygen. Thermal decomposition of biomass in an oxygen-free medium is called thermophilicity (pyrolysis). Temperature is one of the factors influencing the characteristics of biochar. One of the objectives of this experiment is to investigate the effect of different temperatures on the biochar characteristics of cattle manure. The use of biochar as a soil conditioner and source of organic carbon in agricultural soils with minimal environmental damage is considered. Marigold is an annual plant that is used in industry and pharmacy in addition to food. Another aim of this experiment is to investigate the effect of biochar use from different temperatures on marigold under salinity stress.

For biochar preparation, after collecting cattle manure from Bardsir farms, air drying and sieving were used for pyrolysis process for four hours at different temperatures (300, 400, 500, 600 °C). Then pH, EC, carbon stability, ash and biochar performance were measured. In order to evaluate the effects of biochar resulting from different heat-treated temperatures on salinity tolerance of marigold, a factorial experiment was conducted in a completely randomized design in the greenhouse. The two factors studied included salinity levels (0, 4, 8 and 12 dS.m-1) and biochar resulting from different thermocouple temperatures (0, 300, 400, 500 and 600 °C). The biochar rate was considered to be 20%. One month after salinity treatment, seedlings were evaluated for osmotic metabolites activity and growth characteristics of marigold seedlings.

The results of ANOVA showed that all biochar properties were significantly affected by temperature factor. With increasing the pyrolysis temperature from 300 to 600 °C, pH and EC increased by 16.29% and 60.37%, respectively, and the ash content increased by 1.5 folds, but biochar performance and bulk density decreased by 52.28% and 48.1%, respectively. The highest carbon stability was observed at 500 °C, which increased by 20% compared to 300 °C. The results showed a significant negative effect of salinity stress on stem height, number and area of marigold leaves, so that with increasing salinity to 12 dS.m-1, 31.09, 17.28 and 45.7% decrease were observed in these traits, respectively. The physiological characteristics of marigold were significantly affected by the simple and interaction effects of salinity and biochar stress. In salinity treatments (0, 4, 8 and 12 dS.m-1) with increasing pyrolysis temperature from 300 to 600 °C 2.2, 2.04, 1.97 and 1.92 folds increase in leaf potassium concentration and 1.54, 2.26, 3.00 and 2.45 folds less than the control treatment in the amount of leaf proline was observed,  respectively. The activities of catalase, ascorbate peroxidase and guaiacol peroxidase enzymes were also significantly affected by the interaction of salinity stress and heat temperature. The highest enzyme activity in biochar was from 600 °C, which increased up to 8 dS.m-1 for catalase and up to 4 dS.m-1 for ascorbate peroxidase and guaiacol peroxidase.

In general, biochar salinity is its most important undesirable properties, which increases with increasing pyrolysis temperature, so the recommendation of biochar application in saline soils requires further studies. In the present study, the use of biochar under salinity stress did not have a significant positive effect on the development of marigold resistance and salinity stress tolerance.

The production and processing of medicinal plants is increasing day by day due to less side effects. The quality and quantity of medicinal plants are particularly affected by genetics, environmental factors and their interaction. Among natural limiting factors, water shortage is the most important factor that, especially in arid and semi-arid regions of the world, in various ways causes the restriction of planting and reduces the production of crops and medicinal plants. On the other hand, nutrients such as potassium can play an important role in plant resistance to environmental stresses. Therefore, this experiment was performed to investigate the effects of drought stress and potassium fertilizer on quantitative and qualitative characteristics and yield of German chamomile.

In order to investigate the effect of drought stress and different levels of potassium fertilizer on quantitative and qualitative characteristics of chamomile, a split plot experiment was conducted in a randomized complete block design with three replications in the Field of University Research Zabol. The treatments included drought stress in three levels, control (90% Field Capacity= FC), medium stress (70% FC), severe stress (50% FC) as the main factor and different levels of potassium sulfate fertilizer in four levels, non-consumption Potassium fertilizer (control), 50, 100 and 150 kg of potassium sulfate per hectare were considered as a sub-factor. The studied traits were as follows: plant height, number of stems, plant dry weight, number of flowers per plant, yield of dried flowers, essential oil content, potassium percentage, carbohydrate content, total chlorophyll, carotenoids and proline. Data analysis of variance was performed using SAS software and version 9.1. The mean of treatments was compared using Duncan's multiple range test at 5% level of probability.Results

The results showed that the effect of drought stress and potassium fertilizer on stem number, plant dry weight, number of flowers, carbohydrate and carotenoid content was significant. With increasing drought stress intensity to 50% FC, the number of stems and number of flowers per plant decreased by 36.08% and 39.57%, respectively, but with increasing drought stress intensity, the amount of carotenoids was 1.6 times that of non-stress treatment and the amount of carbohydrates 31.12% increase compared to non-stress treatment. The results showed that with increasing the amount of potassium fertilizer from 50 to 150 kg.ha-1, the number of stems and the concentration of carotenoids were 1.62 and 1.44 times, respectively, and the number of chamomile flowers per plant and the amount of carbohydrates were 30.52 and 41.20. Percentages increased. The results showed that plant height, dried flower yield, essential oil content, potassium percentage and proline were significantly affected by the interaction of drought stress and potassium fertilizer levels. With increasing stress intensity in all fertilizer treatments, a decrease in dried flower yield and an increase in proline content were observed. Application of potassium fertilizer had a significant positive effect on these traits under stress conditions so that by increasing the amount of potassium fertilizer from zero to 150 kg.ha-1 in severe drought stress plant height, dry flower yield, potassium and leaf proline, respectively. 2, 1.59, 2.64 and 1.95 times were control and the percentage of essential oil increased by 0.32%.

In general, it seems application of potassium within increase flower yield, can improve quantitative and qualitative traits of plant undser of drought stress, and decreased damages of drought stress

To study the effects of different levels of iron and zinc chelates application and supplementary irrigation on the quantity and quality of Ferula assa-foetida L. asafetida, a factorial experiment was conducted in a randomized complete block design with three replications in Neyriz City (Fars province) in 2018. The experimental treatments included the supplementary irrigation (no irrigation (control), once, and twice irrigation) and zinc and iron chelates foliar application (no foliar application (control), Zn (two per thousand) foliar application, Fe (two per thousand) foliar application, and combined Fe (1.5 per thousand) and Zn (1.5 per thousand) foliar application). The studied traits included the number of leaves, leaf length, crown diameter, aerial parts dry weight, plant survival percentage, concentration of elements Fe, Mn, Cu, and Zn in the aerial parts, asafetida weight, and essential oil content. The results showed that the supplementary irrigation increased the number of leaves, aerial parts dry weight, and survival percentage of the plant. Twice supplementary irrigation resulted in the highest aerial parts Fe content. Also, the iron and zinc chelates foliar application increased the leaf length and survival percentage of the plant compared to the control. The highest aerial parts Fe content was obtained by iron chelate foliar application. Under both supplementary and control irrigation conditions, the zinc and iron chelates foliar application significantly increased the plant volume by 1.5 times, asafetida weight by 2 to 2.8 times, and essential oil content by 0.6 to 0.9%. In addition, under no supplementary irrigation conditions, the highest aerial parts Mn content of the plant was obtained by zinc chelate foliar application as well as combined iron and zinc chelates foliar application, but under once and twice supplementary irrigation conditions, the foliar application had no significant effect on this parameter. Under both supplementary and control irrigation conditions, the highest aerial parts Cu content of the plant was observed in no foliar application treatment. The Zn foliar application caused the highest aerial parts Zn content of the plant. Therefore, it seems that the supplementary irrigation with the foliar application of iron and zinc chelates could increase the asafetida yield and essential oil content in F. assa-foetida by improving the growth characteristics.