جستجوی مقالات مرتبط با کلیدواژه "plant growth regulator" در نشریات گروه "زراعت"

The present study was performed to study the effects of MS, WPM, B5 culture media and benzylaminopurine (BAP) hormone on hyssop proliferation, and to assess the effects of different concentrations of IBA and IAA hormones on rooting characteristics of hyssop.

The experiments were conducted as a factorial with a completely randomized design with three replications at the laboratory of tissue culture of the Faculty of Agriculture, University of Jiroft. To produce sterile seedlings, seeds were collected from mountainous regions of Kerman province and planted on the MS medium. The single-node explants were cultivated on MS, WPM, and B5 culture media containing the benzylaminopurine hormone with concentrations of 0, 1, and 2 mg/L. To induce rooting, the shoots were placed on the MS culture medium containing 0.5 and 1 mg/L of indole butyric acid and indole acetic acid. GiaRoots software was employed to analyze the architecture of the roots obtained.

Based on the research results, the highest proliferation coefficient was obtained in the MS culture medium with a concentration of 2 mg/L of benzylaminopurine hormone. In addition, the results of root architecture analysis showed that IBA hormone with a concentration of 1 mg/L demonstrated the most effective treatment for rooting induction.

The adaptation test results demonstrated that 85% of the plants transferred to the greenhouse survived.

With the aim of evaluating the effects of salicylic acid and brassinosteroid application on some physiological traits and arsenic accumulation in spinach under arsenic stress conditions, an experiment was conducted in a factorial experiment in the form of a randomized complete block design with four replications in the year 2022 in the Nutrition Research Center, Department of Food Hygiene and Quality Control, School of Nutrition and Food Sciences, Shiraz University of Medical Sciences, Iran. The experimental factors included salicylic acid (0, 0.5, and 0.75 mM), brassinosteroid (0, 0.5, and 0.75 µM), and arsenic stress (0, 50, and 100 µM). Arsenic stress, especially at 100 µM, reduced the net photosynthetic rate, transpiration rate, stomatal conductance of spinach leaves and biomass. Arsenic stress increased the concentration of malondialdehyde, hydrogen peroxide, osmolytes, as well as antioxidant enzymes activities in spinach plants. Application of brassinosteroid and salicylic acid significantly increased activities of antioxidant enzymes (peroxidase, ascorbate peroxidase, and superoxide dismutase), osmolytes accumulation (carbohydrates and proline) and spinach biomass; in contrast, application of brassinosteroid and salicylic acid decreased the concentration of malondialdehyde and hydrogen peroxide in spinach plants under arsenic stress conditions. Arsenic accumulation was higher in spinach roots than in leaves. Under 100 µM arsenic stress, the application of different concentrations of salicylic acid and brassinosteroid, individually and in combination, significantly reduced arsenic accumulation in spinach, with the highest positive effect being observed in the treatment of 0.75 mM salicylic acid + 0.75 µM brassinosteroid. In conclusion, brassinosteroid and salicylic acid application increased the tolerance of spinach plants against arsenic stress by improving gas exchange, activity of antioxidant enzymes, accumulation of osmolytes, stability of the membranes, and as a result plant biomass; the positive effects of brassinosteroid and salicylic acid together were greater than that of brassinosteroid or salicylic acid applied separately.

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.

The use of seed priming technology to accelerate the germination and seedling emergence of multi-purpose plants such as halophytes (Alhagi) with the ability to produce medicine and forage under environmental stress conditions or use of saline water (such as seawater of Persian Gulf) has received much attention today. Therefore, the present study was conducted to investigate seed priming methods and different salinity levels on germination, seedling emergence, and some growth responses of Alhagi plant.

Two separate split-factorial experiments were conducted based on a randomized complete block design with four replications as a petri dish culture (first experiment) and a pot experiment in the field was performed in the Department of Plant Production and Genetics, Faculty of Agriculture, Shahid Chamran University (Ahwaz, Iran) during 2020-21. In both experiments, different levels of salinity (municipal water source with EC=0.96 dS.m-1, 8 and 16 dS.m-1 using seawater of Persian Gulf) were assigned as the main plot, and different methods of seed priming (non-priming, hydro priming, hormonal priming with 50 ppm gibberellin and hydro priming+hormonal priming with 50 ppm gibberellin) and species (A. maurorum and A. graecorum) were assigned as sub-factors.

The results showed the significance of salinity × species × priming interaction on all studied traits. According to the mean comparison results, the highest values of germination percentage, seed vigor index, seedling emergence, plant height, number of branches, total dry matter and stomatal conductance were obtained from a municipal water source with EC=0.96 dS.m-1 and hydro priming+hormonal priming with 50 ppm gibberellin for A. graecorum (29.1, 90.2, 24.0, 32.3, 52.5, 52.1 and 32.4% increase compared to non-priming and control salinity stress on this species, respectively). The output of the fitted logistic model to seedling emergence percentage showed that this model well explained the relationship between seedling emergence of two Alhagi species in responses to salinity and seed priming (R2 adj≥0.98 and RMSE≤3.38). Therefore, in both studied species, the decline in seedling emergence started from the 8 dS/m salinity level. However, at the 16 dS/m salinity level, the slope of increase in seedling emergence percentage was slower per time unit.

To cultivate and exploit the saline coastal lands and also to restore the pastures in the country, A. graecorum species under the combined treatment of hydro priming + hormonal priming with 50 ppm gibberellin are recommended in comparison with other treatment levels.

Highlights:

1- Germination and growth responses of two Iranian Alhagi species and the possibility of production by irrigation of seawater of Persian Gulf were investigated.
2- Seed priming technique was used to accelerate seedling emergence and improve some traits in two Alhagi species.

Wheat is a major staple food crop in the world. Although all abiotic stresses adversely affect the wheat growth and production, water scarcity imposes the most severe effects on this crop. Drought stress is also believed to affect the uptake, transport and accumulation of key inorganic nutrients in plants. Silicon occurs abundantly in soils, but in the field of plant growth the other inorganic elements for plant growth are more important than Silicon. However, Silicon plays an effective role in plants under stressful conditions. Silicon entails useful effects in plants under water-deficit treatments, with respect to drought-induced regulation of metabolic processes and water relations. Of several plant growth regulators, Cycocel (CCC) is believed to be very effective in masking the adverse effects of different abiotic and biotic stresses on crops as well as being an essential component of the signal-transduction pathways operating in plants exposed to environmental cues including drought stress. Exogenously applied CCC is believed to affect absorption and transport of nutrients, stomata regulation, growth and photosynthetic rate, chlorophyll synthesis and transpiration. The literature has little information on the role of Silicon and CCC applied in combination in alleviating drought-induced injurious effects on plants. Therefore, in the present study, we appraised the effects of exogenous Silicon and CCC applied individually or in combination on wheat growth and grain yield under water-deficit conditions.

This study was carried out in Tiran province, Isfahan, Iran during 2018-2019, as a split-split plot design in randomized complete block with three replications. The main plots considered irrigation regimes (full irrigation and 40% field capacity irrigated), sub-plots considered Silicon and cycocel application (control, 3.6 g l-1 Silicon, 210 mg l-1 Cycocel, and 3.6 g l-1 Silicon + 210 mg l-1 Cycocel) and sub-sub plots considered two wheat cultivar (Sirvan and Chamran). All measurements based on fresh plant samples were done before the grain-filling stage. Measurements included relative water content, soluble sugars and soluble proteins; activities of peroxidase, ascorbate peroxidase, catalase, superoxide dismutase, levels of hydrogen peroxide, malondialdehyde, concentrations of Ca, K and Mg and leaf water potential. At maturity, yield and yield components were measured. Statistical analysis of data was performed using the MINITAB statistical software.

Drought stress caused a considerable reduction in yield and yield components and relative water content of both cultivars. Application of Silicon and cycocel effectively improved these parameters in water-deficit treatments. Moreover, water-limited conditions markedly promoted the activities of key antioxidant enzymes including peroxidase, ascorbate peroxidase, catalase and superoxide dismutase, while enhancing the accumulation of soluble sugars, potassium, magnesium and calcium in leaf tissues. Application of Silicon and cycocel further enhanced the activities of the key antioxidant enzymes and accumulation of osmolytes, and decreased the levels of H2O2 and malondialdehyde in drought stressed plants. Synergistic effects of Silicon + cycocel application on yield and physiological parameters were apparent compared with Silicon or cycocel applied separately. Water-stress alleviation and yield improvement in the wheat cultivars by Silicon and cycocel application was attributable to partly improved osmotic adjustment and antioxidant activity as well as to more favorable water status under stress conditions.

Foliar application of Silicon, CCC and especially the combination Silicon + CCC, markedly improved grain yield and yield components of the two wheat cultivars under water-deficit. In Silicon, CCC and Silicon + CCC treatments, grain yield was 15.63%, 16.60% and 24.32% higher respectively, than with no foliar application under water stress in cv. Chamran, and 10.25%, 16.02% and 19.25% higher in cv. Sirvan. The results of the study highlight the role of Silicon and CCC application in regulating water-stress response of wheat, suggesting that Silicon and CCC are involved in physiological activities. These results showed positive effects of Silicon and CCC in terms of increased antioxidant activity as well as relative water content and leaf water potential. In addition, Silicon and CCC stimulated the active accumulation of some osmolytes in leaves of water-stressed wheat plants, which suggests enhanced osmoregulation ability. The synergistic effects of Silicon + CCC application on yield and physiological parameters were greater than of Silicon or CCC applied separately. Therefore, proper application of Silicon and CCC might result in increased production of wheat, particularly in dryland areas.

In order to evaluate the effect of seed priming of Quinoa (Chenopodium quinoa Willd) on Seedling growth and germination Indexes of two varieties of Quinoa (Titicaca-Giza 1), studies in the form of a factorial experiment in a randomized complete block design (RCBD) with two factors four repetitions were conducted of Seed Technology Laboratory Shahed University in 2020. The experiment was the first factor included control ((no priming), Hydropriming, Potassium nitrate (0.02% w / v), Salicylic acid (0.6 mM), Calcium chloride (at 20 and 40 mM) and two genotypes of quinoa (TiticacaGiza 1). The best priming level for 40 mM calcium chloride was in both genotypes. Results of experiment showed that effect of priming on seed percentage at the level of one percent was significant but their interaction priming, genotyping on seed percentage not significant. Also, effect of priming, genotyping and their interaction on normal seedling percentage, seedling length, allometric coefficient and seed vigor length index, at the level of one percent was significant. Results showed that the highest seed percentage obtained in for level 20 (100 %) and 40 (100 %) mM calcium chloride priming in both genotypes (Titicaca-Giza 1). Generally, priming of 40 mM calcium chloride to highest germination indexes and of Titicaca and Giza1 genotype was recommended.

Cadmium contamination has decreased crops quality and quantity due to its uptake by plants and inhibition of its proper growth. Plants of Brassicacea family like black mustard have a high growth capacity in heavy metals polluted conditions. Some rhizobacteria can help to the movements of heavy metals in the soil. Plant growth regulators also have an important role in the induction of plant reactions to most of abiotic stresses such as heavy metals. The aim of this experiment was the evaluation of effect of growth promoting rhizobacteria, salicylic acid and brassinosteroid on reduction of cadmium stress effects in black mustard.

In order to study the effects of growth promoting rhizobacteria and plant growth regulators on physiological properties of black mustard under cadmium stress conditions, a factorial experiment was conducted based on randomized complete block design with four replications at research greenhouse of Mohaghegh Ardabili university. Experimental treatments included two cadmium levels (0 and 100 milligrams per kilograms of soil), three levels of rhizobacteria (control, Azospirillum, Pseudomonas) and three levels of growth regulators (control, Salicylic acid, Brasinosteroid). Before planting the seeds were inoculated with rhizobacteria and also growth regulators were sprayed in two stages during growth period on plants. After harvest some traits including MDA, proline, soluble sugars, photosynthetic pigments, membrane stability index and secondary metabolites were measured.

Results of means comparisons indicated that cadmium application by some effects including oxidative stress induction, increased MDA, proline, soluble sugars, phenol and flavonoid contents of leaves and decreased chlorophyll a and b, carotenoids and anthocyanin contents, membrane stability index and plant yield. Malondialdehyde and proline contents were reduced significantly by rhizobacteria inoculation and growth regulators application and phenol and flavonoid contents as well as plant yield were enhanced in both cadmium levels by rhizobacteria. Whereas growth regulators spray increased chlorophylls a and b contents, soluble sugars, membrane stability index, phenol, flavonoid, anthocyanin and plant yield and also the rhizobacteria enhanced soluble sugars, anthocyanin content and membrane stability index significantly. In addition, there was no significant difference between salicylic acid and brassinosteroid in all traits and pseudomonas inoculation compared to azospirillum indicated a significant superiority regarding some traits including membrane stability index and plant yield.

It can be concluded that cadmium contamination via the oxidative stress induction leaded to cell membrane destruction and increasing malondialdehyde content and also it resulted decreasing chlorophyll content of plant that is associated with increasing proline synthesis under stress condition. As a result of cadmium contamination stress, the activity of carbohydrates synthesis enzymes was increased and resulted increasing soluble sugars content and consequently increasing secondary metabolites content. By the application of rhizobacteria and plant growth regulators, the effects of oxidative stress were decreased and it leaded to enhancing membrane stability and reducing malondialdehyde content. Additionally, these treatments increased chlorophyll production and decreased proline content. By increasing chlorophyll content affected by these treatments, soluble sugars production in plants was increased and it resulted increasing secondary metabolites production in plant. Considering these results, the application of growth regulators and growth promoting rhizobacteria in order to decrease cadmium stress effects on black mustard grown in contaminated soils is recommended.

Red flesh apple belongs to Malus niedzwetzkyana of Rosaceae family. It has high levels of important phytochemicals like antioxidants, flavonoids and anthocyanins in its cortex, which, in addition to attractiveness, is a source of benefit compound. The aim of the present investigation was to optimize efficient protocols for micro propagation of red flesh apple in order to use the results in future breeding strategies.

During the early spring, stem cuttings of growing red flesh apple trees were surface-sterilized in 70% ethanol and 50% sodium hypochlorite. Then, sterilized samples were placed in the test tubes containing MS medium supplemented with 2 µM BAP. At the proliferation stage, interactive effects of BAP (0, 2, 4, 6 mM) and GA3 (0, 3, 6 mM) on various aspects of proliferation (multiplication rate and vegetative growth characteristics such as number of produced shoots per explant, shoots length, leaf numbers, and the fresh and dry weight of explants) were investigated. At rooting stage, the effect of different concentrations of IBA or NAA (0, 1, 2, 3,4 µM) on the percentage of rooting, number of roots per explant and length of roots were compared. At acclimatization stage, the plantlets were transferred into pots with a volume of 200 ml containing sterile compound at the greenhouse condition.

The results showed that there was a significant difference between the effects of various concentrations of BAP and GA3 on micro propagation of red flesh apple. The best result in proliferation (7.9 of axillary shoots after 8 months) was obtained from explants that were cultured in the medium containing 4 mM BAP and 3 mM GA3. At rooting stage, the maximum rooting percentage (85.2%) was obtained in the medium containing 3 mM IBA. In addition, rooted explants from IBA treatments were successfully acclimatized (100%) in the greenhouse, but rooted explants in NAA treatments were weak in acclimatized stage (40%).

Measuring the growth rate is the major economic parameter for successful plant production at in vitro conditions, which is usually characterized by the number of axillary shoots, number of regenerated leaves and increase in the length of shoots and fresh and dry weight. We obtained the highest growth rate of red flesh apple in the culture medium containing 4 μM of BAP. The efficiency of BAP as an important cytokinin in apple proliferation has been reported in other studies as well. The results of the present investigation showed that highest rooting percentage was obtained from culture medium containing 3 μM of IBA. In addition, morphology of roots varied in callus formation and longitudinal growth and the samples rooted in IBA treatments had stronger roots than the rooted samples in NAA treatments. It seems that exposure to NAA instead of IBA stimulates indirect organogenesis and produced undesirable side effects on roots, such as callus formation, which can cause plantlets weakness during the period of acclimatization.

This research was carried out to study the grain yield, yield components and NDVI (normalized difference vegetation index) responses of four wheat cultivars to growth retardant cycocel under terminal drought stress conditions. The experiment was laid out as a split split plot with three replicates at the experimental farm of the School of Agriculture, Shiraz University, Shiraz, Iran in 2016-2017 and 2017-2018 growing seasons. The treatments consisted of two levels of water stress (full irrigation and irrigation cut off at the beginning of flowering), exogenous cycocel in two levels (4 g ha-1 and 0) and four wheat cultivars (Sirvan, Baharan, Varedati and Ofogh). Water stress reduced the measured traits including, grain number per ear (19%), 1000-grain weight (14%), biological yield (22%), grain yield (29%), and NDVI (17%). Exogenously-applied cycocel compensated for some of such reductions including, number of spikes per square meter (18%), grain number per ear (29%), 1000-grain weight (6%), biological yield (11%), grain yield (17%), and NDVI (5%). Ofogh and Sirvan cultivars showed a better response for most of the measured traits to water stress conditions when cyclocel was used. Regarding the ameliorating role of cycocel in reducing negative impacts of terminal water stress, application of this growth regulator could be recommended for similar conditions.

Saffron is one of the most important crops and medicinal plants in Iran. The research was accomplished in order to investigate the effects of Benzyl aminopurine hormone treatment, application of bio-fertilizers (Phosphate Barvar2 and mycorrhiza) and maternal corm weight on the quantitative indices of saffron cormlets and flowers yield as a factorial based on randomized complete block design with three replications was conducted in Yasouj region. Experimental treatments consisted of large (7.1-10 g) and small (4-7 g) corms, priming with benzyl aminopurine at concentrations of 0, 250 and 500 mg/l and biofertilizer levels (no fertilizer, Mycorrhiza (Glomus mossea) and fertilizer, Phosphate Barvar2) were used. The results showed that all quantitative traits of saffron corm were significantly affected by hormonal priming and maternal corm weight (except for corm weight); But biofertilizer had only significant effect on corm number and flower dry weight. The Hormonal priming at a concentration of 250 mg/l increased the number and weight of corms by 30 and 27%, respectively, and the dry weight of stigma and filament by 26% compared to control. Also, all flower components and number of corms were significantly increased by using larger maternal corms than small corms. The use of bio-fertilizers as compared to no fertilizer increased 13 and 59% corm number and weight, respectively. Phosphorus and zinc content in corms increased only under the influence of mycorrhiza fertilizer application. Whereas, with the use of benzyl aminopurine and mycorrhiza fertilizer, the iron content increased twice as much as the control. Generally 250 mg/l application of benzyl aminopurine, bio-fertilizers and larger corms (7.1-10 g) it had a positive effect on most of the measured traits

Cadmium is one of the soil primary pollutants which is categorized as heavy metals and brassicaceae family are able to accumulate high amounts of heavy metals such as cadmium by producing high amounts of dry matter. In order to evaluate fatty acids variation, seed oil percentage, yield and yield components of black mustard as affected by growth promoting rhizobacteria and growth regulators under cadmium stress condition, a factorial experiment based on randomized complete block design was conducted at the Research Green House of Mohaghegh Ardabili University with four replications. Experimental treatments were two cadmium levels (0 and 100 milligrams per kilograms of soil), three rhizobacteria levels (control, Azospirillum and Pseudomonas) and three growth regulator levels (control, salicylic acid and brassinosteroid). Mean comparisons indicated that cadmium treatment decreased pods number per plant, grain number per pod, root dry weight, seed oil percentage, oleic, linoleic, eicosenoic and erucic acid percentages, significantly. Growth promoting rhizobacteria increased all of above mentioned parameters significantly, where as, it decreased palmitic acid content. Plant growth regulating sprays resulted in a significant increment in plant yield, shoot and root dry weight, seed oil percentage and all kinds of unsaturated fatty acids while it reduced stearic acid content and saturated fatty acids. The interaction of cadmium×rhizobacteria indicated that both cadmium levels used, along with rhizobacteria treatment, increased plant yield, thousand seed weight, shoot dry weight, linolenic acid and unsaturated fatty acids, where as decreased stearic and saturated fatty acids, significantly. In general, the effects of cadmium on these traits were different. Interaction of cadmium×growth regulators, spray application of growth regulators, under both cadmium levels, reduced palmitic acid and induced unsaturated fatty acids significantly and cadmium application had an inverse result.

Garlic has the second rank in Allium species in the case of highly used plant species after onion with high nutritional and medicinal values. Garlic is a vegetative product and is contaminated by many pathogens and viruses. Meristem culture is an in vitro bulblet production method for removing the viral diseases. The purpose of this study is to evaluate effect of growth regulators on micropropagation and bulblet formatiom in local clones of garlic in Hamedan province by meristem culture. This research was done as a factorial experiment in a completely randomized design with ten clones and four growth regulators including: MS, MS+1µM BA, MS+1µM BA+1µM NAA and MS+10µM BA+5µM NAA. After the first stage and plantlet production, a factorial experiment in a completely randomized design with 10 clones and 4 hormonal treatments was used in MS medium containing 6% sucrose with three replications. The cultured samples were placed in a refrigerator at a temperature of 4 ° C for four months and then transferred to the growth chamber with 25ºC temperature and photoperiod of 16/8 h (day/night). A month later, take notes of samples. In order to normalize the data logarithmic transformation and uniformity test of variances were used and then Data were analyzed by SAS software and the meanings were compared using Duncan's test. In the first experiment, the use of growth regulators in the culture medium causes significant changes in the production seedling growth characteristics. MS + 1μM BA medium produced the highest seedling weight and leaf length. Garlic clones significant difference in the number of leaves, leaf length and weight of seedling showed. Sheverin clone highest number of leaves, leaf length and the maximum weight the seedlings produced. Interaction between hormonal treatments in clones was not significant for any of the studied traits. In the second stage of the experiment, the interaction of clones in hormonal treatments was significant at 1% level for all traits (plantlet weight, Bulblet weight, Bulblet number, Root weight and Leaf weight). Sheverin clones in MS + 10μM BA + 5μM NAA were highest in all studied traits. totally, the results of this research showed that we can identify the responces of the top clones of the garlic province of Hamedan in meristem culture. Also we achieved the suitable concentration and combination of plant growth regulators on regeneration of different clone garlic in vitro conditions. As a result, a better protocoles were introduced for micropropagation and bulblet formatiom of the garlic in tissue culture.

Salicylic acid is one of the plant growth substances affecting growth and salinity tolerance in plants. In order to evaluate salicylic acid and salt stress effect on some morphological and physiological traits and antioxidant enzymes activity in Thymus daenensis Celak. the experiment was done using four levels of salicylic acid (0, 150, 300 and 450 ppm) and four levels of sodium chloride (0, 50, 100 and 150 mM), based on a completely randomized design in three replications. The results showed that different levels of salinity significantly increased proline content, carbohydrates concentrations, fresh weight and peroxidase and catalase enzyme activity and decreased the leaf area and protein concentration. Also the interaction results of salinity and salicylic acid treatment caused significant increase levels of proline, soluble sugars and protein concentration, ratio of root to stem, dry weight and increased catalase and peroxidase enzyme activity. Based on the results of these study, foliar spraying of salicylic acid by increasing the activity of antioxidant enzymes, proline and Soluble carbohydrates concentrations under salinity stress conditions, improved physiological traits of plants and enhanced plant resistance to salt.

IntroductionHormones are the most important crop plant growth regulators in response to genetic and environmental conditions. Paclobutrazol (PBZ) is a triazole plant growth regulators of the categories used in the early 1980s. According to some researchers, paclobutrazol reduced plant height (Yang et al., 2001), increasing the number of tillers per plant and increasing the number of grains per spike (Bayat et al., 2010), increased tolerance to environmental stresses and non-environmental (Berova et al., 2002). Heat stress is one of the major limiting factors of environmental in wheat production and wheat germ stage is the most sensitive periods of high temperatures (Pradhan et al., 2012). The aim of this study was to evaluate the physiological characteristics of wheat grain growth and yield than using different concentrations of paclobutrazol foliar application is in optimal conditions and heat stress.
Materials and MethodsThis study in two independent experiments were conducted each split plot in a randomized complete block design with four replications carried out in Dezful area, Iran in 2013-2014. The first experiments on the cultivation of crop varieties recommended (November) and in order to phenological stages of plant growth to coincide with heat stress after pollination season, planting dates in other experiments the first was in February. In each experiment, four levels of paclobutrazol (0, 50, 100 and 150 mg per liter) at the beginning of stem elongation sprayed on to Shoot applied, As main plots and three cultivars of wheat (Star, Vee/Nac and Chamran) were considered as sub plots.
Results and DiscussionThe results showed that in both optimum conditions and heat stress season, consumption growth regulator paclobutrazol significantly increased the effective grain filling period, 1000-grain weight and grain yield, but the effect of this treatment on the grain growth rate was not significant. Results of stepwise regression analysis showed that the duration of grain filling was the most important attribute of variations grain weight (R2=0.59) and then grain growth rate much of the rest of the changes are determined.
ConclusionsThe yield of the late Star because of the late Star pollination and subsequent exposure to heat stress than in the final stages of the early Vee/Nac and middle Chamran, the gradient of the effective grain filling period, grain weight and higher grain yield under heat stress end of the season was compared to optimum conditions. Overall results showed that the effect of growth regulator paclobutrazol on characteristics of grain growth and yield were positive, therefore can be with the proper use from the damage resulted from heat stress, especially at critical stages of plant growth can be prevented.

Plant growth regulators (PGPRs), refers to substances which in very small quantities could have huge impacts on plant growth and developments. These compounds might be natural or synthetic, and natural forms are called plant hormone. Some of these compounds have been known for decades and their structure, amount and plant responses also have been identified already, while many of them have been identified only in the recent years. Some PGPRs, due to direct impact on the growth, development and even the quality of crops, have many commercial applications and annually adding to number of consumers in some countries. However, many of them are still under the research process. The existing statistics indicates that global consumption of PGPRs during 2003 to 2013 increased from 16691 tons to 42700 tons, showing about 2.5 times more utilization. It is predicted that by 2020, annual consumption will be rising to 3.65 percent yearly. The market value of these compounds in 2013 was about 3.56 billion US dollars and is expected to be worth about 6 billion by 2020. In recent years, the consumption of these substances has increased in Iran, but till now precise recorded information not yet been available. In the following article, we have tried to address about production and consumption of these compounds and legal issues in Iran and the world.

Summer Savory (Satureja hortensis L.) is an annual, herbaceous plant belonging to the Labiatae family. This plant is most often used as a culinary herb, but it also has marked medicinal benefits, especially upon the whole digestive system. The most important components of S. hortensis include volatile oils, phenolic compounds, flavonoids and phenolic acids, tannins, mucus, resins, carotenoids and mineral components. Plant growth regulators are used to improve the quality and quantity of medicinal plant production. Salicylic Acid is one of this PGRs that involved in seed germination, photosynthesis, Stomatal opening and closure, Membrane Permeability, Ions Absorption and transmission and other growth processes. Polyamines are ubiquitous low-molecular-weight aliphatic amines that are involved in regulating plant growth processes. The most commonly found polyamines in higher plants, putrescine (Put), spermidine (Spd) and spermine (Spm) may be present in free, soluble conjugated and insoluble bound forms. It has been demonstrated that PAs are important for the normal course of diverse plant ontogeny processes such as cell division and elongation, organogenesis and somatic and zygotic embryogenesis.
This experiment was conducted in factorial based on a randomized complete block design with three replications in Karaj, Iran. Foliar spraying with SA (1, 2 and 3 mM.l) and Putrecine (50, 100, 150 and 200 mg l-1) was performed in thrice in Savory growth period. Spraying was performed at 21, 35 (Budding Phase) and 56 (flowering initiation phase) day after seed germination. In flowering stage, some morphological traits such as plant height, weight, yield, canopy diameter, stem diameter, leaf area, essential oil content and efficiency were measured.
Analysis of variance showed that the effects of salicylic acid and putrescine spraying on plant height, canopy diameter, stem diameter, number of axillary stems, foliage dry weight, foliage yield, flower dry weight, number of leaves, leaf dry weight, leaf yield, leaf area index (LAI), number of inflorescence, dry weight of inflorescence, total chlorophyll content, chlorophyll a and b content, essential oil content, yield and efficiency was significant (P This study revealed that foliar application of SA and putrescine significantly affected the morphological, physiological and biochemical traits of Satureja hortensis. Thus, it can be used as a plant growth regulator for yield and essential oil content improvement in field production of this plant.

Salinity is the one of the most important factors that limited growth and yield of crops. This study was developed to evaluate effects of abscisic acid (ABA) on seed germination, seedling growth and hypocotyl culture of rapeseed (Canola) genotypes at different levels of salinity. The research was arranged as a factorial experiment in a randomized complete block design with three replications. Genotypes at three levels, salinity at four levels and three levels of ABA were tested in this experiment. In a separate experiment hypocotyl explants were cultured in MS medium complimented with 2 mg lit-1 BAP (6-Benzylaminopurine) and 1 mg lit-1 NAA (Naphthalene acetic acid), under salinity and ABA treatments that mentioned in germination test. In separate consideration of ABA and salinity effects, both treatments were inhibited seed germination, seedling growth, callus induction and calli growth in all genotypes. The significant interactions between two factors indicated that genotypes had different responses to salinity in different concentrations of ABA. Most of germination traits that evaluated under different levels of ABA and salt stress differences were significant at 1% probability level. So that seeds had higher germination rate in 10 µmol/L ABA than 5µmol/L ABA in saline environments. In low levels of salinity (60, 120 mmol/L), callus induction and calli growth were performed more efficient using 5µmol/L ABA in comparison with no ABA treatment (at 1% probability level).

The Jatropha curcas L.، a plant belongs to Euphorbiaceae family، which has great economic and medicinally value. There is high amount of oil in seeds of this plant. Because of low germination ability of seed، propagation of Jatropha curcas via seed is not usual. The purpose of this work is optimizing of Jatropha curcas tissue culture for optimization of callus formation and propagation through micropropagation. The whole experiments were performed in complete Split- Factorial block design with nine replicates. In the current work the effect of different concentrations of 6-benzyladenine (BA) and indol-3-butyric acid (IBA) hormones (0، 0. 25، 0. 5، 1، 1. 5، 2، 3 mg/lit) in MS medium were investigated on callus and shoot formation on leaf، petiole stem and node explants. The results showed that the combination of BA and IBA is more effective for callus formation. The highest percentage of callus formation (90. 63%) was observed at 2 mg/lit BA and 1 mg/lit IBA in stem explants. The results showed that the highest percentage of shoot induction was observed at 0. 5 mg/lit BA and 0. 25 mg/lit IBA in node explants. Meanwhile our observations indicated that the root regeneration was happened equally at different concentrations، but the highest regenerated root number were observed after 0. 5 and 1mg/lit of IBA treatment. Finally، the obtained plants were transferred into soil medium.