فهرست مطالب elham faghani

Currently, in most countries around the world, cotton seeds are used in delinted form. The fuzzy cotton seed often lead to slower germination, increased susceptibility of seeds and seedlings to pests and diseases, and disrupts mechanized cotton planting. Delinted cotton seeds have numerous advantages, including the possibility of mechanized planting, reduced seed consumption per unit area, faster germination in the soil, and more rapid field emergence of seedlings. Furthermore, delinted seeds are usually free from pathogenic agents, and the seed quality is improved with the availability of gravity separation and removal of broken, lightweight, and hollow seeds. One of the challenges faced by cotton seed delinting factories in Iran that employ acid-based methods is the reduction in the seed germination of the delinted seeds, which poses a challenge to the continued operation of these factories. This research was conducted to investigate the reasons behind the reduction in the viability cotton seeds in a delinting factory, to examine the physiological and mechanical characteristics of seeds at various stages of delinting in the factory.

Seed sampling was carried out in a delinting factory in two replications. Traits such as seed vigor, germination percentage, ion leakage, seed density and volume, seed aging, level of abrasion and damage to the seed coat, and seed rupture force were studied. Finally, the data were analyzed using SAS, SPSS, and JMP software.

The test results showed that seed sampling from both replications of the factory before centrifuge had the lowest germination percentage, leaf formation percentage, primary root length, primary stem length, dry weight of primary root, and dry weight of primary stem. These traits indicate that during the centrifugation stage, the seeds sustain significant mechanical damage, leading to a reduction in their vigor. The percentage of breakage, ion leakage, ageing, volume and density of seeds in the first repetition showed that these seeds had a lower quality compared to the seeds related to the second repetition. Therefore, different delinting stages in the factory have decreased the seed vigor. As the percentage of breakage and ion leakage increases, the seed rupture force declines non-linearly. Based on these findings, it can be concluded that acid contact with the cotton seed and the centrifugation process caused more mechanical damage to the seeds, leading to a significant reduction in seed rupture force.

The accuracy of operations at all stages of delinting significantly impacts seed quality. The centrifugation stage, the temperature of the dryer cylinders, and the acid neutralization process require greater attention and monitoring. Therefore, it is necessary to adjust the duration or concentration of the acid used for delinting in the delinting factory to match the seed condition in order to minimize damage to the seeds.

Due to the increase in the consumption of fossil fuels and chemical fertilizers, especially nitrogen-containing fertilizers, the entry of nitrogen into the cycle of ecosystems has been more than normal.Nitrogen deposition as a consequence of increasing nitrogen input to the atmosphere, can be a threat to ecosystems. It can affect soil properties, soil microorganisms and their activities, vegetation and animals. The aim of the present study is to investigate the effects of deposition of different rates of atmospheric nitrogen on the biochemical properties of a summer rangeland's soil.

For this purpose, the seeds of Medicago sativa were planted in 36 pots containing rangeland soil in a completely randomized block design.  Two months after seed germination in pots, six Nitrogen treatments included control,30, 60,90,120 and 150 kg ammonium nitrate/ha which dissolved in water were applied in 6 replications during a period of 75 days. At the end of experiment, some soil biochemical properties (acidity, electrical conductivity, absorbable phosphorus, total nitrogen, organic carbon and exchangeable potassium along with biomass and microbial respiration) and Root weight and depth factors were measured.  Data analysis was done using analysis of variance method and mean comparison was done using Duncan's test.

The results demonstrated that increasing the level of ammonium nitrate deposition to 60 and 90 kg per hectare per year, despite the significant increase (p < 0.05) of organic carbon and total soil nitrogen, causes a significant decrease in other measured biochemical properties of the soil (p < 0.05). An increase in nitrogen deposition in the early stages may be partially responsible for root growth, but with nitrogen saturation in the soil and the occurrence of nitrate leaching, as well as the loss of soil fertility, unfavorable conditions for root growth are provided. With the increase of nitrogen deposition in the soil, up to the level of 60 kg /ha, the average respiration and microbial biomass increased, But at higher levels of  nitrogen deposition, respiration and microbial biomass decreased.

In case of an increase in mineral nitrogen deposition in the studied area, it is recommended to use the Medicago sativa in the improvement of vegetation restoration projects of summer rangelands to absorb the deposed mineral nitrogen in excess of the soil holding capacity, its alleviate negative consequences and creating a suitable root zone for the the  activity of soil microbial.

Cotton scientifically known as Gossypium hirsutum L. is a dwarf plant from the Malvaceae family and from the Gossypeae clan, that is native to tropical and subtropical regions. Cotton is one of the most important sources of oils globally and is rich in fiber and protein. It can also be used as animal feed. The purpose of this study was to compare the primary and secondary metabolites of the seed of two species, G. hirsutum L. and G. arboreum L. Compounds such as flavonoids, alkaloids, tannins, saponins, and steroids were detected in the two types of cotton. The biochemical properties of gossypol, flavonoid, flavonol, phenol and the antioxidant capacity of the cotton-seeds were evaluated. The results of the study indicated that G. arboreum L. as compared to G. hirsutum L. is valuable for use as animal feed and oil extraction, due to its higher amounts of fat, fiber and protein. A comparative study of the two species showed that both species had high antioxidant capacity and gossypol levels. Type G. hirsutum L. has greater quantities of phenol and flavonol than G. arboreum L. which can lead to the use of this species for breeding purposes and the creation of resistant strains to biological stress. The presence of large amounts of gossypol in the studied species indicates that consideration should be given for their utilization in various applications in the food and feed industry.

The salinization of soils and the optimal use of this vast area, the search for a suitable solution for the cultivation of a suitable crop is a priority of research. The cotton plant is semi-tolerant to salinity, but depending on the extent of species diversity, the yield alone cannot provide a reasonable indication of stress tolerance. Therefore, the study of biochemical and physiological characteristics of different species should provide comprehensive information on the cultivation and distribution of different species at different salinity levels.

The objective of this study was to evaluate the potential of different cotton species at different salinity levels. 8 species of Delinting cotton seeds, including G. herbaceum, G. arboretum, G. hirsutum, and G. barbadense, were grown in three replicates in large nylon pots using a randomized complete block design with three non-salinity levels (less than 4 dSm-1), medium salinity (8-9 dSm-1), and high salinity (12-13 dSm-1).

The results showed that at high salinity, non-phenolic compounds and phenolic content were highest and lowest, respectively, in the seed coat of Dr. Omumi and Golestan cultivars. At high salinity, the phenolic content of the seeds was highest in the Golestan cultivar. The lowest amount of tannin in the seed of Sepid cultivar was at salinity of 8 to 9 dSm-1, which decreased by 3.9%, 8.7% and 5.6%, respectively, compared to Dr. Omumi, Barbadens and Kerman indigenous cultivars at this salinity. Arbariums had the highest and lowest glycine-betaine concentrations at 8 to 9 dSm-1 and Mehriz at 12 to 13 dSm-1, respectively. At moderate salinity, protein concentration was highest in seeds of Mehriz variety. The protein concentration in the seeds of Golestan variety at both salinity levels and Dr. Omumi variety in non-saline environment increased significantly compared to the other varieties. At high salinity, the leaves of the Golestan cultivar had the lowest wax concentration among all cultivars, while at medium salinity the greatest wax accumulation was observed in the seed coat of the Golestan cultivar. The Golestan variety showed the highest proline concentration in the leaf at high salinity. The highest and the lowest proline content in the root were observed in Termez 14 at high salinity and in Dr. Omumi at medium salinity. At 8-9 dSm-1 salinity, Mehriz and Barbadens cultivars had the highest seed and fiber weight, respectively, while the lowest seed and fiber weight was recorded in Arbarium cultivar.

At 12-13 dSm-1, the cultivars Arbarium and Bomi-kerman had no bolls. It appears that the Golestan cultivar is the most tolerant to salt stress compared to other cultivars because it contains more proline, tannin, phenol, and wax. The varieties Bomi-kerman and Sepid, which stop flowering at high salinity, are also sensitive to 12-13dSm.-1

The most important element in the implementation of cotton IPM is the use of healthy seeds with high vitality. In a few years, cotton seed bugs have significantly increased their population in cotton fields and affect the quantitative and qualitative properties of seeds by feeding on them. Adults and nymphs of Oxycarenus hyalinipennis Costa feed on the contents of cottonseed, resulting in a loss in seed weight, germination rate, oil, protein and nitrogen content. The activity of the genus Oxycarenus on cotton fibers disrupts the ginning process and causes spotting, soiling and reduced quality of cotton fibers. Insect pests are important factors that reduce the yield of cotton crops. Proper control in the field requires adequate knowledge of the species of pest, its biology and the extent of its damage to the cotton plant.Due to the increase in the population of seed bugs in cotton fields in recent years, it was necessary to determine the biological characteristics, the predominant species of these seed bugs and their impact on the quantitative and qualitative characteristics of the seed and was investigated in this study.

For this purpose, a study was conducted in 2016-2017 in which seed bugs were collected from the cotton fields of Hashemabad Cotton Research Station and sent to Insect Classification Research Department of Iranian Plant Protection Research Institute to identify and confirm the genus and species. The insects were cultured under laboratory conditions. Biological factors of the insects such as adult life span, total nymphal life span, pre-oviposition period, oviposition period and total life cycle were evaluated. Morphological characteristics such as length, width and weight of adult male and female insects were also studied. To study the effects of the pest on the physiological characteristics of the seeds during the period of boll opening in the cotton field, 45 bolls were randomly isolated and covered with paper bags, and 45 marked bolls were naturally exposed to the pest. The seeds were sampled in the field in three stages at intervals of ten days. Necessary investigations on quantitative and qualitative characters of the seeds were carried out in the laboratory of the institute.

The seed bugs were identified under the scientific name Oxycarenus hyalinipennis Costa (Hemiptera: Oxycarenidae). Laboratory studies on insect biology revealed that adult longevity, total nymphal duration, pre-oviposition time, oviposition time, and total life cycle Mean (±SE) 32±2.20, 13.6±2.08, 10.69±1.35, 19.16±2.27, and 30±2.47 days, respectively. The results showed that the average weight of cotton seeds was highest in isolated bolls with an average of 10.71 grams. Thus, the average weight was 1.33% and 27.1% higher than plants whose bolls were not isolated and cotton seeds exposed to beetles, respectively. In isolated cotton seeds in the field, 20.5% less soluble carbohydrates and 59.1% less phenols were observed than in seeds exposed to pests.

When the population of cotton seed bugs increases, this pest can significantly damage the cotton crop by reducing the potency and other quantitative and qualitative properties of the seeds.

Study of water stress effect in traits of crops is related to stress tolerance, increasing their growth and yield in stress situation.This research was performed to evaluate the impact of different irrigation regimes on cotton yield, fiber quality were conducted using a split-plot factorial design with four irrigation levels (rainfed, 33%, 66% and 100%) as the main factor. After physiological maturation, fiber performance and quality traits were evaluated.protein and phylogenetic properties have been evaluated by bioinformatics tools. The results indicated that the highest yield with 1.2 kg was observed in 66% irrigation treatment. The highest fiber weight was observed in 66% treatment and the lowest in rainfed conditions. Seeds grown under 66% irrigation saved more water and produced potential seeds with high quality fibers. Bioinformatics analysis also revealed that the intracellular locations of CesA and XET1 enzymes are plasma membrane and cell wall, respectively. The enzymes CesA and XET1 belong to the protein family of transferases and hydrolase, respectively. Phylogenetic analysis revealed that the sequences of both cotton enzymes with co-family genera were separated in the Malvaceae . It appears that in order to grow cotton seeds with desirable fibers in low water conditions and in dry areas, it is better to use seeds that are irrigated under optimal irrigation conditions (66%). by cultivating cotton seeds with about one third of the water requirement in three years, in addition to reducing the amount of water requirement and irrigation water consumption, better yields can be achieved.

Climate change has made it difficult to access water resources. Therefore, induction of water stress tolerance in seeds production can make a great revolution in agriculture by achieving optimal yield and potential seeds, while reducing water consumption. This research was conductedwith aime of evaluation the physiological potential of cotton seeds obtained from different irrigation treatments in order to cotton seeds reproduction for farm of Golestan province in water stress exposure. The experiment was done in splite plot factorial in complete block design with three replications during 1396-97 crop- season. Main plot includes of 4 irrigation levels including rainfed, 33, 66 and 100% of field capacity and the sub-factor also includes the seed resources treatments in 5 sub-plots including control (supplyment of seeds from sales centers) and 4 seed levels obtained from different levels of irrigation (rainfed, , 66 and 100% of crop capacity) were considered.The results showed that the effects of number of being in water stress exposure for seeds on physiological characteristics and yield of plants were significantly different. In 33% water stress exposure, S22seed resources had the lowest and the most starch and carbohydrate solution,36.62 and 65.97 mgFw-1. So, 33% FC irrigation was not water-deficiency stress for S22. Decreasing in leaf area of S23 seed treatments in the double water stress exposure in rainfed and 100% FC conditions indicates that both rainfed and heavy irrigation are stressful for S23.

To study the effect of interval irrigation and growth regulators on morphophysiological traits of cotton cultivars, an experiment was conducted as a split factorial in randomized complete block design in 2017 and 2018 in Hashemabad Cotton Research Station in Gorgan, Iran. Treatments consisted of intervals of irrigation at two levels (two weeks and four weeks) as the main factor and six-level growth regulator treatments (control, benzyl adenine, abscisic acid, salicylic acid, brassinosteroid, and cycocel) and three cotton cultivars (Golestan, Kashmar, and Shayan) were also considered as sub-factors. The results of this study showed that proline content and relative water content of leaf decreased with water deficit stress. Maximum proline content (3.55 µg/g fresh weight) was obtained from Shayan cultivar with salicylic acid. Benzyl adenine and brassinosteroids increased relative leaf water content. The highest cell membrane stability (2.998%) was observed in Kashmar cotton cultivar and two-week interval irrigation, and Cycocel increased the membrane stability by 15%. Plant height, number of flowers, and number of bolls were affected by growth regulators, irrigation intervals, and cultivars. With increasing irrigation period, plant height, flower number, and boll number decreased in all cultivars, but under drought stress, Golestan cultivar had more flowers and boll number than other cultivars. Cycocel, salicylic acid, and brassinosteroids significantly increased flowering of cultivars at both years and both irrigation intervals. Benzyl adenine and brassinosteroids increased plant height more than 7% and abscisic acid, cycocel, and salicylic acid decreased plant height compared with control. Application of abscisic acid reduced the number of bolls by 22% compared with the control. Overall, growth regulators, especially cycocel and salicylic acid, increased the morphophysiological traits of cotton cultivars indicating their positive effect on drought tolerance and it could play a role in moderating stress effects under stress conditions.

In order to investigate the effect of growth regulators on a number of morphological characteristics of cotton cultivars, the present research was conducted as a factorial experiment in a randomized complete block design with 3 replications at Hashemabad Cotton Research Station, Gorgan in 2016 and 2017. Factors included growth regulators treatments with 6 levels (control, benzyl adenine, abscisic acid, salicylic acid, brassinosteroid, and cycocel) and three cotton cultivars of Golestan, Kashmar, and Shayan. Growth regulators affected most traits. Cycocel produced the highest number of bolls per plant (13.4) and abscisic acid reduced the number of bolls by 25% compared to the control. Salicylic acid increased, and abscisic acid and cycocel decreased the distance from the first sympodia to the ground. The highest number of fifth sympodia nodes, respectively, with an average of 7.17, 7.09 and 7.07, was allocated to foliar application with salicylic acid, brasinosteroid and cycocel, and the lowest with 6.07 and 6.13 belonged to abscisic acid and benzyl adenine. Overall, salicylic acid and benzyl adenine were able to increase the internodes length and abscisic acid and cycocel to reduce it. Therefore, with the aim of selecting cultivars with higher boll number, it is possible to use growth regulator of brasinosteroid or cycocel, and Golestan and Shayan cultivars, but to select a higher early maturity percentage, salicylic acid or cycocel, and Kashmar and Shayan cultivars can be used. In general, it is possible to recommend the cycocel growth regulator and Shayan cultivar.

Drought is one of the most important abiotic agents that adversely affect the growth and development of plants. The arid and semi-arid regions where sesame (Sesamum indicum L.), as a relatively drought tolerant plant, is grown are specified by high temperatures. In order to evaluate the effects of paclubutrazul (PBZ) on the drought tolerant of sesame a factorial experiment were conducted based on randomized complete block design with three replications in 2014 at greenhouse of Educational Department of Kordkoy (Golestan province). Treatments included two genotypes of sesame (Yellow- white and Oltan), three levels of watering (20, 50 and 80% FC) and three concentrations of PBZ application (0, 7.5 and 15mg/L). Traits such as chlorophyll a, b and carotenoid contents, superoxide dismutase and peroxidase activity, yield and yield components were measured. Data were analyzed with SAS software. Results showed that genotype, water treatment and PBZ had a significant effect on chlorophyll a, b and carotenoid contents, superoxide dismutase and peroxidase activity of roots and leaves, yield and yield components. High PBZ application where plants exposed to the severe water stress significantly improved chlorophyll b (44%), superoxide dismutase of roots and peroxidase activity of roots and leaves. Yellow-white genotype showed higher chlorophyll a (30.4%), b (40.6%) and carotenoid concentration (29.9%), superoxide dismutase of roots (3times), superoxide dismutase of leaves (1.9 times) and peroxidase activity of roots (3times) in severe water deficit stress. Finally, it can be concluded that Yellow white responded better to drought stress than Oltan genotype with maximum levels of PBZ throughout antioxidant mechanismes.

Sesame (Sesamum indicum L) is a flowering plant in the genus Sesamum. It is widely naturalized in tropical regions around the world and is cultivated for its edible seeds, which grow in pods (Monayem Miah et al., 2015). Drought is one of the most important abiotic stresses which affect almost every aspect of plant growth. The arid and semi-arid regions where sesame is grown are specified by high temperatures, high evaporation demand and occurrence of unpredictable drought (Oscar Rojas et al., 2014). This plant is relatively drought tolerant. Resistance to water stress in sesame is important in many countries with low rainfall.
Material and In order to evaluation effects of Paclubutrazul on two Sesamum indicum genotypes under drought stress and study physiology, yield and yield component responses of genotypes, these experiment was done using factorial arrangement based on Randomized Complete Block with three replications in 1393-94 in greenhouse of educational department of Kordkoy. Treatments included Sesamum indicum genotypes (Yellow- white and Oltan), three levels of watering (20, 50 and 80% FC) and three concentrations of paclubutrazul application (0, 7.5 and 15 mgL-1). Data were analyzed with SAS software.
Finally results showed that genotype, water treatment and paclubutrazul on thousand seed weight, yield, proline, epicuticular wax of leaf, catalase activity of leaf and root, starch and carbohydrate soluble was significant. Although proline, EWL, catalase enzyme activity in leaf and root were declined, but Starch and carbohydrate solution content of leaf was elevated in Yellow- white against 20% FC. Application of paclubutrazul on starch, proline and catalase enzyme activity in both genotypes were not significant, but catalase enzyme activity in root, carbohydrate solution and EWL in leaves, thousand seed weight and yield were different significantly. Oltan in waterless stress had maximum proline content, EWL and catalase enzyme activity than yellow white, albeit, yellow white had highest carbohydrate solution than Oltan. Also EWL in leaves of Oltan was increased in 15mgL-1 paclubutrazul. EWL accumulation leaves protect them from addition water evaporation (Gonzalez et al., 2010). Also concentration of EWL accumulation leaves against severs waterless stress and highest paclubutrazul content, was highest 4 times than well water and without paclubutrazul usage. Catalase enzyme activity in root and leaves and proline content of leaves in 15 mg paclubutrazuland severe waterless stress were 9, 0.2 and 0.4 times more than without paclubutrazul and well water treatment. Carbohydrate solution in leaves under severe water stress and highest paclubutrazul content was 0.6 times more than control. In well water with 15 mg paclubutrazul, average yield per plant 13.3 g with thousand seed weight, 3.61g than control was highest in comparison control. Also, Oltan genotype than Yellow white to highest concentration paclubutrazul usage in case of effect on Osmolites and Catalase activity enzyme showed positive reaction.