جستجوی مقالات مرتبط با کلیدواژه « کربوهیدرات های محلول » در نشریات گروه « زراعت »

Barley (Hordeum vulgare L.) is among the most influential cereals, and a wide range of populations in several regions of the world (Sallam et al., 2019). However, there are some restrictions for accomplishment to the potential production, which the most consequential one among them, water shortage, a drastic obstacle in many regions of the world, in particular in arid and semi-arid areas. Water scarcity, results in plenty of disturbances in plant functions like cell division and elongation, water and nutrients relations, photosynthesis, enzymes activity, stomata movement, assimilate partitioning, respiration, oxidative damage, growth, and productivity, as several types of researches show that water shortage in the soil cause many disorders in plant tissues, which in turn leads to a punctual diminish in the photosynthesis rate (Todorova et al., 2022). Under circumstances of water shortage, the electron transport through PSII is prohibited, and the oxygen-evolving complex of PSII is damaged (Georgieva et al., 2005). In repercussion, depends on the times, duration of facing, and stress intensity, developmental stage, and kind of tissue, plant defenses against it differently.

An experiment as a factorial in a completely randomized block design in five replications at the experimental greenhouse of the University of Zanjan was carried out in two years 2021 and 2022. In this study two regimes of irrigation (D0, regular irrigation as the control, D1, Water Deficit for two weeks immediately after flowering), four levels of biochar (zero% as the control treatment, 0.25, 0.5 and 1 percent of soil weight) and three levels of spraying Methyl Jasmonate (zero μmol as the control treatment, 50 and 100 μmol) at the same time with flowering stage and starting withholding water, were executed.

Results demonstrated that utilized treatments had significant effects on studied parameters. Results illustrated that, despite the fact that proline content, carbohydrate and quantity of electrolyte leakage were elevated as a result of drought stress, and accumulation of photosynthetic pigments were dwindled, however, application of biochar in the soil and foliar spraying of methyl Jasmonate caused modulating the effects of drought stress. Lack of water can reduce the concentration of photosynthetic pigments, mainly chlorophylls and carotenoids, as it causes oxidation which leads to diminishing the biosynthesis of pigments (Pandey et al., 2012). It is claimed that using biochar ameliorates the reduction of pigments in stressed plants as a result of better surface area, higher water holding capacity, more cation exchange capacity, and useful absorptive features of biochar (Ibrahim et al., 2020). Moreover, the drought stress resulted in a substantial elevation in the concentration of proline (PC) which might be as a result of devastating impacts of drought on the performance of plasma membrane as well as the process which leads to dehydration of cytoplasm, which in turn results in boosting proline concentration in Barley plants under drought situation (Hafez et al., 2020). It is said that biochar reduces proline content, because of its impact on maintenance of plasma membrane in a stable situation, modulating the pressure of water in cell, and enhancing the ability of plants in conserving relative water content (Ahmed et al., 2016). Furthermore, methyl Jasmonate (MJ) may facilitate the strengthening of cell walls and effectively neutralize excessive increase in the level of ROS during further exposure to the stress factor, thereby preventing the damage of cellular membrane structures and changes in their permeability under stress conditions (Hayat and Ahmad., 2007).

The current study represents that Barley can tolerate drought stress through several mechanisms such as modulating some biochemical compounds. In this study drought was shown to have negative impacts on some of the studied physiological and biochemical parameters. Results demonstrated that the use of biochar and Methyl Jasmonate can improve the adaptation ability of Barley plants to water shortage, associated with enhancement in morpho-physiological and biochemical traits. Soil content of biochar at 0.25% w/w and Methyl Jasmonate leaf applies at 50 micro moles protected plants against drought stress. Importantly higher doses of biochar and Methyl Jasmonate had negative impacts, highlighting the need to better understand optimal doses, and mechanisms of action of these amendments.

Stems water soluble carbohydrates are one of the major sources of assimilates for seed filling in photosynthesis limitaton and drought stress. The objective of this study was to evaluate stem reserves accumulation capacity and its relationship with yield of wheat cultivars under cycocel (cycocel) treatments. 22 wheat cultivars were cultivated in a split plot design with three replications, cycocel foliar application and control (no cycocel) being main plots and wheat cultivars were sub plots. The amount of accumulation was estimated by measuring stem weight and stem soluble carbohydrates content (WSC). Significant variation among cultivars was observed under both cycocel and control treatments. Cycocel foliar application reduced stem length by 3.9% and increased stem specific weight by 6%. An increase in WSC content was observed in some cultivars with cycocel application. Cycocel, not only affected the distribution of photosynthetic assimilates between structural and soluble compounds in the stem, but also increased grain yield and number of seeds per spike. Cycocel increased the number of seeds per spike by 6% and grain yield by 8.2%. According to the results of cluster analysis, in both control and cyclool application treatments, Shabrang and Pishgam cultivars were the best cultivars in terms of studied traits. In conclusion, foliar application of cycocel in the second node emergence stage of wheat had a positive effect on grain yield and number of grains per spike and it aslo improved WSC accumulation capacity especially in taller cultivars.

Lentil (Lens culinaris Medik.) is an important legume that plays a significant role in food security and human nutrition in the world. Lentils provide protein and fiber, as well as many vitamins and minerals, such as iron, zinc, folate, and magnesium. Lentil is a moderately drought tolerant crop, but the yield is drastically reduced with increased drought stress. One of the simplest ways to reduce the effects of drought stress is regulate plant growth period to avoid moisture stress; termed as drought escape; therefore, autumn planting can be effective in reducing the effects of drought stress in lentile. On the other hand, cold and freezing are the most important factor limiting lentil cultivation in autumn planting. Considering the importance of autumn planting in cold and highlands areas to use the seasonal rainfall in lentile crop and also due to the diversity among lentil genotypes for cold tolerance and the importance of lentil as a source of high nutritional value, this study was conducted to identify cold tolerant lentils genotypes.

This research was carried out in order to investigate the effective traits in freezing tolerance of lentil genotypes, as factorial based on Completely Randomized Design with three replications under controlled conditions at Ferdowsi University of Mashhad in 2020. The studied factors included 18 lentil genotypes at four freezing temperatures (0, -15, -18 and -20 °C). The pots were irrigated 24 hours before the freezing stress and then transferred to the thermogradient freezer to apply the tretments in mid-February. The freezer temperature at the beginning of the experiment was 5 °C and after placing the samples with slope of 2 °C per hour the temperature decreased. In order to create ice nucleation in the plant and to avoid the supercooling phenomenon, at 3 °C, Ice nucleation active bacteria (INAB) were sprayed on the plant. In order to balance the ambient temperature, seedlings were kept in each temperature treatment for one hour and then overnight in a cold room at 5 °C. Before exposing the plant to freezing stress, photosynthetic pigments, DPPH radical activity, anthocyanin, total phenol, soluble carbohydrates, malondialdehyde (MDA), proline content, catalase activity, peroxidase activity, and the relative water content (RWC) of the osmotic potential were measured. Three weeks after transferring the samples to the greenhouse, the survival percentage of the samples were evaluated. Plant survival percentage was calculated by counting the number of live plants before and after frost stress in each pot.

The results showed that lowering the temperature to -18 and -20°C reduced the survival rate in most genotypes. The highest survival percentage was observed in MLC11 genotype at -18°C. None of the studied genotypes could withstand temperatures of -20°C. At -15°C, MLC13, MLC17, MLC70, MLC409 and MLC454 genotypes had a survival of over 80%. Factor analysis showed that the first factor accounted for 31.12% of the changes with chlorophyll a, carotenoids, Cha to Chb ratio, total photosynthetic pigments and inhibition of DPPH free radical activity and the second factor accounted for 18.28% of the changes with chlorophyll b, peroxidase, plant height and biomass justifies. Due to these traits, MLC8, MLC13, MLC17, MLC38, MLC84, MLC286 and MLC334 genotypes are considered as high stress tolerance genotypes. Analysis of genotype clusters and comparison of group means showed that all traits except soluble carbohydrates, proline, relative leaf water content, catalase and osmotic potential in the first group (MLC8, MLC11, MLC33, MLC47, MLC70, MLC84, MLC4, MLC409, MLC409) They were superior to the total average.

Significant variations were observed among the genotypes studied in terms of survival rate, regrowth, and antioxidant traits. Clustering and mean comparison analysis revealed that genotypes in the first group exhibited superior cold tolerance. These genotypes outperformed the overall average in most of the examined traits. On the other hand, genotypes in the second and third groups had lower mean survival rates compared to the overall mean, indicating their higher sensitivity to stress. The first group included genotypes MLC8, MLC11, MLC33, MLC47, MLC70, MLC84, MLC409, MLC454, and MLC472. Further investigations of these genotypes under field conditions are recommended to explore their potential and performance.

Salinity is a global challenge to crop production. Chickpea grow under a wide range of climatic conditions and is highly sensitive to salt stress. Salt stress causes osmotic, ionic and secondary stresses, impairing various metabolic processes in plants and eventually decreases plant yield. Using salinity tolerant chickpea cultivars could be effective in increasing production and productivity of saline fields due to their ability in biological nitrogen fixation. The aim of the present study was to evaluate the effect of salinity on physiological responses of 17 chickpea genotypes in seedling stage.

To determine the most tolerant genotype to salinity stress, a split plot experiment was conducted based on randomized complete block design (RCBD) with three replications in Ferdowsi University of Mashhad, Mashhad, Iran. 17 Kabuli chickpea genotypes as sub plot, two salinity levels (12 and 16 dS.m-1 NaCl) and a control (0.5 dS.m-1) as main plot were evaluated. Salinity stress was applied two weeks after sowing. Four weeks after salinity stress was imposed, traits including electrolyte leakage, photosynthetic pigments, total phenol, soluble carbohydrates, proline content, osmotic potential, survival percentage, sodium and potassium content of shoots and salinity tolerance index were measured.

In all genotypes, with increasing salinity stress level, survival percentage decreased and electrolyte leakage percentage increased. In the 16dS.m-1 NaCl treatment, MCC72, MCC108 and MCC112 genotypes had the highest survival percentage of 86.5, 82.6 and 100%, respectively. In salinity level of 16dS.m-1, MCC108 genotype showed the lowest percentage of electrolyte leakage (82%) and MCC12, MCC58 and MCC27 genotypes showed the lowest increase in the percentage of electrolyte leakage compared to the control. The chickpea genotypes showed different responses by increased salinity in terms of photosynthetic pigment content. In MCC92, MCC108, MCC112 and MCC296 genotypes, content of chlorophyll a increased as salinity level increased to 16dS.m-1. Soluble carbohydrates and proline content in all genotypes increased and osmotic potential became more negative as salinity levels increased from 0.5 (control) to 16 dS.m-1.

In general, there was a wide variety among chickpea genotypes based on physiological traits. The analysis of clusters of genotypes was divided into five groups. Cluster analysis and mean comparison showed that the survival percentage in MCC108 and MCC112 genotypes were higher than total mean, so supplementary field studies on these two genotypes are recommended.

An experiment has been conducted in the form of split plots in a randomized complete block design with three replications at the Agricultural and Natural Resources Research Institute in Zahak to evaluate the effect of drought stress and potassium application on yield and morphophysiological traits of safflower (Goldasht cultivar) under saline irrigation conditions (EC 6 dS.m-1) in 2018-2019. Drought stress irrigation regimes have been tested at three levels (irrigation after 45% (control), 65%, and 85% of admissible moisture depletion) as the main factor, and potassium fertilizer at four levels (0, 75, 150, and 225 kg.ha-1) as the sub factor. According to the findings, drought stress has reduced plant height, number of heads per plant, number of seeds per head, seed and biological yield, and relative water content. The use of potassium, on the other hand, has increased the above traits greatly. Irrigation after 45% moisture depletion increases seed yield by 42.32%, compared to irrigation after 85% moisture depletion. Interaction of drought stress and potassium has had a significant effect on number of branches per plant, 1000-seed weight, leaf chlorophyll index, soluble carbohydrate content, and seed oil percentage, with the highest amount observed after 45% water drainage and application of 225 kg K ha-1.

In order to investigate the effects of integrated management of chemical and biological fertilizers on physiological traits, and grain yield of black cumin (Nigella sativa L.) under different irrigation levels, a split-plot experiment has been conducted based on a randomized complete block design with four replications at research farm University of Kurdistan in the spring of 2016. Two irrigation levels (irrigation at 100% and 70% of the plant water requirement) are randomized on the main plot. Five fertilizer levels (including 100% chemical fertilizers, 80% chemical fertilizers + biofertilizers, 60% chemical fertilizers + biofertilizers, 40% chemical fertilizers + biofertilizers, and non-fertilizer application) are randomized on a sub-plot. The results reveal that under irrigation at 70% of the plant water requirement conditions, proline concentration, soluble carbohydrates concentration, and lipid peroxidation have increased, while the values of other studied physiological parameters as well the grain yield have dropped. The combination of biological and chemical fertilizers positively affect the studied physiological traits and grain yield, such that the highest grain yield belongs to the combined treatment of 60% chemical fertilizers + biofertilizers (798.18 kg ha-1), showing an increase of 37.22% compared to the control (without fertilizer). Due to the positive effects of combining bio-chemical fertilizers on physiological parameters and grain yield, it is recommended to replace the combination of bio-chemical fertilizers instead of employing only chemical fertilizers.

Despite the progress of the livestock industry in Iran, the production of forage plants commensurate with this development has not been considered. Therefore, this study has been conducted during 2017, with the need to produce feed for livestock and poultry and with the aim of determining the best density and planting date on quantitative and qualitative characteristics of Guar forage. Taking place in the Rasht Rice research Institute-station located in the Village of GilPordehsar in the Sangar city, it evaluates four planting date (May 12, May 26, June 9, and June 23) and three plant densities (200, 400 and 600 plant.ha-1) factorially in a randomized complete block design with three replications. Results show that the planting date of May 26 and the density of 600 plant.ha-1 in terms of fresh forage yield (35.02 t/ha), crude protein (19.02%), dry matter (54.35%), and carbohydrate (26.12%) are superior to other planting dates and plant density under test. The highest yield of dry forage (6.1 t/ha) and neutral detergent fiber (58.23%) has been observed on May 12 and a density of 600 plant.ha-1. The amount of crude fiber has increased with delay in planting, but the percentage of Ash is not affected by different planting dates and densities. According to the results, in order to obtain the highest quantity and quality of forage in Guilan Province, the planting date of May 26 and the density of 600 plant.ha-1 is recommended.

Dust creates fine particulate matter and industrial and urban pollutants including factories of cement, gypsum, stone crasher, flour, daily winnowing of grain storage silos, heavy and light machinery traffic on dirt roads, car smoke and burning oil derivatives, power plants, etc. The dust damages the plants in various forms. The first damage the photosynthetic system by entering through the pores, and then by deposition on the leaf surface, reducing the light reached to the leaf, reducing the amount of photosynthetic pigments, changing the leaf temperature, and reducing the quantum yield, reducing the assimilation and closing stomata, exacerbated fungal and bacterial activity, pests and diseases, and ultimately reduce growth and yield. The amount of damage to the plant depends on the type of plant, cultivar, leaf area characteristics, the growth stage of the dust on the leaf surface, the type of dust and wind speed, the amount of dust thickness on the leaf, and the irrigation regime. Accordingly, the simulation of the effect of dust deposition and the reduction of light intensity due to it and their interactions on the growth and yield of chickpea cultivar Bivanich was performed as the dominant cultivar in the region. 

This experiment was carried out to investigate the effect of dust and light intensity on yield and some physiological and agronomic characteristics of chickpea cv. Bivanich, at the Research Field, Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran in 2016-2017. Experiment was Factorial based on randomized complete block design with three replications. Factors included light intensity (100, 75, 50, 25 and 0% light intensity) and dust deposition at flowering onset and no dust deposition. Sowing date was in late March 2016 in dryland with 25 cm line spacing and 13.5 cm inter-plant spacing in 6 lines with 3 m plots long. Shading was applied with plastic wrap fasteners that were 1 cm wide. The amount of chlorophylls a, b, total and carotenoides and soluble carbohydrates were investigated in mid grain filling. Yield traits and components of grain yield were studied at physiological maturity. The water requirement and water use efficiency were calculated for both total dry matter and grain yield. The data were analyzed by SAS software and the means were compared with LSD at 5% probability level. 

The results showed that from flowering stage, the interaction effects of dust deposition and different light intensities were significant on yield traits such as biomass yield, grain yield and number of seeds per plant. Both biomass and grain yields at 100 and 75% light intensities were not significantly different in non-dust treatments, but the number of seeds per plant decreased at 75% light intensity compared to 100%. In dust conditions, there was a significant difference between the light intensities of 75% and 100%, which was reduced significantly. This indicates that the deposition of the dust by increasing stress on the plant increased the sensitivity of chickpea to the amount of light intensity. In this experiment, the number of grains per plant was ranged between 13.6 to 16.9 for the light intensity levels and 9.3 and 14.3 between the dust conditions. The effects of dust deposition on the 100-grain weight were not significant but were significant due to light intensities and the light intensity of 0% decreased maximum of 8.4%. The effects of two treatments on photosynthetic pigments and soluble carbohydrates were significant. In general, the dust deposition reduced the amount of photosynthetic pigments and soluble carbohydrates. With decreasing light intensities decreased chlorophyll a and carotenoids, but increased chlorophyll b and total chlorophyll. Water requirement and water use efficiency were also affected by treatments. 

In general, the results showed that the deposition of dust from flowering stage caused damage to biomass yield, grain yield, grain number per plant, 100 seed weight, photosynthetic pigments and water use efficiency. Rate of this damage for biomass yield was 24.4%, grain yield 16.8%, grain number per plant 15.4%, chlorophyll a 13.5%, chlorophyll b 21.7%, carotenoids 10.7%, soluble carbohydrates 18.8% Water use efficiency was 24.6%. By reducing the light intensity up to 75% were not significantly decreased in no-dust conditions (control treatment), total dry matter yield, grain yield and grain number per plant. Effect of light intensity reduction from 50% (at no dust treatment) until 0% (without direct light) reduced the most important traits such as biomass yield, grain yield and grain number per plant, but in dust treatment with decrease in light intensity from 100% decreased significant. Both the deposition of dust and the reduction in light intensity had severe effects on the water use efficiency of chickpea. Accordingly, the ranges of changes were for water use efficiency between 0.61 and 1.23 (based on total dry matter).

In order to investigate the effects of water deficit stress and nano-TiO2 and salicylic acid foliar application on some biochemical traits of corn704 single crossplant, an experiment was conducted in split plot factorial based on RCBD in three replications at the Research Station of the Islamic Azad University, Tabriz Branch, during growing seasons of 2017-2018. Treatments were water deficit stress in three levels contained: 50, 75 and 100% filed capacity (FC) as well as thefactorial combination of nano-TiO2 (n-TiO2) foliar application in three levels contains: non application (control), 0.01 and 0.03 and salicylic acid (SA) foliar application in two levels contain: non application and 0.5%. Result showed that 0.5% SA foliar application under 50% water deficit stress had the highest peroxidase, polyphenol oxidase and lowest malondialdehyde activity. Furthmore, 0.01% n-TiO2 foliar application had the highest effect on peroxidase and lowest effect on malondialdehyde activity. Use and non-use condition of SA, 0.01% n-TiO2 foliar application had the positive effect on polyphenol oxidase activity. Foliar application of 0.01% n-TiO2 and0.5% SA under water deficit stress had the highest effect on soluble carbohydrates and proline. Based on the results, the guaiacol peroxidase enzyme activity increased with increasing water deficit stress level, so that the most activity of this enzyme was observed in irrigation with 50 % filed capacity. Considering the role of the traits studied in cooperation with each other in preventing the production of active oxygen species and reducing the effects of water deficit stress, SA and n-TiO2, increasing the activity of enzyme peroxidase, polyphenol oxidase, soluble carbohydrates, Proline and in contrast to the reduction of malondialdehyde reduced the negative effects of water deficit stress. Since SA and n-TiO2 had positive effects on the enzymes affecting plant physiology, the seed yield increased significantly compared to control and water deficiet conditions.

IntroductionOsmotic adjustment in plants can be achieved by the accumulation of compatible solution or metabolites. These compounds are known as compatible metabolites that accumulate naturally in tolerant plants due to non-interference in the normal metabolic response of plants to adapt or supplement. Proline, soluble sugars and other metabolites accumulation that are involved in osmotic adjustment have been reported for various plants. Different studies show that water absorption in sorghum plant, is due to osmotic adjustment and appropriate and fairly extensive root system. Moreover, there are some differences from genotype to genotype regarding the osmolites accumulation under drought stress conditions. Thus, the aim of this study was to investigate the effects of drought in the vegetative and reproductive growth stages on yield, its components and biochemical traits in grain sorghum genotypes.
Materials and MethodsIn order to evaluate the effect of water stress on grain yield and its components and some biochemical traits in grain sorghum genotypes (Sorghum bicolor L.), a field experiment as a split plot design was carried out with 3 replications in 2014 at the research farm of the southern Khorasan Agriculture and natural resources research and education center. Water stress treatments including normal irrigation (control), irrigation cut off in vegetative growth stage (emergence of terminal leaf as rolled) and irrigation cut off in generative growth stage (50% of plants in start of flowering) as the main plot and 10 genotypes of sorghum including KGS29, MGS2, Sepideh, KGFS27, MGS5, KGFS5, KGFS17, KGFS13 and KGFS30 were considered as sub plots. Each plot consists of 4 rows with a length of 6 m and row spacing of 60 cm, between plants on row was 10 cm. In addition, between each plot and the adjacent plot a row was considered to side effect reduction. To determine the yield components of each plot, half a meter in length was harvested and the number of plants, the number of panicles, grain yield, 1000 grains weight and the number of seeds per panicle were determined. To determine the yield, after removal of 2 marginal lines and a half meter of the beginning and the end of each plot, plants were harvested from the surface of 3 m2. Biochemical parameters including chlorophyll a, chlorophyll b, carotenoids, proline and carbohydrates were measured on the flag leaf after flowering stage in each plot. Flag leaves immediately wrapped in aluminum foil and transferred into liquid nitrogen tanks after separating from the plant. The samples were transferred to a freezer at -20 ° C to be measured traits on them. Measurement of the biochemical characteristics, such as chlorophyll a content, chlorophyll b, total chlorophyll a and b and carotenoid content was done according to Arnon method. Measuring the concentration of soluble carbohydrates was performed using sulfuric acid method. Measurement of free proline was done by Bates method. Sugar percentage of stem (Brix) was read by a refractometer after cutting and placement of juice out of it.
Results and DiscussionResults showed that water stress had a significant effect on grain yield, 1000 grain weight, the numbers of seed per panicle and caused to decrement of them. The performances of different genotypes varied significantly for all traits, indicating high variability among them. In case of 1000 seed weight, the interaction between water stress and genotype did not show a significant difference, however, other traits which mentioned above showed a significant difference in this aspect. Regarding the biochemical characteristics, the impact of drought in the vegetative and reproductive growth stages was different, as drought reduced the content of chlorophyll and carotenoid and increased the content of soluble sugar and free proline and stalk sugar content (Brix). In term of grain yield, genotype KGFS13 with the average yield of 5060 Kg per hectare and then genotype KGFS17 had the highest yield. Comparison of interaction between genotype and stress about carbohydrate (sugar solution) concentration of leaves indicated that genotype KGFS30 in severe drought stress, had highest level and genotype KGFS27 in normal irrigation and genotype KGS33 in medium drought stress condition commonly had the lowest carbohydrate content of leaves respectively.
ConclusionsOverall results indicate that proline and soluble carbohydrates and stem sugar content increased under drought stress and photosynthetic pigments are reduced.

IntroductionThis study was aimed to study effects of different bacterial strains on proline, chlorophyll and carbohydrate content under water shortage conditions in the field.
Materials and methodsA split plot experiment was used based on a randomized complete design in three replicates, with stress in three levels of 40, 80 and 120 mm evaporation from pan and nine different bacterial strains as the main factor and the sub-factor, respectively.
Results and DiscussionThe results showed that application of different bacterial strains and stress influenced the quantity of soluble carbohydrate in the leaves and proline. The highest amount of carbohydrate was obtained from seed inoculation of pseudomonas 169 along with 120 mm evaporation from the pan. Highest antioxidan properties by 89 mg/ml obtained in Azospirillium off and irrigation after 120 mm evaporation from the pan and lowest observed by 15.3 mg/ml in no bacterial treatment and irrigation after 40 mm evaporation from the pan. Also highest essential oil yield by 4 gr observed in herbasilus and 120 mm evaporation from the pan and lowest observed in Pseudomonas 168 and 40 mm evaporation from the pan by 0.85 gr. In this investigation in low and high grought stress using bacterial strains increased prolin and carbohydrate production than control. So using azeto 5 and azospirillium 21 in moderate drought and azeto 5 and herbasillus in sever drought stress can increase essential oil yield. These results provide enough evidence as to application of biological fertilizers brings about enhancements to the quality and quantity of dill. This could increase the plant oil yield under water shortage is and moderate conditions compared to the control.
ConclusionsThe use of appropriate strains of bacteria such as Azatobacter5 and Azospirllium 21 can in condition of moderate and Azatobacter 5, pseudomonas 169 under stress condition, in medicinal plant to increase oil production.

Drought stress is one of the major causes of reduction in crop production. Study physiological and biochemical processes related to drought stress can give better insight about mechanism of drought tolerance. To study the physiological and biochemical processes, three genotypes including K-S-31167, GE-288 and Naz were subjected to 3 level of drought stress based on 25, 50 and 100 percent of field capacity using CRD design with three replication using Factorial arrengment, Droght stress was applied five weeks after planting and lasted for 10 days. Second terifoliate were used for sampling. The results indicated significant changes in the electrolyte leakage (EL), prolin content (PC) and carbohydrates content (CC). Tolerant genotype (K-S-31167) had greater PC but lesser EL compare to relatively tolerant genotype (GE-288) and sensitive genotype (Naz). This indicates that tolerant genotype had higher membrane stability during stress. Results from measurement of soluble carbohydrate and expression of sucrose synthase and vacuolar invertase genes showed increase and decrease in the expression of these genes resulted in increase and decrease in the activity of the invertase and sucrose synthase enzyme which in turn influences the concentration of soluble materials which acts as metabolic signal in response to stress.

Cold stress is one of the limiting factors in production of greenhouse vegetables. Chemicals offer useful approach to reduce low temperature-induced damages. This study was conducted to evaluate the effect of foliar application of methyl jasmonate (MeJA) at concentrations of 0 (control)، 50، 100، 200 µM) on electrolyte leakage (EL)، relative water content (RWC)، soluble carbohydrates، proline، chlorophyll content and chilling index of greenhouse- grown cucumber (Cucumis sativus L. cv ‘Negin’) in 4-6 leaf stage. MeJA was sprayed two times/day on cucumber seedling in a greenhouse of Bu-Ali Sina University، as a factorial based on completely randomized design with five replications per treatment، inlate- summer of 2013. Two days after spraying، seedlings were transferred from 25ºC to cold chamber and were subjected to chilling treatments of 15، 10 and 5 ºC for 4 hours. The EL of all plants increased with reducing the temperature. However، in MeJA-treated plants، especially in application of 200 µM، a lower leaf EL was observed. A clear increase in soluble carbohydrates and proline concentration was observed with decreasing temperature from 15 to 5ºC in all plants while in MeJA -treated seedlings، especially in application of 200 and 100µM، a greater amount of these osmolytes were observed in compared to control. Moreover، exogenous application of MeJA reduced RWC and visual damage of cold-stressed seedlings but increased chlorophyll content in compared to control plants. These changes correlated with the increment of cold tolerance in the cucumber plants. The results indicated that MeJA application especially at 200 µM، has the capacity to improve chilling tolerance of seedlings and can be used as a prophylactic tool to protect against chilling injury of cucumber cultivars in greenhouses

This study was designed to evaluate the effects of post anthesis moisture stress on agronomy traits، storage of stem water soluble sugars and dry matter remobilization of wheat. The pot experiment was laid out in a randomized complete block design (RCBD) in a factorial arrangement with three replications in Campus of Agriculture and Natural Resources، Razi University in Kermanshah state in the west of Iran during the growing season from 2011 to 2012. In the experiment، moisture stress was applied at grain growth stage (soil moisture was around 30% of field capacity from the anthesis stage to the maturity - 65 to 99 Zadoks scale) and different wheat varieties (such as Pishtaz، DN-11، Sivand and Marvdasht) were evaluated as the second factor. The results show that، water stress application at grain growth stages significantly decreased grain yield by decreasing of grain weight. Under application of water stress at grain growth stage، Marvdast and DN-11 cultivars had the lowest grain yield. The occurrence of water stress in experiment، significantly decreased stem dry mater and remobilization. In contrast to this results، in water stress condition stem soluble sugars concentration significantly increased. In water stress conditions، the amount of dry matter remobilization from stem lower internodes (internodes below penultimate) to grain، its efficiency and contribution of its in grain yield increased by 11%، 32% and 121%، respectively. Also، penultimate and stem lower internodes had the highest water soluble sugars concentration under water stress. Water deficiency stress could not increase the remobilization efficiency but in terms of mentioned traits، there were significant differences between cultivars. So، indicated that these traits can be used for identifying drought tolerant high yielding genotypes in winter wheat breeding programs.

Soil and water salinity is a major constraint in arid and semi-arid regions. In order to study the impact of water salinity on physiological characteristics and dry matter production of six linseed genotypes، a 4-replicate factorial randomized complete block pot experiment was conducted. Salinity consisted of four levels: 0 (control)، 35 (low salinity)، 70 (intermediate salinity) and 105 mM (severe salinity) of NaCl and genotypes consisted of C1، C2، C3، B، 33 and Khorasan. Severe salinity led to 37، 33، 36، 3، and 61% decreases in chlorophyll a (chl a)، chl b، chl total، chl a/chl b and carotenoids contents، respectively. Mean proline content of plant leaf and root increased by 6. 35- and 1. 54-fold under 105 mM، compared to the control، respectively. Genotypes C3 and 33 indicated the greatest (6. 4-fold) and smallest (2. 8-fold) increases in leaf proline content، respectively. Khorasan indicated the greatest increases (3. 81-fold) and C3 the smallest (1. 97-fold) increase in leaf soluble carbohydrate content. While mean antioxidant activities increased with salinity، the greatest mean enzymes activities were detected with the intermediate level of salinity. In contrast to the rest of genotypes، Khorasan and 33 indicated increases in their catalase، ascorbate peroxidase and glutation peroxidase activities when subjected to the severe salinity، compared to the intermediate salinity. Mean plant dry mass decreased with increase in salinity، with Khorasan indicating the smallest decrease. It could be concluded that physiological attributes، growth and dry mass production in linseed is negatively affected by NaCl، even with intermediate water salinity. Genotypes Khorasan and C3 seemed to be more resistant to the NaCl salinity due، at least in part، to maintaining or increasing the level of antioxidants activity.

Investigation of physiological responses to water deficit in sesame (Sesamum indicum L.) genotypes can help to identify effective mechanisms of plant resistance to stress. Therefore, chlorophyll content, proline, soluble carbohydrates, net photosynthesis rate, stomatal conductance, maximum quantum efficiency (fv/fm), plant height and shoot dry weight in a complete block factorial pot experiment with three replications were conducted at the College of Agriculture, Isfahan University of Technology, Isfahan, Iran. Four levels of irrigation included irrigation when the soil, water potential of pots was approximately -0.2 MPa (control) =W1, -0.5 MPa (low water deficit) =W2, -1.0 MPa (intermediate water deficit) =W, and -1.4 MPa (severe water deficit) =W4 and 12 sesame genotypes. The highest reduction in chlorophyll content (46%) in the severe water deficit and the genotype was Non-branching Naz. Net photosynthesis rate, stomatal conductance, total chlorophyll content and maximum quantum efficiency (Fv/Fm) were decreased by 43.8%, 39.6%, 46.6% and 17.7%, respectively, compared to control. Proline and soluble carbohydrate content of sesame genotypes was increased by 129.8% and 35.6%, respectively, under severe water deficit compared to control. Plant height and plant dry weight decreased with severe water deficit by 21.5% and 52%, respectively, due to severe water deficit. Severe water deficit, with negative effects on photosynthetic systems by limiting stomatal conductance and reduce the net photosynthesis rate, was due to the decrease in maximum quantum efficiency. Decrease in maximum quantum efficiency on one side and the chlorophyll content reduction in other side, reduces the photosynthetic production and reduce the yield (dry matter) per genotypes.

Studying the physiological responses of linseed genotypes to water deficit stress may be helpful in recognizing the linseed resistance mechanisms to the latter stress factors. Therefore, a split plot RCBD field experiment was conducted with three replications to explain interrelations of leaf chlorophyll, proline and soluble carbohydrates content and grain yield of six linseed genotypes under three irrigation regimes. Three levels of irrigation: 70 (no stress), 115 (moderate stress) and 145 mm (severe stress) evaporation from a Class-A Pan served as the main plots and six linseed genotypes consisting of C1, C2, C3, B, Khorasan and 33 were considered as sub plots. Water deficit led to significant decreases in grain yield and chlorophyll content, but it led to increases in proline and soluble carbohydrates content of linseed leaves. Genotype B produced the highest grain yield (2193 kg ha), genotype C1 the greatest decrease (34%) in chlorophyll content and genotype B the highest increase (93%) in soluble carbohydrate content under severe stress. C1, C2, C3 and Khorasan indicated the greatest and B and 33 genotypes the smallest increases in proline content under sever water deficit stress. At least with present set of conditions, increasing soluble carbohydrates played a more significant role, compared to proline and chlorophyll content, in tolerance to moisture deficit stress.