جستجوی مقالات مرتبط با کلیدواژه « تنظیم اسمزی » در نشریات گروه « علوم پایه »

In order to investigate the biochemical respnces and performance of two vetch cultivars to tillage and salicylic acid in dry conditions, two vetch cultivars of Maragheh and Gachsaran were sprayed at four levels of salicylic acid 0, 0.5, 1 and 1.5 mM, were investigated as a split plot in the form of randomized complete block design with four replications in three environments including conventional tillage (ploughing with reversible plow and disc), low tillage (protection plowing with chisel packer) and no tillage. The results showed that the highest amount of proline in shoot was without significant difference from the low tillage method in Maragheh variety with the application of zero, 0.5 and 0.1 mM salicylic acid (5.8 mg/g fresh weight), and the lowest was obtained from conventional tillage method in Gachsaran cultivar with application of 0.5 and 0.1 mM salicylic acid (3.4 mg/g fresh weight). The highest amount of shoot peroxidase from the low tillage method in Maragheh and Gachsaran cultivars (without significant difference, 152 and 151 micrograms of protein per minute, respectively) and the lowest was obtained from the conventional tillage method in Maragheh cultivar without the use of salicylic acid (133 micrograms of protein per minute). The highest amount of raw seed protein from conventional tillage method in Maragheh variety with application of zero and 0.1 mM salicylic acid (29.2%) and the lowest amount was achieved from low tillage method in Gachsaran variety without application of salicylic acid (25.7%). The trend of changes in seed yield and shoot proline under the influence of salicylic acid showed that by increasing salicylic acid application up to 1.5 mM, these two traits increased by 10.5% and decreased by 12.3% compared to the control treatment. In total, the results showed that the reactions of biochemical traits to tillage, salicylic acid and variety were different, but the method of low tillage in Maragheh cultivar with foliar spraying of 1.5 mM salicylic acid by creating favorable conditions for growth caused a decrease in proline content and increased grain yield.

Salicylic acid priming and Chelat nanofertilizer (Parmis fertilizer 10) spraying can moderate the damage caused by drought stress in rainfed agriculture. In this research, which was carried out as a factorial-split in the form of a basic design of randomized complete blocks with three replications in Khorramabad, the effect of these two factors on two chickpea cultivars was investigated. The results showed that the local cultivar of Grit had more proline, peroxidase, and photosynthetic pigments in shoots, and the amount of copper and manganese in seeds was higher than that of the Adel variety. However, the amount of shoot catalase and the amount of potassium and magnesium in the seed were superior in the Adel variety compared to the local cultivar of Grit. Salicylic acid increased catalase, chlorophyll a and chlorophyll a+b by 1.8%, 6.7% and 5.4%, respectively, and decreased the amount of phosphorus by 1.7% compared to the control treatment. Nanofertilizer up to three liters per hectare reduced the amount of proline, peroxidase, chlorophyll a, chlorophyll a+b and the ratio of chlorophyll a/b in the aerial parts, but on the amount of catalase and chlorophyll b in shoots and potassium, magnesium, iron, copper, manganese and zinc in the seed. The interaction effect of variety and salicylic acid and nanofertilizer was significant for all traits measured in the shoot. With the increase in foliar application of the nanofertilizer, the amount of seed protein showed a linear increase, but the protein yield of chickpea showed a significant increase up to the level of two liters per hectare and then decreased. In general, the Adel cultivar with salicylic acid priming and foliar spraying of 2 liters per hectare of nanofertilizer improved the quantity and quality of chickpeas in rainfed conditions.

The main purpose of the recent study was to evaluate gill chloride cells in Cyprinus carpio during adaptation to different environmental salinities over a short period.

For this research, Cyprinus carpio by an average weight of 41.4±1 g and length of 16.9±1 cm in four groups with three replications was used. The first group as control was located in fresh water and the next three groups respectively were kept in 4 ppt, 8 ppt, and 12 ppt salinity with the exact condition. On 0, 6, 12, 24, 48, 72, and 96 h the second-gill arch with a maximum thickness of 0.5 cm from the left side was prepared and placed in formalin’s buffer 10%, glutaraldehyde 2.5% solution, and pH 7.4. Then the standard method of preparing tissue sections was performed and paraffin sections with a thickness of 4-6 microns were prepared and stained with hematoxylin and eosin methods and examined with a light microscope. Also, changes in the structure and number of mitochondrial-rich cells, distribution, and dispersion of Na+/K+-ATPase enzyme were studied by scanning electron microscope and immunohistochemical technique.

Results showed obvious modifications in the number and distribution of chloride cells in two filament and lamellar positions at different sampling times. The highest number of chloride cells in the filament and lamella, 26.28±1.33; 19.11±1.27 was reported in 12ppt and the lowest number belonged to the control group. The largest size of chloride cells in the filament and lamella, 22.51±1.56; 12.72±1.32 was reported in 12ppt and the lowest size belonged to the control group.

The findings of this study showed that C. carpio gill chloride cells in the face of different salinities in a short period can change the number and size and adapt to the new condition.

The Valerian plant (Valeriana officinalis L.) is one of the most important medicinal plants known in the world and native to Europe and Asia, which has been considered and used by humans in traditional medicine since ancient times. In this study, in order to evaluate the effect of inoculation with Funneliformis mosseae and drought stress on some characteristics, including growth parameters, osmotic adjustment and phosphorus uptake of valerian plant, a factorial experiment was conducted in a completely randomized design with 4 replications for two months. The experimental factors included two fungi levels (non-inoculated (control) and inoculated) and three levels of drought stress (90-100% (control), 60-70%, and 40-50% of field capacity (FC)). The results showed that drought stress significantly reduced the biomass, leaf relative water content, and phosphorus concentration of shoot and root at both 60-70% FC and 40-50% FC levels, and the chlorophyll content at 40-50% FC level. In this research, growth parameters, chlorophyll content and phosphorus concentration increased due to colonization with F. mosseae at both stress levels. Biochemical analyses also showed that the contents of soluble sugars, protein and malondialdehyde (MDA) in the shoots and roots of valerian significantly increased under drought stress. Mycorrhizal inoculation of valerian caused an increase in shoot protein at 60-70% FC level and conversely, it caused a decrease in the contents of soluble sugars and MDA in shoot and root and protein of root at both 60-70% FC and 40-50% FC levels compared to non-inoculated plants. In general, the colonization of valerian plants with F. mosseae by modulating the effect of drought stress could be a suitable and efficient method to mitigate the detrimental effects of drought stress on the symbiotic plants.

In order to investigate the effect of combined animal-chemical fertilizer and zeolite on the biochemical properties of two cultivars of red bean (Phaseolus vulgaris L.), a factorial experiment with three factors in the form of a randomized complete block design with three replications was implemented in climatic conditions of Azna city in Lorestan province in spring of 2016 and 2017. Cultivar factor included two cultivars Goli (creeping) and Akhtar (standing); Animal-chemical compound fertilizer agent in five levels including 100:0, 75:25, 50:50, 25:75 and 0:100 Livestock:chemical ratio and zeolite agent in four levels including non-application of zeolite and consumption of 3, 6 and 9 tons zeolite per hectare. Livestock manure was obtained from rotten sheep manure and chemical fertilizer was obtained from urea. The results showed that with increasing zeolite consumption, shoot proline decreased but grain yield (2199 kg / ha) increased. In both Goli and Akhtar cultivars, the highest amount of shoot iron (375 and 403 mg / kg, respectively), grain iron (102 and 111 mg / kg, respectively) and grain yield (2341 and 2630, respectively) Kg / ha) from 50:50 animal treatment: chemical and six tons per hectare of zeolite was obtained, but the highest potassium content of shoots (1.40 and 1.39%, respectively) in flower cultivar from 0: 100 animal treatment: Chemical and non-use of zeolite; While in Akhtar cultivar, 0: 100 livestock: chemical and six tons per hectare of zeolite were obtained. In total, Akhtar cultivar with the application of 50:50 animal manure: chemical fertilizer and six tons per hectare of zeolite is recommended to achieve maximum grain yield and grain enrichment.

The aim of the present study was to evaluate the osmoregulation ability of zander (Sander lucioperca) at two larval stages including before (group “a”) and after (group “b”) yolk sac absorption. Both groups were exposed to freshwater (less than 0.5‰ salinity), estuarine conditions (7‰) and Caspian Sea water (12‰) for 96h. Larva survival rate and chloride cell number, size and the its surface percentage were examined by classical histology using H & E staining and immunolocalization of Na+,K+-ATPase. Survival rate was 97% for both groups in freshwater and was 86% and 97%, respectively for group “a” and “b” at 7‰ salinity. At 12‰ salinity, all larvae in group “a” died while 20% of group “b” survived. The size of skin chloride cells did not change in the face of different salinity. At the end of the experiment, the number and the surface percentage of chloride cells significantly increased in the group “a” at 7‰ salinity and in group “b” at 12‰ salinity (P<0.05). The results showed that in the Caspian Sea zander larvae, the function of skin chloride cells in osmoregulation improved with development of body and it could act in such a way that the survival rate in the post-yolk sac uptake stage was more than the pre-yolk sac uptake stage exposed to salinity.

This experiment was conducted to investigate the effect of drought stress and vermicompost biofertilizer on some morphological, physiological and biochemical characteristics of Thymus vulgaris in greenhouse of Khorramabad Agricultural and Natural Resources Research and Training Center in a completely randomized design with three replications. The pot experiment was performed. Factors included vermicompost fertilizer levels at 0, 30, 50 and 70% of pot volume and water stress including post-discharge irrigation (85 (control), 70 (moderate stress), and 55 (severe stress). The moisture content was the field capacity. The results showed that with increasing drought stress, the amount of photosynthetic pigments (chlorophyll a and chlorophyll b), antioxidant enzyme catalase, protein, secondary metabolites of alpha-terpinene, thymol and carvacrol and morphological traits of plant height, number of sub-branches, fresh weight and dry weight of plants decreased significantly, but drought stress of antioxidant enzymes and hydrogen peroxidase significantly increased the amount of unstructured soluble sugars and amino acid proline. Increased consumption of vermicompost significantly increased chlorophyll b, hydrogen peroxidase, alphaterpinene, thymol, carvacrol, essential oil percentage, plant height, number of sub-branches, fresh weight and dry weight of plant, but chlorophyll a and unstructured soluble sugars reduced. According to the results of this experiment, with increasing the severity of drought stress, despite the plant's antioxidant defense and osmotic regulation, the production of most secondary metabolites and the growth of the thyme stress-sensitive plant decreased significantly; However, consumption of vermicompost increased secondary metabolites, growth and fresh and dry weight of the plant.

Drought stress is the most important factor of yield reduction in sugar beet. Therefore, adopting effective strategies for diminish of the drought adverse effects in sugar beet is necessary. This field experiment was conducted in order to study the effects of foliar application of potassium (K) and boron (B) on morpho-physiological responses, quality and root yields of sugar beet (Beta vulgaris L.) under drought stress conditions, using a split plot experiment based on randomized complete block design with three replications, in Shahrekord University, in 2019. The main plots were allocated to irrigation treatments including: irrigation after 70, 100 and 130 mm (I1, I2 and I3, respectively) cumulative evaporation from class A evaporation pan and the sub plots were allocated to fertilizer treatments in the form of foliar spraying including: control (no fertilizer application), K, B and B + K. Results showed that the effect of irrigation, foliar spraying and interaction of irrigation × foliar spraying treatments was significant regarding to leaf area index (LAI), leaf proline content, relative water content (RWC), extractable sugar, sodium and potassium content of sugar beet. The highest value of LAI and RWC was related to interaction of I1 irrigation and B + K spraying treatments. The highest value of leaf proline content was obtained by interaction of I3 irrigation and K spraying treatments. The highest percentage of extractable sugar was observed in interaction of I2 irrigation and B treatments. In other words, I2 irrigation treatment slightly increased the percentage of extractable sugar, which did not have significant difference with I1 irrigation treatment. The lowest amount of root sodium and potassium content was obtained under interaction of I1 irrigation and B + K treatments. The effect of irrigation and foliar application treatments on total plant dry weight, chlorophyll index, extraction coefficient of sugar (ECS), sugar and root yield was significant, as the highest amount of mentioned traits were recorded in B + K and I1 irrigation treatments. Interaction of irrigation×foliar spraying did not have a significant effect on these traits. Alkalinity coefficient was only affected by foliar spraying treatments and the highest amount of alkalinity coefficient was observed in K fertilizer treatment. Generally foliar application of B and K significantly improved the morpho-physiological, quantitative and qualitative properties of sugar beet and reduced the adverse effectss of drought stress, probably due to the important role of these elements in the osmotic adjustment and other plant physiological and biochemical processes. Therefore, in sugar beet cultivation especially under drought stress conditions, spraying of B and K is recommended.Drought stress is the most important factor of yield reduction in sugar beet. Therefore, adopting effective strategies for diminish of the drought adverse effects in sugar beet is necessary. This field experiment was conducted in order to study the effects of foliar application of potassium (K) and boron (B) on morpho-physiological responses, quality and root yields of sugar beet (Beta vulgaris L.) under drought stress conditions, using a split plot experiment based on randomized complete block design with three replications, in Shahrekord University, in 2019. The main plots were allocated to irrigation treatments including: irrigation after 70, 100 and 130 mm (I1, I2 and I3, respectively) cumulative evaporation from class A evaporation pan and the sub plots were allocated to fertilizer treatments in the form of foliar spraying including: control (no fertilizer application), K, B and B + K. Results showed that the effect of irrigation, foliar spraying and interaction of irrigation × foliar spraying treatments was significant regarding to leaf area index (LAI), leaf proline content, relative water content (RWC), extractable sugar, sodium and potassium content of sugar beet. The highest value of LAI and RWC was related to interaction of I1 irrigation and B + K spraying treatments. The highest value of leaf proline content was obtained by interaction of I3 irrigation and K spraying treatments. The highest percentage of extractable sugar was observed in interaction of I2 irrigation and B treatments. In other words, I2 irrigation treatment slightly increased the percentage of extractable sugar, which did not have significant difference with I1 irrigation treatment. The lowest amount of root sodium and potassium content was obtained under interaction of I1 irrigation and B + K treatments. The effect of irrigation and foliar application treatments on total plant dry weight, chlorophyll index, extraction coefficient of sugar (ECS), sugar and root yield was significant, as the highest amount of mentioned traits were recorded in B + K and I1 irrigation treatments. Interaction of irrigation×foliar spraying did not have a significant effect on these traits. Alkalinity coefficient was only affected by foliar spraying treatments and the highest amount of alkalinity coefficient was observed in K fertilizer treatment. Generally foliar application of B and K significantly improved the morpho-physiological, quantitative and qualitative properties of sugar beet and reduced the adverse effectss of drought stress, probably due to the important role of these elements in the osmotic adjustment and other plant physiological and biochemical processes. Therefore, in sugar beet cultivation especially under drought stress conditions, spraying of B and K is recommended.

One hundred and eight yellow-fin seabream (Acanthopagrus latus) with approximate weight 110±20g, adapted to salinity 20 ppt for 14 days, then challenged suddenly to salinity 5 ppt, 12 ppt, 34 ppt and kept in these salinities for 7 days. Gill samples were taken at 0, 24, 48 hours and 7 day after transfer. At time 0 structure of gill was normal and no changes were recorded in distribution of gill constitutes. Area of chloride cell increased in all groups after salinity challenge, but after one week at 12 and 34 ppt salinity, area of chloride cell decreased. Gill microscopic structure was normal and no changes was recorded in arrangement of the gill components. Size of chloride cell showed increase in fish kept in changed salinities, but decreased in 12 and 34 ppt groups after one week. Some changes including hypertrophy and hyperplasia of gill epithelium, lifting the gill epithelium, hypertrophy of chloride cells, changes in chloride cells area, adhesion Lamella and had an aneurysm were recorded in all groups. Our findings showed that some structural changes was seen in gills of A. latus to be compatible with different salinities

Osmotic stress such as drought, salinity, and cold is one of the most important stresses. The aim of this study was to isolate and evaluate the genes of AREB and MPK2 in order to study the resistance to drought of tomato plants. In this experimental study, seeds of two varieties of Tomato (Red Cloud) and (Peto Pride; resistant and susceptible to drought stress, respectively) were grown in drought treatment levels of -2 and -4. This study used 3 replications by a model based on a completely randomized block design. Sampling was done for Thiobarbituric acid reactive material (TBARM) for each treatment in 3 replications. Randomized and repeated sampling were done for molecular studies and the genes expression. AREB1 and MPK2 genes were studied, using bioinformatics resources and with the help of specific primers, making cDNA, PCR, and Electrophoresis. The analysis of variance test and SPSS 15 software were used Findings: With increasing drought stress, most of morphological traits had a considerable decline, but cellular oxidative index increased with the increase of stress, so that TBARM increased. The expression of AREB1 was higher than that of MPK2 gene expression. The rate of similarity between LeAREB and kinase 2 protein sequences in resistant tomatoes was 31%. With increasing drought stress, most morphological traits have a significant decline, but TBARM shows a significant increase with increasing stress. The AREB1 resistant drought gene is induced by the effects of drought stresses, while the expression of the MPK2 gene does not show a significant difference.

Serpentine soils are dry and contain rather high levels of nickel (Ni).To obtain a better understanding of drought tolerance by Ni in serpentine plants, a hydroponic trial was designed to compare the effects of Ni on growth factors, Ni uptake or translocation and some physiological parameters in the serpentine plant, Fortuynia garcinii (Burm.f.), under PEG simulated drought stress (3 levels). After 45 days, half number of vessels received 10 µM Ni for 8 days, and then plants ± Ni were exposed to drought stress for 8 days. The result indicating Ni treatment improved only slightly RWC, and Ni accumulation of root was consistently higher than shoot. The main reason for this action related to low translocation factors for this metal that showing this plant was more tolerant to plant-internal Ni. Photosynthetic pigments increased under drought stress treatments, but the treatments with Ni were consistently lower in compare same treatments without Ni in this serpentine plant. Phenolic compounds, water soluble carbohydrate, Glycine betaine and proline were also increased by Ni application under PEG simulated drought stress indicating that Ni improved the osmotic adjustment ability and enhance the antioxidant capacity. It is hypothesized that Ni could improve the drought tolerance of the serpentine plant by enhancing water utilization capability, osmotic adjustment and the abilities of antioxidative defense.

In many plants, glycine betaine acts as an osmotic protectant and osmolyte. But some plants, such as the tomato, are not able to synthesize and accumulate this osmolyte. This study was designed to investigate the effect of exogenous application of glycine betaine in reducing drought stress in tomato plants. Water stress in three levels (0, 3 days and 5 days without irrigation) and glycine betaine in three levels (0, 25 and 50 mM as foliar spraying) was applied. water stress in the both levels reduced the third leaf area, shoot dry weight, percent water content of the third leaf, the amount of chlorophyll, carotenoids, proteins, phenolic compounds and anthocyanins and increased lipid peroxidation, proline, reducing sugars and total ascorbate. However, application of glycine betaine in two levels, decreased lipid peroxidation, proline content and increased the amount of chlorophyll, carotenoids, reducing sugars, proteins, phenolic compounds, anthocyanins and total ascorbate and thus, increased the third leaf area, shoot dry weight and percentage of third leaf water. The results of this study showed that, exogenous application of two levels of glycine betaine in tomato plants, unable to synthesize this substance, is effective in reducing the effects of drought stress and improve growth parameters under stress and non-stress conditions.

This study aimed to investigate the alteration of compatible osmolite contents (including the content of reducing sugars and proline), as well as polysaccharides 4 wheat cultivars under water deficit conditions, this study was conducted in the field condition. Treatments were water stress and wheat genotypes that studied in a split plot experiment in RCBD design with three replications. Water stress treatments were done as cutting irrigation from anthesis period and optimum irrigation. Studied cultivars were Marvdasht (sensitive), Pishtaz and Bahar (semi-resistant), WS-82-9 (resistant). The results showed that the lowest decrease in grain yield was observed in WS-82-9 due to water stress in the grain filling period, the data did not reveal a significant difference among other cultivars (30% vs. 35-43% in the other cultivars). Biochemical studies showed that water stress caused accumulation of proline content in flag leaf, (21-20 μg/g FW in the control plants versus 57μg/g FW in WS-82-9 or 83 μg/g FW in Bahar cultivar, on the 6th days after drought stress). Over time, the difference between leaf proline content of the varieties were decreased in terms of water availability and water stress. Changes in the percentage of soluble sugars and proline contents showed the same trend. According to our results water stress caused to increased levels of soluble sugars in the stems especially in Marvdasht and Bahar cultivars and WS-82-9 line. Increased levels of soluble sugars occurred at the middle stage of grain filling in the flag leaf of Bahar and Pishtaz cultivars and WS-82-9 line, also this was occurred in Marvdasht at the late stage of grain filling. Polysaccharide content of the leaves and stems decreased in all cultivars by Water deficit, especially in susceptible varieties (highest decrease was observed about 0.52% and 0.67% respectively in leaves and stems of Marvdasht and Pishtaz and the lowest was found about 0.31% and 0.37% respectively in leaves and stems of Bahar and WS-82-9. It seems that compatible osmolites and proline accumulation (osmoregulation) is a common response of all wheat genotypes to drought stress but the rate of increase in these compounds was higher in resistant cultivars during stress

In order to study the effect of water deficit stress on some physiological characteristics including leaf water osmotic and turgor potentials and osmolytes including sugars, proline and invertase activity of Persian melon (Cucumis melo Group. cantaloupensis cv. samsoury), an experiment was conducted in complete randomized design. Treatments including three irrigation levels (start of irrigation at -50 (control), -65 (moderate stress) and -75 kPa (severe stress) of matric potentials. Severe decrease of osmotic potential even less than predicted value (about -23 bar) was happened in severe water deficit stress (start of irrigation at -75 kPa of matric potential). Results indicate that water deficit levels in this experiment were cause to changes in sugars content and invertase activity. Water deficit stress decreased invertase activity to 2.01 at 35th days after start of stress, while the activity of this enzyme at this stage was measured about 4.14, for control (start of irrigation at -75 kPa of matric potential). Severe level of water deficit (start of irrigation at -75 kPa of matric potential) increased fruit sucrose content (0.32 mg/g FW) and glucose content (0.08 mg/g FW), leaves proline content (0.35 µmol/ g FW) at 35th days after start of stress. Also, an osmotic regulation was happened in this plant by sucrose and proline aggregation under water deficit stress and according to the leaf osmotic potential has decresed even more than expected value.

The effect of salinity stress on theþ þhaematological and serum biochemical parameters of Persian ýsturgeon (Acipenser persicus) juveniles fed with different levels of Nucleotide-supplemented diet ýwas examined in this study. Fish (42.37± 2.12 g and 23.67± 0.61 cm) randomly were divided to ýfour treatments with different levels of dietary nucleotides (0, 0.25, 0.35 and 0.5 % diet). After 10 ýweeks feeding, salinity abruptly increased to 12 ppt. Serum biochemical and blood parameters were ýmeasured at 0, 12, 24, 48, 72 and 120 hours after salinity stress. One-way ANOVA using the ýresults significantly in the Spss 18 software was used for analysis. Duncan test was used for mean comparingý. After 12 hours after salinity ýstress, control group significantly showed the lowest values of total protein, albumin and ýeosinophil, and highest value of magnesium while the highest value of albumin found in group fed ýý0.50 % NT. 24 hours after salinity stress, treatments fed 0.35 and 0.50 % NT, significantly showed ýthe highest values of Hct and RBC. Also the lowest eosinophil was seen in treatment 0.50% (P ≤ ýý0.05). 48 hours after salinity challenge onset, glucose and MCHC in control group significantly ýshowed the highest values compared to NT-treated groups while there was a significant decrease in ýcalcium as NT level increased. The Mg value, 72 hours later, was significantly higher in treatment ýý0.50%. Finally, in the last blood sampling (T120), the lowest value of heterophil was found in ýtreatments 0.35 and 0.50 (P ≤ 0.05).ý

BACKGROUNGDS: Polycyclic Aromatic Hydrocarbons are environmental organic pollutants those may have destroying effects on aquatic organisms and aquatic ecosystems.
The present study investigated effects of Benzo alpha pyrene (BaP) as one of the most important hydrocarbons on gill structure and plasma cortisol levels in Yellowfin Seabream, Acanthopagrus latus.
Fish were divided to base, control and treatment groups. Treatment fishes received 50mg Bap per kilogram body weight dissolved in10µl coconut oil per gram body weight that were implanted peritoneal. Control group were implanted with coconut oil (10µl/g body weight) without BaP and whereas base group did not implant. Sampling was carried out 72 hours after implanting. At sampling time fish were anesthetized then blood and gill arch were sampled. According to the results plasma levels of cortisol significantly increased in both control and treatment groups. Histological investigation of the gill tissues showed intensive damages under BaP exposure stress.
Bap exposure stress caused some alteration in plasma cortisol levels and increasing gill histopathological lesions. So according to the importance of these parameters for some vital process such as osmoregulation and respiration, consequently disorders in hydromineral balance and survival is expected.

Cortisol is a corticosteroid hormon which has important effects on osmoregulation in marine fish. In this study the effect of oral cortisol on resistance (salinity stress in 12ppt during 7 days) in common carp (cyprinus carpio) fry was investigated. For this purpose، common carp (1. 36±0. 12 gr) was distributed in 3 treatments and 1 control group in 3 replicates and fed with commercial food containing 0 (control)، 50، 100 and 200 mg kg-1 food hydrocortisone during 8 weeks. At the end of the trial، hematocrit، biochemical blood parameters (glucose، calcium and total protein) and resistance of fish were determined. The results showed no significance in survival rates between treatments (p>0. 05). Glucose levels in the control treatment was significantly lower than other treatments at the end of the trail by serological investigation (p<0. 05). Fish were let in salinity stress and after 7 days all treatments showed a significant increase in the value of glucose (p<0. 05). The highest value of glucose was observed in fish on fed 100 and 200mg hydrocortisone per kg-1 food)73. 04±1. 40) (p<0. 05) and the highest level of haematocrit was observed after stress in the control group (61. 67±2. 08) (p<0. 05). Calcium Ionic factor showed a significant increase in all treatments except for the control treatment (11. 17±0. 31) (p<0. 05) and the highest value was observed in fish fed 200 mg hydrocortisone per kg-1. Total protein in fish treat-cortisol was significantly lower than the control group (p<0. 05). The results of this study showed that oral administration of cortisol can improve the salinity resistance in the common carp fry.

The study of the influence of serum indices can be a good indicator to assess the toxicity of pesticides in the environment. In this study¡ the effects of Fenpropathrine on plasma Na¡ K and cortisol level of common carp¡ Cyprinus carpio was investigated. The acute toxicity concentration (LC50) was determined for 96 hours according to O.E.C.D (1989) standard method. Then fish specimens were exposed to 5¡ 10 and 20% of LC50 (14µg/l) and also control group with three replicates. In each treatment¡ 54 healthy fish specimens (mean standard length: 7.8±0.6cm; mean weight: 10±1.2 g) were used. Sub lethal experiment was conducted for a period of 14 days and blood sampling was collected at 1¡ 7 and 14th day post exposure time. Plasma Na¡ K and cortisol levels were measured. The results show that plasma K levels of the exposed specimens increased and levels of plasma Na decreased significantly. Plasma cortisol levels increased in all treatments compared to control during the first day¡ and then decreased gradually. In conclusion¡ Fenpropathrine have direct effect on common carp stress and osmoregulation mechanisms.

One of the negative effects of water stress on growth and crop production is micronutrient uptake reduction by plant root. Therefore، to evaluate the effect of foliar application of Fe and Zn on some physiological and morphological characteristics of red bean (Akhtar cultivar) under drought stress this experiment was designed as a split plot in a completely randomized block design with three replications. Irrigation as the main plot at three level: Irrigation after 50، 75 and 100 mm evaporation from pan evaporation، and foliar application of micronutrients as the sub-plot at four level: foliar application with water (control)، ferrous sulfate، zinc sulfate and a mixture of ferrous sulfate and zinc (each at a concentration 3/1000) was used. The results showed that delay in irrigation decreased leaf relative water content، chlorophyll content، plant height، number of lateral branches and seed yield and increased electrolyte leakage، leaf prolin and soluble sugar content in compared to control treatment. The effect of foliar application treatments was significant on all traits except leaf soluble sugars and plant height. The foliar application of Fe and Zn increased leaf relative water content، chlorophyll content، number of lateral branches and grain yield، and decreased electrolyte leakage and leaf prolin significantly. According to the results the foliar application of Fe and Zn improved physiological characteristics and stress tolerance in plants. Therefore، the plants were delayed in encountered with water stress condition، and produce a better performance.

To regulate of body fluids in the marine elasmobranches¡ blood urea level is usually high. However¡ this condensation is toxic to other vertebrates. In this investigation¡ 36 individuals of brown banded bamboo sharks (Chiloscyllium punctatum) were sampled from Darvish Creek in the north of Persian Gulf. Blood samples were taken from fish and then weighing¡ biometry and the numbering of sharks were done. The results showed that the mean of urea in blood of shark Brown banded Bamboo sharks is 196/7 ± 30/2 mM. Additionally¡ significant relationships were found between the electrolytes with urea (P