فصلنامه فرآیند و کارکرد گیاهی
سال یازدهم شماره 1 (پیاپی 47، فروردین و اردیبهشت 1401)

The use of growth-promoting bacteria increases vegetative growth, and with it, timely consumption with appropriate concentrations of growth retardant can play a role in the distribution of nutrients to the shoots and roots, and thus improve dehydration tolerance. For this purpose, in this study, the reaction of the new super wheat cultivar SHS022 under the conditions of irrigation regime with the use of growth-promoting bacteria and the application of growth retardant paclobutrazol were investigated. This research was conducted as a factorial split plot in the form of a randomized complete block design with three replications in Qom and Hamedan in the 2018-19 crop year. The first factor includes the amount of irrigation with three levels (irrigation at 40% of available moisture discharge throughout the growing season (control), normal irrigation up to pollination stage and irrigation at 60% available moisture discharge until seed maturity, irrigation at 40% Moisture release available up to pollination stage and cessation of irrigation until the end of the growing season) and the second factor includes foliar application of paclobutrazol at three levels (0, 50 and 100 ppm) and the third factor including growth-promoting bacteria at five levels (control, Mycobacterium, Azotobacter and Azospirillium and combination). According to the results of analysis of variance, the main effects on chlorophyll fluorescence parameters, flag leaf relative moisture content, flag leaf chlorophyll content and Rubisco activity were significant. According to the results of comparing the mean in the first level of irrigation regime, there was no significant difference between paclobutrazol levels, but in the second level of irrigation regime, the highest percentage of relative leaf moisture was obtained at a concentration of 100 ppm paclobutrazol (66.23%), so that two levels Control and 50 ppm were in a lower statistical group (52.95 and 56.63%, respectively), but in the third level of irrigation regime, the highest trait was obtained at a concentration of 100 ppm paclobutrazol with 55.36% and The lowest was evident at the control level with 38.24%. The interaction effect of irrigation regime on paclobutrazol on Rubisco activity was significant so that in the first level of irrigation regime there was no significant difference between levels of paclobutrazol, but in the second and third levels of irrigation regime the highest amount of rubisco was 100 ppm paclobutrazol. They belonged to 37.63 and 29.27 units, respectively, and the lowest amount of trait was in the control factor.

The increasing population and high demand for cultivation of crops in the area with high salt concentration promoted the application of new strategies to improve plant tolerance to salinity stress. The present study was conducted to investigate the effect of potassium silicate (0, 10 and 20 mM) on reducing the harmful effect of salinity stress induced by sodium chloride (0, 100 and 200 mM) in radish. The experiment was performed as a pot experiment using a Randomized Complete Block Design with four replications. Salinity stress significantly reduced the chlorophylls content, chlorophyll fluorescence (Fv/Fm and PIABS), carbohydrates, proteins and plant biomass, while silicon treatment reduced the adverse effect of salinity stress on them. In response to salinity stress, proline, the activity of superoxide dismutase, H2O2 accumulation and membrane lipids peroxidation showed a significant increase, while the amounts of phenols, anthocyanins and FRAP antioxidant capacity of plants decreased. Silicon treatment increased phenols, anthocyanins and FRAP antioxidant capacity of salt stressed-plants, which was accompained with the reduction of H2O2 accumulation and subsequently reduction of membrane lipids peroxidation. Based on the results of present study, it can be suggested that silicon treatment reduced the adverse effect of salinity on the growth and yield of radish plant through the improvement in chlorophylls content and fluorescence, reduction of reactive oxygen species, and increasing the antioxidants and osmotic compatible solutes.

Gamma radiation is being used to induce mutation in diverse plant species. The present study investigated the growth and physiological responses of two tall fescue genotypes, 75C (native genotype) and Pacer (foreign genotype) to gamma radiation, as well as determination of the proper dose of gamma radiation for the mutation breeding program of this species. Seeds of two genotypes of tall fescue were subjected to different doses, including 50, 100, 150, 200, 300 and 400 Gray (Gy) of gamma ray from a 60Co (Cobalt-60) source. Irradiated and non-irradiated seeds were sown in pots and grown under controlled conditions in the greenhouse. Growth and physiological aspects associated with plant tolerance to oxidative stress were examined. The results revealed that the low dose (50 Gy) of gamma radiation stimulated seedling growth of both genotypes. However, high doses (100-400 Gy) significantly reduced seedling survival and plant height, and enhanced days to seedling emergence. Further, high doses of radiation reduced activities of antioxidant enzymes (especially catalase and superoxide dismutase), and increased the contents of proline and malondialdehyde (MDA) in the seedlings of both genotype as compared with non-iradiated plants. Biplot analysis indicated that positive correlations were found between the growth and survival of plant with antioxidant enzyme activities and negative correlations were obsereved between the plant growth and proline plus MDA contents. The native genotype (75C) was more sensitive to gamma-ray than Pacer genotype. According to the probit analysis, the 50% lethal dose (LD50) for 75C and Pacer genotypes were 212 and 223 Gy of gamma radiation, respectively. Based on the results of the present study, gamma rays stress negatively affected survival, morphological traits, and antioxidant enzymes activities in tall fescue and dosages ranging from 200 to 250 Gy is recommended as the appropriate dose of irradiation for mutation breeding programs in tall fescue.

The use of appropriate biological and organic fertilizers has been a prominent technique in the yield promotion and quality improvement of horticultural crops. In Present study, the effects of three commercial fertilizers; Stimplex (biofertilizer), Essential plus (organic fertilizer), Fertigofol (Complete fertilizer) as well Nano-chelate potassium on the quality and yield of two commercial strawberry cultivars (Albione and Gavietta) were evaluated. Traits including number of leaves and flower buds, petiole length, fruit firmness and yield of each plant, chlorophyll and anthocyanin content, antioxidant activity and Total soluble carbohydrate were measured. The longest petioles (15.2 cm) and the highest number of leaves (11.6) per plant were related to Gavita cultivar under stimplex biofertilizer treatment, while the shortest petiole (11.1 cm) was also affected by the same fertilizer(stimplex) in Albion cultivar. The highest and lowest total soluble carbohydrate content was obtained under potassium nano-chelate and stimplex treatments in both cultivars, respectively. Fruit firmness in Albion cultivar under all tested treatments was significantly higher than Gavita, but the highest fruit firmness was obtained with stimplex biofertilizer. The results revealed that although there were considerable variations among measured parameters as well cultivars in response to tested treatments, but the suitable treatments were Stimplex and fertifogol and then nano-chelate potassium. In short, "Gavietta" attained more score in most of measured attributes higher than "Albione. Considering the traits responses to the fertilizers, Stimplex and Fertifogol fertilizers showed more positive effects on the quality and quantity of strawberry fruits and hence,"Gavietta" was the cultivar of choice.

The Proveskia abrotanoides Karel is one of the valuable medicinal species in Iran, and its products have been using in the traditional culture of the people for the prevention and treatment of diseases since long time ago. In this study, in order to investigate the effect of habitat on the phenolic, flavonoid and essential oil contents, sampling of plant branches in full flowering stage with three replications were randomly done from natural habitats of Raz and Jargalan county of North Khorasan province, including Tangeh Torkman district (with height of 995 m), Goynik (with height of 1207 m) and Cheshmeh Seyed (with height of 1450 m). The results of present study showed that the effect of habitat condition was significant on the content of phenolic compounds, flavonoids and essential oil and Cheshmeh Seyed habitat with 115 phenolic content (mg GA/g D.W), 640 flavonoid (mg Q/g D.W) and 1.47 persentage of essential oil showed the highest amounts of these compounds, respectively which can probably be considered as confirming the beliefs of the native people of the province that they collect and consume more Proveskia abrotanoides from mountainous areas. In the study of the type and the amount of compounds of essential oil, a total of 33 compounds were identified, of which 1,8 Cineole, Camphore, Caryophyllene and Alpha-Humulene were the main compounds of essential oil in this study area. Due to the fact that the medicinal value of Proveskia abrotanoides essential oil depends on the percentage of 1,8 Cineole, Camphore and Caryophyllene, in this study it was observed that essential oil of the Cheshmeh Seyed district has a higher percentage of these compounds and it can be concluded that the best place for the growth of this plant in the region to achieve the best yield quality and quantity of essential oil is Cheshmeh Seyed habitat.

Foliar application of micronutrient such as zinc is a quick and easy way to eliminate or reduce the deficiency of these nutrients in plants. In order to evaluate the effects of foliar application of ordinary and nanoparticles of zinc on the growth and antioxidant responses in medicinal plant basil (Ocimum basilicum L.), this research was conducted by complete randomized design with three replicates under greenhouse conditions. The treatments were four levels zinc oxide (0, 25, 50, 100 mg.L-1) and four levels zinc oxide nanoparticles (0, 25, 50, 100 mg.L-1). Results showed that under zinc oxide treatment at 100 mg/L, the shoot and root length, and the shoot and root dry weights were significantly increased, in compare to control. The zinc nanoparticle treatment under different levels, especially at 100 mg.L-1 had a significant increase on all growth parameters including shoot and root length, inflorescence number and length, and shoot and root dry weights in comparison to control plants. By increasing concentration of both treatments (ordinary zinc and nano-zinc), the activities of antioxidant enzymes catalase, ascorbate peroxidase and guaiacol peroxidase were elevated. Minimum and maximum amounts of growth traits and antioxidant enzymes activities were observed in control and 100 mg.L-1 zinc nanoparticle, respectively. The results from this study indicate positive and obvious effect of zinc oxide nanoparticle, compared to ordinary zinc oxide, on the growth and antioxidant enzyme activity in pharmaceutical plant basil.

Seed aging is a phenomenon that causes a lot of economic losses every year and it is necessary to use new and efficient methods to deal with it. B vitamins have a defensive and antioxidant role and they are effective in growth and development, so it is possible that they can heal the effects of seed aging. For this purpose, an experiment was conducted at Shahrood University of Technology in March 2017 to investigate the effect of seed pretreatment with B group vitamins on the growth and yield of canola in seed deterioration conditions. The experiment was factorial based on randomized complete block design with 3 replications. Experimental treatments were 3 levels of seed deterioration (0, 50 and 100 hours) and 7 levels of seed pretreatment with B vitamins (No pretreatment, Distilled water, thiamine, Riboflavin, Niacin, Pantothenic acid and Pyridoxine) with a concentration of 100 mg/l. Seed deterioration was done at 40⁰C and seed pretreatment for 8 hours. The  results showed that all the measured traits were decrease affected by seed deterioration and only the amount of anthocyanins increased. In severe deterioration, seed pretreatment with distilled water and pyridoxine increased protein and oil yield respectively. Pantothenic acid pretreatment increased the amount of anthocyanins, total chlorophyll and grain yield at severe deterioration levels. This treatment increased grain yield by 143 percent compared with plants grown from seeds without pretreatment. In general, among the treatment investigated in this study, the pretreatment of seeds with pantothenic acid and thiamine improved and increased many traits such as seed yield, oil and protein content. The advantage of these treatments was quite obvious in normal seeds but in aged seeds there was no significant difference with distilled water. Therefore, the results showed that in aged seeds, a similar result can be achieved by using distilled water with less cost.

One of the methods of remediation and cleaning of soils contaminated with heavy metals is the use of organic compounds such as vermicompost to purify or stabilize the contamination. In this study, the effect of vermicompost on the uptake of heavy metals lead and cadmium by ornamental sunflower and the effect of these metals on germination and plant establishment characteristics were investigated. This study was carried out in two experiments of germination and greenhouse in 1397-98 in Islamic Azad University, Arak Branch in a factorial way in a completely randomized design. In the first experiment, concentrations of 50, 100 and 200 mg / l of lead nitrate and cadmium chloride were used and then germination indices were evaluated. In the second experiment, concentrations of 0, 5, 10 and 15 mg/kg of lead metal, concentrations of 0, 400 and 600 mg/kg of cadmium and three levels of 0, 15 and 30 kg/m2 of vermicompost to the ability to uptake heavy metals were used by ornamental sunflowers. The results of the first experiment showed that increasing the concentrations of heavy metals lead and cadmium reduced the length of root, shoot and germination indicators such as seed vigor index, germination rate index and average germination rate. The results of the second experiment showed that by increasing the concentration of lead and cadmium in the soil, the number of leaves and shoot length of ornamental sunflower decreased and the amount of soil and lead cadmium, lead and cadmium root and lead and cadmium shoot increased. The study achieves that H. annuus "Sungold" plant showed tolerance to lead and cadmium contamination and we recommend its capacity for the remediation of lead and cadmium contaminated soils. The activity of the enzyme superoxide dismutase also increased as the concentration of heavy metals in the culture medium increased. Vermicompost implementation was able to partially improve the negative effects of these heavy metals. With increasing the concentration of heavy metals, the activity of superoxide dismutase increased by 30-50% compared to the control. Vermicompost reduced the amount of these metals in the soil, roots and stems of the ornamental sunflower plant, and this ornamental plant can be introduced as a purifier of lead and cadmium contaminated areas.

In order to investigate the effect of plant density and foliar application of kaolin on rainfed wheat cultivars, a factorial-split plot study was conducted in a RCBD with four replications under rainfed conditions in Koohdasht. Plant density factor viz. 350, 500, 650 and 800 plants per square meter and cultivar factor including three dryland wheat cultivars Karim, Kuhdasht and Qaboos as factorial in main plots and kaolin foliar application in two levels of non-application and application of Kaolin was placed in sub-plots. The results showed that with increasing plant density, the amount of polyphenol oxidase and peroxidase antioxidants (26.2% and 9.1%, respectively) and grain carbohydrates (11.9%) increased, but the amount of grain protein (4.3%) decreased, at the highest density compared to the control. The amount of nitrogen, potassium and iron in the grain decreased with increasing plant density. The highest amount of phosphorus, zinc and grain protein belonged to Qaboos cultivar, so that in Qaboos cultivar the amount of phosphorus was 6.4% and 1.9%, respectively, the amount of zinc was 4.6% and 1.3%, respectively, and the amount of protein was 2.5% and 0.3%, respectively, more than Karim and Kuhdasht cultivars. Foliar application of kaolin increases the uptake of all essential elements studied in the shoot and the amount of nitrogen, phosphorus, iron, zinc and carbohydrates in the grain; but reduces the antioxidants of the shoot and the amount of potassium and protein in the grain compared to the non-use of kaolin. In total, Qaboos cultivar at a density of 500 plants per square meter with the use of kaolin was recommended as the best treatment for grain production and enrichment at Kuhdasht region.

The use of ornamental plants in phytoremediation has attracted a lot of attention due to preventing the entry of heavy metals into the food chain and their beauty in the environment.  Today, tissue culture technique is used as a model system to predict the plants response to environmental pollutants. In the present study to investigate the ability of Narcissus tazetta L. in remediating the environment of cadmium contaminants, in vitro micropropagation of this ornamental plant was done by three procedures: induction, proliferation and bulb production. Then these plantlets were treated by cadmium chloride in three concentrations (1, 2 and 5 mM) in solidified MS culture medium for two weeks. The results showed that Narcissus plantlets are able to accumulate large amounts of cadmium and by increasing cadmium concentration in the medium, its accumulation in plantlets increases; So that in 5 mM treatment, the amount of cadmium in the roots, bulbs and leaves of plantlets was 7502.84, 1971.45 and 398.60 µg g-1DW, respectively. Increasing the concentration of cadmium in the medium caused a decrease in dry weight, amount of pigments, uptake of zinc and peroxidase activity.  In 1 mM cadmium chloride treatment the tolerance index was 0.95 that by increasing cadmium concentration, the tolerance of plantlets decreased. Transfer factor of plantlets were less than one and bioconcentration factor was more than one, indicating that Narcissus can be suggested as a suitable alternative for cadmium contaminant phytostabilization of course requires further research on the soil.

Carrageenan and salicylic acid are bio stimulants that are involved in stress resistance by affecting the physiological and biochemical processes of the plant. In this study, carrageenan in two concentrations of 0.5 and 1 g / l and salicylic acid in 0.5 and 1mM concentrations were used for foliar application. This study was performed by factorial experiment in a completely randomized design with three replications. The pretreatments were applied in 6-leaf stage and the solutions were sprayed on the plant five times in the early morning in 10 days. One day after the last pretreatment, a number of pots were transferred to the refrigerator for 24 hours at a temperature of 5 °C for chilling stress, then the pots were returned to the greenhouse and after one day, samples of plant were collected from control and cold tressed pots. In this study, it was observed that pretreatment of plants with carrageenan and salicylic acid increased all growth parameters, osmolytes (include soluble sugars and proline), antioxidant enzymes include catalase, ascorbate peroxidase and guaiacol peroxidase activity, but reduced the oxidative stress index such as ion leakage, malondaldehyde and hydrogen peroxide content. The best results were obtained with the use of carrageenan 1 g / l and 0.5 mM salicylic acid. These results indicate that carrageenan and salicylic acid increased the resistance to cold stress in Impatiens flowers by increasing the protective parameters of the plant.It seems that these compounds as bio stimulants can be suitable for managing cold stress in other ornamental plants and can be used to reduce the chilling stress of autumn and winter in plants.

AbstractEnvironmental pollution and weed resistance to herbicides have attracted the attention of researchers to methods of biological weed control. In this regard, the effect of different concentrations (50, 100 and 150 mL/L) of different organs (roots, shoots, whole plant) of chamomile on some physiological parameters and initial growth of charlock mustard (Sinapis arvensis L.) and wheat (Triticum aestivum L.) were examined. The factorial experiment was performed in a completely randomized design with three replications. The results showed that increasing the concentration of chamomile extract increased hydrogen peroxidation, lipid peroxidation, and proline content of charlock mustard, however it suppreseed cell viability, germination rate, seedling length, seedling dry weight and seedling vigor index of this plant. The dry weight of charlock mustard and wheat seedlings at a concentration of 150 mL/L at the 5% probability level was 58.9 and 84.3, respectively. In other words, this trait decreased by 41% and 15.7% in the two plants. Although chamomile shoot extract had the most negative effect on the mentioned traits in both plants, charlock mustard showed a more severe response compared to wheat. Even with the lowest concentration, chamomile extract reduced the vigor index of charlock mustard seedlings three times more than that of wheat. In general, it can be concluded that based on the strong effect of chamomile extract on suppressing the growth of charlock mustard and little effect on wheat seedlings, it can be

In order to investigate the effect of organic fertilizers including compost and manure on morphological, yield and qualitative characteristics of Rosa damascena Mill, an experiment was conducted in a randomized complete block design with 7 treatments in 3 replications in 2018-2019 in Sirjan city. The treatments were compost (20, 25 and 30 tons per hectare) and manure (10, 15 and 20 tons per hectare) along with control (without fertilizer application). Results showed that fertilizer in all investigated characteristics was significant. Mean comparison of data showed that 20 tons / hectare manure responded better regarding to canopy, height, leaf length and width, fresh and dry weight of flowers, number of flowers, phenol, chlorophyll, and antioxidant. As well, 30 tons / ha compost  showed  maximum in number of branches, leaves per plant, fresh and dry weight per plant  and essential oil yield. Also, cluster analysis showed that 20 and 30 tons / hectare manure and compost were put in the same group. As conclusion, 20 and 30 tons / hectare manure and compost, respectively, had the maximum effect on morphological and qualitative characteristics of Rosa damascena Mill seedlings.

Nanoparticles depending on the plant species, methods used, culture conditions, concentration, etc. may have different effects on the induction of physiological and metabolic processes in plants. In this study the effects of different levels of silicon nanoparticles (0, 75, 150 and 300 mg/L) and salinity stress (0, 50 and 100 mM NaCl) were investigated as a factorial experiment based on completely randomized design with three replications under hydroponic culture conditions on morphological, physiological and biochemical parametres of Calendula officinalis L. plant. Scanning Electron Microscopy (SEM) confirmed the adsorption and translocation of silicon nanoparticles through leaves and roots upon experimental treatments. The results of analysis of variance (ANOVA) showed that the interaction effects of silicon nanoparticles and salinity stress on all measured traits were significant (P <0.05). Results showed that salinity stress reduced plant height, shoot dry weight, number of capitols, the largest flower diameter, flower yield, total chlorophyll and carotenoids and leaf relative water content.In contrast, the application of silicon nanoparticles reduced the negative effects of salinity stress (lipid peroxidation), improved growth parameters, photosynthetic pigments, quantitative (flower production) and qualitative (quercetin content) yield of the plant compared to the control, and there was a statistically significant difference in this regard between silicon nanoparticle levels. The results of analysis of extracts by HPLC showed that the highest amount of quercetin (309.78 μg/g dry weight) was related to the treatment of 150 mg/L silicon nanoparticles and salinity stress of 50 mM. Also, the antioxidant activity of plant flower extracts in different experimental treatments showed a significant (P <0.01) difference on inhibition of DPPH free radicals and had a similar trend with phenolic and flavonoid contents. Therefore, the use of appropriate concentration of silicon nanoparticles is effective in reducing the negative effects of salinity stress and increasing the content of pharmacologically active metabolites in marigold.

Survival of ornamental plants is vital green spaces threatened by climate change and drought stress. An experiment was designed to investigate the effect of soil modifiers on the growth of two plants of the Hollyhock ecotype under drought conditions at Ferdowsi University of Mashhad in 2021. Experimental Treatments included two ecotypes (Mashhad, Tehran), three drought stress levels (80, 60, 40% FC), and four substrates (soil, soil + manure, soil + rice hull, soil + wheat straw). Macroelements (nitrogen, phosphorus, and potassium) of leaves, physiological characteristics of plants, such as (total chlorophyll, proteins, and activity of enzymes), and morphological traits (height, the diameter of the stem, number of leaves, bud, flowers, and leaves the area) have been measured. The effect of time on the number of Hollyhock leaves under drought stress was also recorded. Treatments affected all physiological and growth parameters of Hollyhock plants, and a significant amount of physiological traits (chlorophyll) and growth parameters were recorded in the Mashhad ecotype below 80% FC in soil + manure. The triple interactions of ecotype, drought stress, and culture medium on protein content, superoxide dismutase activity, and ascorbate peroxidase activity were not significant, but enzyme activity was increased with increasing drought stress. Also, the number of leaves and flowers had a decreasing trend with increasing drought stress. The results showed that applying manure with soil by providing macro elements reduced the adverse effects of drought stress in Hollyhock and increased drought stress resistance in both ecotypes.

Lack of rainfall and rising temperatures have caused problems in the agricultural crop cultivation in many areas. Grapevine is one of the most important economic products in horticulture. Due to the importance of grapes as important economic products in horticulture, identification and use of resistant cultivars to drought stress is one of the basic steps and the important goals this plant breeding programs. This research carried out in factorial experiment in randomized complete design with three replications in 2020. Experimental factors was include different levels of drought stress (level four 100, 75, 50 and 25% of water requirement) and grapvine cultivars (Gharashiliq (Ga), Rasmi (Ra), Aghshiliq (Ag), Copake Bogan (Co), Tukilgen (Tu) , Khalili (Kh)). The results of this study showed that with increasing drought stress level in 6 grape cultivars, plant growth parameters, relative leaf water content, photosynthetic pigment content decreased significantly (p <0.01), that the greatest decrease was observed at the stress level of 25% water requirement. Also, increasing drought stress levels the electrolyte leakage, malondialdehyde, total soluble sugars, proline and antioxidant enzymes activity content increased in more cultivars, significantly (p <0.01). Increasing drought stress to 25% field capacity, the highest and lowest leaf area decrease percentage compared to the control were observed in Copake Bogan (68%) and Gharashilig (45%) cultivars, respectively. Among the studied cultivars, the highest and lowest ion leakage content were observed in Aghshilig and Gharashilig cultivars, which had 36% and 32.8%, respectively. The highest proline content was obtained in Gharashilig cultivar (0.14 µmol g-1 FW) and the lowest was obtained in Copake Bogan cultivar (0.067 µmol g-1 FW). Also, The highest and lowest catalase enzyme content among the 6 studied grape cultivars were obtained in Gharashilig cultivar (3.02 µmol g-1 FW.min) and Copake Bogan (1.41 µmol g-1 FW.min). The highest peroxidase enzyme content was obtained in Tukilgen (5.86 µmol g-1 FW.min) and the lowest content in Rasmi (1.39 µmol g-1 FW.min) cultivar. The results showed, Aghshiligh and Copake Bogan cultivars were drought-sensitive and Garashiligh cultivars drought-tolerant and the rest are semi-drought sensitive cultivars.

Drought is one of the most serious threats in agricultural production worldwide, and climate change is likely to exacerbate this threat. In order to evaluate the drought tolerance of different castor ecotypes, a factorial experiment was conducted in a completely randomized design with three replications in Sari Agricultural Sciences and Natural Resources University. The first factor was 22 castor ecotypes and the second factor was drought stress with 5 levels, full irrigation, four levels (irrigation was cuted at the primary of spike growth) (11, 22, 33, 44 days after Irrigation cut off). Experimental traits were included the activity of the antioxidant enzymes Catalase, Guaiacol peroxidase and Ascorbate peroxidase, the biochemical activity of Malondialdehyde (MDA), Proline content, Plant height, stem diameter and number of leaves. Cluster analysis classified the ecotypes into three clusters under normal and drought stress conditions.The results showed that the activity of Catalase, Ascorbate peroxidase, Guaiacol peroxidase, Malondialdehyde and Proline content under drought stress conditions of the third group (Tolerant) compared to the first group (Sensitive) were increased 81.5, 81.87, 70.27, 80.05, 81.87, respectively. On the other hand, the differences between tolerant and sensitive groups at stress conditions in plant height, stem diameter and number of leaves were 74.74, 80.50 and 83.38%, respectively. The highest correlation under drought stress conditions was observed between Catalase and Ascorbate peroxidase (r = 0.997) and the lowest non-significant correlation was observed between proline and plant height (r = 0.292). According to the results, in terms of the studied traits 5 and 19 ecotypes were introduced as drought tolerant ecotypes.

Considering the increasing trend of drought development and lack of desirable land for agriculture in the world, the use of drought resistant species or the use of compounds that reduce the effects of drought stress and induction of resistance to stress in plants is very important. In the present study, the effects of salicylic acid (SA) foliar spray (0, 0.5 and 1 mM) on physiological and biochemical responses of purslane (Portulaca oleracea L.) as a medicinal plant under drought stress (90, 60 and 30% of field capacity (FC)) were examined in a factorial experiment based on a completely randomized design with four replications in Islamshahr Branch, Islamic Azad University, Islamshahr, Iran. The results showed that 60 and 30% FC reduced the height (18.5 and 45%, respectively) and total dry weight (43.1 and 58.6%) of the plant compared to the control treatment. Drought stress, especially 30% FC, reduced photosynthetic pigments, relative water content, membrane stability and induced oxidative stress (increased levels of methylglyoxal and malondialdehyde). However, foliar application of SA by regulating chlorophyll metabolism (activity of chlorophyllase and delta-aminolevulinic acid dehydratase) and improving proline metabolism (activity of proline dehydrogenase and delta-1-proline-5-carboxylate synthetase 1) increased the contents of chlorophylls and proline and, consequently, improved photosynthetic apparatus efficiency and relative water content under drought stress. SA also improved plant tolerance to drought stress by increasing the activity of enzymes involved in the glyoxalase system and improving the redox state of the ascorbic acid-glutathione cycle. Therefore, SA under drought stress can play an effective role in reducing and modulating the negative effects of stress.

Sweet pepper is one of the most important commercial vegetable with short postharvest life and high susceptibility to fungal diseases. This research was conducted based on complete randomized factorial design with two treatments of UV-C radiation (0, 5 and 10 kJ m-2s-1) and DPI dipping (0 and 1 µM) with 3 replication on sweet pepper fruits. The effects of these treatments was studied on some attributes changes throughout 28 days at 7ºC. The results showed that carotenoid content reduced during 28 days of storage. Treatment of 5 kJ m-2s-1 UV-C and combination of 10 kJ m-2s-1 and DPI treatment caused an increase in carotenoid content that generally kept the same values than initial value after 28 days at 7 ºC. After 10 kJ UV-C m-2 treatment an important initial stress was foundand treated samples conserved antioxidant contents regarding the initial content. In these samples DPI dipping generally reduced the antioxidant capacity on the 28 day.  The medium illumination dose showed the highest total phenolics content and reducing sugar. Combination of 10 kJ UV-C m-2 illumination and DPI treatment caused conservation of protein content after 28 days at 7 ºC. SOD activity increased on 21th day of storage in treated samples with 5 kJ m-2s-1 UV-C and 1 µM DPI[RbD1] . 10 kJ UV-C m-2 caused an increase in catalase activity on the last day of storage. Illuminated samples with 5 kJ UV-C m-2 showed the highest peroxidase activity on 14th day at 7 ºC. As main conclusion a pretreatment of UV-C radiation and DPI dipping was found as an effective technique for quality preservation of sweet pepper fruits during storage. [RbD1]Which concentration?

Due to climate changes and Deficiency of water resources, as well as the importance of cultivating ornamental plants in green space, in order to better water management, an experiment to investigate the effect of water deficit sress and foliar application of different concentrations of selenium on some morphophysiological and biochemical characteristics of Scarlet sage, in factorial experiment based on a completely randomized design with three levels of water deficit stress (90 (control), 80 and 70% of field capacity) and four levels of sodium selenate (0, 0.5 and 1.5 μM) were performed in greenhouse conditions. Experiment results showed that water deficit stress decreased plant height, leaf area, flower longevity, relative leaf water content and increased electrolyte leakage and malondialdehyde concentration. Application of selenium at concentrations of 0.5 and 1 μM by increasing the activity of catalase, ascorbate peroxidase and peroxidase enzymes increases plant height, leaf area, flower longevity, relative leaf water content and reduces electrolyte leakage, malondialdehyde concentration and also increases relative it was photosynthesized at the concentration of pigments but at a concentration of 1.5 μM had a negative effect on the mentioned properties. In general, the results showed that under water deficit stress has a detrimental effects on plants growth and development. Selenium in water deficit stress and non-stress conditions at low concentrations improved the vegetative and reproductive growth of plants but at higher concentrations had a negative effect on these parameters.