جستجوی مقالات مرتبط با کلیدواژه « antioxidant activity » در نشریات گروه « زراعت »

The genetic diversity of plant species and their relationship with wild species is very important to improve the yield of crops..The first step in the improvement of medicinal plants is to identify and collect endemic genotypes.Endemic genotypes are very important in the selection of cultivars due to their adaptability to the climate of the region. Mentha longifolia is one of the important endemic medicinal plants of Iran, which is used in various pharmaceutical, food and cosmetic industries. Essential oil, phenolic compounds, flavonoids and other compounds such as steroids and ceramides are important chemical compounds in oregano plant. In this study, morphological diversity, essential oil and antioxidant activity of 20 Mentha longifolia genotypes in West and East Azerbaijan provinces were investigated. The aim of this research, on the one hand, is to know the potential and range of diversity of Menta longifolia genotypes in its natural habitats in West Azarbaijan and East Azarbaijan provinces. On the other hand, the introduction of regions with superior genotypes in terms of these traits is for use in breeding programs.

The collection of plant samples from some areas of two northwestern provinces of Iran (West Azerbaijan and East Azerbaijan) was done in the spring of 2022. In order to evaluate the morphological traits of the plant in the flowering season, 11 quantitative traits of the plant including plant height, inflorescence length, crown diameterstem diameter, internode length, leaf length, leaf width, number of leaves, number of inflorescences, fresh weight, dry weight and the number of sub-branches were evaluated. After drying the plant samples, essential oil extraction was done using a clonger, and the essential oil samples were transferred to Urmia University Jihad to identify compounds by gas chromatography. Extraction of plant samples was done by ultrasonic method .Antioxidant activity was evaluated by DPPH method. All the obtained data were analyzed with three repetitions and based on a completely random design using SPSS software .LSD test was used to compare the mean data. Data clustering was done based on Ward's method and Euclidean distance square measure. Principal component analysis was performed on the data .Also, in this study, correlation between studied traits was done by R software.

The results of analysis of variance showed that the genotypes collected from different regions have significant differences in terms of plant height, inflorescence length, crown diameterstem diameter, internode length, leaf length, leaf width, number of leaves, number of inflorescences, fresh weight, dry weight and the number of sub-branches are investigated (P < 0.01). The results of the analysis of the percentage and chemical composition of the essential oil showed that the type of genotype had a significant effect on the amount of these compounds in different genotypes of Mentha longifolia (P < 0.01). Among the studied genotypes, the highest percentage of essential oil and the amount of Trans-Caryophyllene and Germacrene D compounds were found in G18 of Iranq region of Tabriz, also the highest amount of Alpha-Terpineol and Spathulenol was found in G16 of Aghajari region of Maragheh. Also, there was a significant difference between different genotypes of mint in terms of antioxidant activity. The maximum amount of antioxidant activity (80.81%) was observed in G3 of Hachesu area in Shahindej. Based on Ward's cluster analysis, the genotypes were divided into three main groups. G1 alone was placed in a separate group due to the high content of Spathulenol and high antioxidant activity. The second group, which includes most of the genotypes (G2, G3, G5, G16, G19, G17, G20, G12, G14, G4, G6, G8, G11, G13, G9, G7 and G10), has a moderate amount of morphological traits, essential oil components and antioxidant activity. G15 and G18 genotypes were placed in the third group. The prominent features of these genotypes were high values of length and number of inflorescences, length and width of leaves, number of leaves, fresh and dry weight of the plant, number of sub-branches, percentage of essential oil, alpha-Humulene, trans-Caryophyllene and GermacreneD and antioxidant activity.Using principal component analysis, 21 primary variables were determined in the form of two principal components.The first component explained 40% and the second component 19% of the total variance. The results of correlation analysis showed that there was a positive and significant correlation between the percentage of essential oil and some morphological traits, the percentage of essential oil and the amount of Germacrene D, trans-Caryophyllene, beta-Farnesene and isomenthon, as well as antioxidant activity and morphological traits.

The findings of this study showed that G15 belonging to Maragheh with an altitude of 1776 m had the highest number of leaves, length and width of leaves, fresh weight, dry weight and number of sub-branches, internode length and number of inflorescences compared to other genotypes.Therefore, it can be said that this genotype has priority for breeding, domestication and crop cultivation projects and is suitable for its introduction to the market as a medicinal plant.In addition, the results showed that the highest percentage of essential oil and the amount of compounds such as Germacrene D, Trans-Caryophyllene, Spathulenol, Beta-Farnesene, Alpha-Terpineol were obtained in genotypes with high altitudes.

Nowdays, because of human industrial activities, ozone layer depletion increases the amount of ultraviolet (UV) irradiation that reaches Earth’s surface; creating problems for living organisms. Since plants always need sunlight, the effects of UV radiation on plants are inescapable. The present study was conducted to evaluate the physiological, phytochemical and chlorophyll fluorescence responses and stomatal characteristics of three cornflower cultivars to UV radition in 2018.

The experiment was performed as a split plot in a completely randomized design. Ultraviolet light was considered as the first factor in four levels (control, ultraviolet A, ultraviolet B and ultraviolet A + B) and three cornflower cultivars as the second factor. When seedlings had four real leaves, the UV treatments were started by ultraviolet lamps made by Q-Lab company of the USA. At the end of experiment, physiological and phytochemichal traits including relative water content, electrolyte leakage, lipid peroxidation, chlorophyll a and b, carotenoid content, catalase and peroxidase activity, stomatal gurad cell length and width, stomatal index, stomatal density, chlorophyll fluorescence, phenol and flavonoid contents, anthocyanin, and antioxidant activity of extract were assayed. The analysis of variance was done using Minitab software according to the experimental desing. Mean comparison was performed using LSD test method at 0.05.

The results showed that the amount of malondialdehyde, electrolyte leakage and antioxidant enzymes activity was increased under UV-B radiation. UV-B radiation decreased leaf chlorophyll content, but increased carotenoids. UV A had no significant effect on chlorophyll, while, increased carotenoids. Maximum fluorescence, variable fluorescence and maximum quantum efficiency of photosystem ІІ were reduced under UV treatment. In contrast, UV radiation increased the minimum of fluorescence. UV-B and UV-A+B radiation increased width of stomatal gurad cell, and stomatal index and density, but decreased length of stomatal gurad cell in cornflower. The amount of flavonoids, total phenol, anthocyanin and antioxidant activity of cornflowers increased by UV radiation. Among the cornflower cultivars studied, Kornblume blau cultivar had shown the highest values of total phenol, total flavonoids and anthocyanins as well as antioxidant activity.

In the present study, UV-B radiation and simultaneous UV-A+B radiation led to more extensive physiological and phytochemical responses in cornflower cultivars. Based on the results obtained in this study, it can be concluded that UV-B has more destructive effects than UV-A on cornflower. In the comparison between cultivars, it was found that Kornblume blau cultivar is more suitable for medicinal use due to its higher phytochemical compounds and biological activity.

In agricultural systems, several environmental stresses can remarkably alter the growth, physiological, and biochemical responses of plants under stress. One of these factors is the biochemical reactions between plants along with the production of secondary compounds. Allelochemicals mainly have defence and cell wall ligninization roles in plants and do not directly play a role in the growth processes of plants. Thus, an experiment was carried out to evaluate the effect of allelopathic stress of Hypericum perforatum on the germination, physiological, biochemical, and antioxidant activity characteristics of green pea, the benchmark plant sensitive to allelochemicals.

The treatments included different concentrations of H. perforatum at 11 levels (i.e., 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100% of the aqueous extract). This research was carried out as a completely randomized design with three replications at the weed science laboratory of Gonbad Kavous University in 2023.

The results of this study showed that one of the factors influencing the physiological, and biochemical characteristics of green pea is the concentration of the H. perforatum extract. In most cases, the percentage and rate of green pea germination, radicle and plumule length, and dry weight of radicle and plumule decreased with increased concentration of aqueous extract compared to the control, so that the greatest reduction in these characteristics was observed in 100% of H. perforatum extract. In contrast, the content of compatible osmolytes such as proline and soluble sugars, phenolic and flavonoid compounds, and antioxidant activity of green pea roots and plumules increased significantly in all studied treatments, with the highest increase in these characteristics observed at the concentration of 100% of H. perforatum aqueous extract. In general, the decrease in the dry weight of green pea seedlings due to the increase in the concentration of the aqueous extract of H. perforatum, despite the relative increase in the content of physiological and biochemical traits, indicates the high intensity of allelopathic stress of H. perforatum extract and their insufficiency, which leads to cytotoxicity against oxidative stress.

Considering the heterotoxicity effect of H. perforatum on green pea sensitive to allelochemicals and its distribution in gardens, barren lands, and wheat and corn fields, the possible effect of their residues in the next planting and even in case of presence in mixed cultivation should be considered.

Climate change is a very serious threat to crops production in all regions around the world. Heat stress is a consequence of climate change that affects biochemical, physiological and molecular processes of crop plants, causing alterations in crop growth, development, and productivity. Terminal heat stress is the most widespread and type of heat stress in the world that limits crop productivity and ultimately food security. Sunflower is moderately tolerant to heat stress. It can tolerate higher temperatures without suffering from heat stress. However, sunflower is more susceptible to heat stress from early flowering to grain filling. Hence, it may be severely damaged when exposed to terminal heat stress. Biochemical and physiological responses in crop plants are modified under heat stress. It has been shown that tolerance to heat stress in crop plants is associated with an increase in antioxidant enzyme activities. The physiological and biochemical responses to heat stress vary among crop plant species and genotypes which can be used for development of cultivars with high temperature tolerance in crop plants.

This experiment was carried out in 2017-2018 growing season in Ahvaz, Iran, using as split-plot arrangement in randomized complete block design with three replications. Main plots consisted of three sowing date including; 11th November, 11th December and 11th Janauary, and five sunflower cultivars including; Qasem, Fantasia, Shams, Lakomka and Progress were randomized in sublpots. Sowing on 11th November was considered as normal sowing date, and sowing on 11th December and 11th January were delayed and late sowing dates, respectively. In the two latter sowing dates, flowering and grain filling periods were exposed to moderate and severe terminal heat stress.

Terminal heat stress in delayed and late sowing dates caused significant reduction in carotenoid content (27% and 56%, respectively), seed yield (30% and 32%, respectively) and oil yield (18% and 28%, respectively), but increased catalase (63% and 55%, respectively), peroxidase (107% and 56%, respectively) and superoxide dismutase (43% and 67%, respectively) enzyme  activities, carbohydrate concentrations (18% and 30%, respectively) and malondialdehyde concentration (46% and 98%, respectively), when compared to normal sowing date. There was significant differences among sunflower cultivars for most of studied traits. Lakomka cultivar with the highest values of biochemical and physiological indices such as chlorophylle content, antioxidant enzyme activities and carbohydrates concentration and with the lowest malondialdehyde concentration had the highest seed yield (1579 kg.ha-1) and oil yield (608 kg.ha-1) under terminal heat stress.

Exposure to moderate and severe terminal heat stress differently influenced physiological and biochemical traits in sunflower cultivars. The severity of terminal heat stress played an important role in the cultivars responses. Progress cultivar had the lowest reduction in oil and seed yield under terminal heat stress, however, cv. Lakomka showed highest seed and oil yield in all three sowing dates. Therefore, it can be concluded that cv. Lakomka is suitable for being sown in normal, delayed and late sowing dates due to least variability in its seed yield.

Drought is one of the major environmental stress induced by global climate change that adversely affects the growth and development of plants and causes significant yield losses in the oil seed crop, safflower. Drought stress adversely impacts growth and productivity with various physiological and biochemical processes such as stomatal conductance, photosynthesis, chlorophyll content, carbohydrate metabolism, lipid peroxidation, and antioxidant defense system. As, the water resources used for irrigated agriculture are decreasing in many agricultural regions of the world, therefore, irrigation management under water scarcity is increasingly important. Various deficit irrigation management strategies have been developed in different agroclimatic regions to improve crop performance under water deficit conditions. However, It is very important to develop crop management strategies that make plants suited for stressful environmental conditions

In order to study of deficit irrigation management on physiological and biochemical traits of two safflower cultivars, a field experiment was carried out in a split-plot arrangement in a randomized complete block design with three replications. The experimental site (32° 22' N, 48° 07' E), was located at Shahid Chamran University of Ahvaz, with a subtropical hot desert climate. Main plots consisted of four irrigation regimes including; control (irrigation treatments: 80%, 80%, 80%, and 80% of field capacity), mild (irrigation treatments: 60%, 80%, 80%, and 40% of field capacity), moderate (irrigation treatments: 60%, 60%, 60%, and6% of field capacity) and severe (irrigation treatments: 40%, 60%, 60%, and 60% of field capacity), and sub-plots consisted of two sunflower cultivars including; Padideh and Goldasht. Irrigation treatments were applied at stem elongation, branching, flowering, and grain-filling stages.

Deficit irrigation caused a significant reduction in stomatal conductance, photosynthetic rate, chlorophyll index, grain, and oil yield, but increased catalase and peroxidase enzyme activities, carbohydrate and malondialdehyde concentrations. Goldasht cv. with the highest stomatal conductance, photosynthetic rate, chlorophyll index, catalase, and peroxidase enzyme activities, carbohydrates concentrations, and with the lowest malondialdehyde concentrations and oil percentage had the highest economic oil and grain yield and it is recommended in a water-limited condition. The highest levels of antioxidant enzyme activity and lowest malondialdehyde content under water deficit conditions may provide better drought tolerance in this cultivar. The oil yield of both cultivars significantly decreased under moderate and severe heat stress by 31, 43, and 63%, respectively, when compared to the control. Goldasht cv. with a higher grain yield showed a higher oil yield.

Different irrigation regimes applied at different growth stages differently influenced the physiological and biochemical characteristics of safflower cultivars. The developmental stage and severity of water deficiency played an important role in cultivar responses to deficit irrigation regimes. Totally, a moderate deficit regime led to a 43% decrease in oil yield, but by saving about 40% of available water, this treatment is recommended as a suitable strategy for water management to reduce water use in this area.

Sweet pepper is a rich source of essential vitamins and minerals. On the other hand, pepper fruit contains high levels of antioxidants and beneficial substances such as vitamin C, carotenoids and phenolic compounds. It also contains high concentrations of potassium. These compounds has nutritional and antioxidant capacity. Sweet pepper originated from the tropical region, which is sensitive to cold. Therefore, it is necessary to know the defense mechanism of the pepper plant against low temperatures. In this study, the effect of foliar application of salicylic acid and vermicompost on different cultivars of sweet pepper under cold stress has been studied.

The experimental design was a factorial split-plot experiment in a randomized complete block design with three replications in a greenhouse located in Mashhad in the crop year 1396 and 1397. Cultivation was performed hydroponically. The main factor of temperature treatment had two levels [9 ± 2°C (cold stress) and 23 ± 2°C (optimum)] and the sub factor consisting of two sweet pepper cultivars (green, yellow) and Different amounts of Salicylic acid (The dose of 0 μmol salicylic acid was used as control group, 200, 300 μmol) and vermicompost). Sampling of the plants at the end of the growing season, to measure the physiological characteristics and quality were randomly.

The results showed that there was no significant difference between different cultivars in most traits except vitamin C, beta-carotenoids and lycopene. Maximum dry matter (17.2g), TA (13.6 g l-1) in non-stress cold treatment, and soluble solids (5.03 brix),, carbohydrates(174.5 mg g-1), and anti-activity Oxidation (90.3%)  were obtained in cold stress treatment. Damage due to cold stress destroyed the structure of many membrane lipids and resulted in an increase in the amount of antioxidant compounds. Soluble solids are known to be key components in increasing cold resistance. An increase in the amount of soluble solids in winter is part of the plant's adaptation mechanism to cold. The highest yield of fruit per plant(740 g) was obtained in non-cold stress treatment plus salicylic acid 300 μmol. Because salicylic acid in plants improves yield and yield components. Maximum of flavonoids (159.4 mg g-1) was obtained in salicylic acid 200 μmol. Flavonoids are a large group of phenolic compounds in plants that increase their production in environmental stresses by increasing the activity of PAL enzyme. On the other hand, the use of salicylic acid as a stressor causes the production of a wide range of flavonoids. The highest amount of beta-carotene and lycopene were obtained in cold stress treatment, yellow cultivar, and salicylic 300 μmol. Decreased content of carotenoids under stress can be due to oxidation by active oxygen and damage to their structure. Increased photosynthetic pigments under SA treatment indicate the protective effect of this growth regulator on photosynthesis and photosynthetic pigments of stressed plants. Maximum vitamin C was obtained in cold stress treatment (140.7 mg 100 g-1, yellow cultivar (134.7 mg.100g-1), and salicylic 300 μmol (142.52 mg.100 g-1).

According to the results, the of the present study show that use of salicylic acid foliar application modulates the effect of cold stress on the physiological and functional parameters of sweet pepper so that SA can improve cold tolerance by regulating the activities of apoplastic antioxidative enzymes. Therefore, it is suggested that due to sudden changes in temperature due to climate change and the destructive effects of temperature stress, especially cold, on plants, more and more complete research should be done to identify the effects of these stresses and ways to deal with them.

Field Sowthistle (Sonchus arvensis L.) is a plant with high potential medicinal and nutritional values, the medicinal properties of this plant are due to the presence of important phytochemical compounds, especially phenols, and flavonoids. Drought is an important abiotic stress and the most limiting factor for plant growth and production. S. arvensis has valuable secondary metabolites, hence investigation on the responses of this plant against drought stress is of great importance. The purpose of this research was to study the effect of drought stress on morphological characteristics and some phytochemical and biochemical parameters in S. arvensis.

To investigate the effect of drought stress on the morphological, phytochemical, and biochemical characteristics of Field Sowthistle, a pot experiment was carried out as a completely randomized design in three replications. The treatment of drought stress included four levels of 100% (non-stress), 75%, 50%, and 25% of field capacity. The morphological traits studied were shoot and root fresh weight, shoot and root dry weight, plant height, and root length. Also, phytochemical traits include photosynthetic pigments, relative water content, total phenol, total flavonoid, antioxidant capacity with two DPPH and FRAP methods, proline and soluble sugar, and biochemical traits such as activity of antioxidant enzymes catalase, superoxide dismutase, glutathione Peroxidase, ascorbate peroxidase, and total protein were also measured in middle and lower leaves.

The results showed that drought stress had a significant effect on the growth components, the relative content of leaf water, proline, soluble sugar, chlorophyll a and b and total chlorophyll, carotenoid, total phenol, total flavonoid, antioxidant activity of catalase, superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase and inhibition of DPPH radical activity and iron reducing power (FRAP). With the decrease in soil water content, plant height, fresh and dry weight of shoots and roots, relative water content, chlorophyll a and total chlorophyll decrease, and in contrast to root length, chlorophyll b, carotenoid, proline, soluble sugar, total protein, phenol and Total flavonoid, antioxidant enzymes, inhibition of DPPH radical activity and iron reducing power (FRAP) increased. Also, some traits were investigated in the middle and lower leaves, and there was a difference between the above traits between the middle and lower leaves, and the middle leaves contained more of the examined traits.

The results of the present study indicated that drought stress decreases morphological traits except for root length. Also, a higher amount of phytochemical traits were observed in the middle leaves compared to the lower leaves. In general, drought stress caused an increase in the biochemical and phytochemical traits, except for the relative water content, chlorophyll a, and total chlorophyll.

One of the important needs in agricultural planning in order to achieve high yield and optimal quality, especially in the case of medicinal plants, is the evaluation of different methods of plant nutrition. Also, the use of nanofertilizers in agriculture is one of the most beneficial methods of feeding plants. The use of nanofertilizers leads to increasing the efficiency of nutrient consumption, reducing soil toxicity, minimizing the negative effects of excessive fertilizer consumption, and reducing the frequency of fertilizer application. Therefore, considering the medicinal importance of Lallemantia, a research was conducted to investigate the effect of iron nano-fertilizer and zinc nano-fertilizer on some traits of this medicinal plant. Factorial experiment was conducted in a randomized complete block design with three replications at Shahid University of Tehran. The treatments consisted of nano-iron at four levels (0, 1.5, 3 and 4.5 g.l-1) and nano-zinc at four levels (0, 1.5, 3 and 4.5 g.l-1). The source of iron fertilizer used was 9% iron chelate nanofertilizer and the source of zinc fertilizer used was 12% zinc nanofertilizer, which was used as foliar spraying in the above concentrations. In this study, traits such as plant height, number of nuts per plant, leaf dry weight, chlorophyll a, b and carotenoid, total phenol, total flavonoid and antioxidant activity were evaluated. The results showed that the highest plant height (41.3 cm) was obtained using 4.5 g.l-1 of nano-iron fertilizer. Application of 1.5 g.l-1 nano-iron and 3 g.l-1 nano-zinc increased the number of nuts in plant (593.3) and carotenoids in this plant. The highest leaf dry weight (3.6 g per plant) and chlorophyll b (3.7 mg.g-1 fresh weight) concentration were obtained by using 4.5 g.l-1 nano-iron and 4.5 g.l-1 nano-zinc. The concentration of chlorophyll a was also increased by application of 3 g.l-1 nano-iron and 1.5 g.l-1 nano-zinc. The use of nano-iron improved total phenol production and the antioxidant activity. While the lowest amount of antioxidant activity (94.47%) was observed in the control treatment. Finally, the use of 4.5 g.l-1 nano-iron and 3 g.l-1 nano-zinc increased total flavonoid (81.6 mg.g-1) in this plant. In general, the use of higher levels of iron (4.5 g.l-1) and zinc (3 g.l-1 and 4.5 g.l-1) resulted in the best results in the growth and phytochemical characteristics of Lallemantia compared to not using these fertilizers. Therefore, by using appropriate amounts of iron and zinc nano-fertilizers, in addition to reducing fertilizer consumption and reducing environmental pollution, it is possible to improve the quantitative and qualitative characteristics of Lallemantia medicinal plant.

Lactuca undulata is an annual plant belonging to the Asteraceae family. Cichoric acid is one of the most important phytochemical compounds, which is used in the pharmaceutical and food industries. The main objective of the present study was to investigate the effects of drought stress on the morphological and physiological characteristics of Lactuca undulata. For this purpose, 45 days old seedlings were subjected to drought stress at water potential of 0, -0.3, -0.6, -0.9, and -1.2 bar. Polyethylene glycol 4000 was used to create and applydrought stress. The current results showed that by increasing drought stress, the plants gradually withered. The highest level of root and leaf dry and fresh weight, seedling total weight, root and leaf total phenol, leaf total flavonoid, root and leaf soluble sugar, root soluble protein, and root peroxidase enzyme activity were obtained under drought stress with water potential of -0.6 bar. However, the highest amount of root total flavonoid and leaf peroxidase enzyme activity were observed under drought stress with a potential -0.9 bar. The amount of root soluble protein gradually increased with increasing drought stress. But, root and leaf catalase activity showed a significant decrease by increasing drought stress, compared to control. Data from HPLC analysis showed that the highest amount of cichoric acid was obtained after drought stress with water potential of -0.6 and -0.9 bar. In conclusion, the present data showed that drought stress with a potential of -0.6 bar improves the growth factor and the amount of its secondary metabolites.

Taking advantage of the symbiotic relationship between plants and Trichoderma fungi is one of the ways to reduce water stress in plants. The present study was conducted in order to investigate the effect of Trichoderma fungus on the antioxidant properties of the basil medicinal plant (Ocimum basilicum L.) under water stress conditions.

This experiment was carried out in the greenhouse of the Department of Horticulture Sciences of Ahar Faculty of Agriculture and Natural Resources and laboratory studies in the basic and general laboratories of Ahar Faculty of Agriculture and Natural Resources (University of Tabriz) in 2019 in a factorial manner based on a randomized complete block design with three repetitions. The treatments included different levels of water deficit stress, including severe stress (25% of field capacity), moderate stress (50% of field capacity), mild stress (75% of field capacity), and no stress (100% of field capacity). Each pot contained a commercial mushroom species Trichoderma harzianum Na-lac with concentrations of 109 and 106 spores per milliliter as the inoculum.

The results showed that the amount of malondialdehyde, catalase and peroxidase, antioxidant activity and total flavonoid increased with the application of dehydration stress. The concentration of 106 spores per milliliter had a better impact on improving the mentioned indicators. Based on this, Trichoderma fungus proves effective when improving the antioxidant status of plants under drought stress and can prevent the effects of oxidative stress in plants by reducing the oxygen free radicals produced.

The results indicated that the use of Trichoderma mushroom in comparison with the control (without inoculation with the mushroom) can be a suitable tool to improve the physiological traits and antioxidant activities in the conditions drought stress.

This research was carried out in 2022 in order to study the effect of the aqueous extract of different parts of Zygophyllum eurypterum L. on seed germination and seedling growth of wheat and Convolvulus arvensis L. in two separate experiments including the laboratory and the greenhouse conditions, respectively. The experiments were exerted based on a completely randomized design with three replications and randomized complete block design with 4 four replications, respectively. The experimental treatments included water extracts of Zygophyllum eurypterum L in concentrations of 5, 10 and 15% of roots, 5, 10 and 15% of aerial organs (stem and leaves) and control (distilled water). The results showed that with the increase in the concentration of the extracts, the germination and growth traits as well as the total chlorophyll of both plants decreased significantly. In such a way that the highest amount of inhibition was related to 15% arial parts (stem and leaf) extract. Meanwhile, the antioxidant activity of wheat and weed C. arvensis L. increased by increasing the level of Zygophyllum eurypterum extracts. The level of 15% Zygophyllum eurypterum stem and leaf extract in wheat decreased the germination percentage by 63.7% and in C. arvensis L. by 89.2% compared to the control.  Increasing of extract concentration from zero to 15% of arial parts decreased root length decreased by 72.8% in C. arvensis L., and 52.9% in wheat compared to the control. The highest level of antioxidant activity of the weed C. arvensis L. was observed at the levels of 10 and 15% of arial parts extract which were 64 and 73%, respectively. Most of the studied traits of the weed C. arvensis L., such as germination percentage and speed and root length, were more sensitive to the effects of Zygophyllum eurypterum extract than wheat. Examining the results showed that arial parts of Zygophyllum eurypterum were more capable of dealing with germination and seedling growth than the root. Therefore, 15% aqueous extract of Zygophyllum eurypterum stems and leaves can be suggested to reduce the growth and weakening of the weed C. arvensis L.

An imbalanced nutrients status in the nutrient solution, i.e. poor nutrition of the plant, is often responsible for the low quantity and quality of strawberry fruit. The present study was conducted to investigate the effect of different ratios of potassium to magnesium (K/Mg) (T1, 2:1, T2, 4:1, T3, 6:1 and T4, 8:1) on fruit yield and quality of strawberry cv. Albion under hydroponic conditions. Different K/Mg treatments did not have a significant effect on fruit yield and quality attributes such as ascorbic acid and total soluble solids. The highest fruit yield was obtained when plants were exposed to a 4:1 ratio (i.e. T2). Fruit quality attributes such as total anthocyanin, total antioxidant, total phenolic, total flavonoids, total chlorophyll, calcium, Mg, and K concentrations in the leaves and antioxidant enzymes activities were significantly affected by the K/Mg treatments. The highest total phenolic (925 mg/100g FW) and total flavonoids (163 mg/100g FW) were observed when plants grown in the presence of a 4:1 ratio (i.e. T2). Whereas, the highest antioxidant activity (89.2%) was detected in plants exposed to the 8:1 ratio (T4). The highest activity of guaiacol peroxidase (2.88 and 2.78 unit/g FW), ascorbate peroxidase (2.11 unit/g FW), and catalase (2.23 unit/g FW) were observed in T3 and T4, T4, and T4 treatments, respectively. It can be concluded that among the tested treatments, the 4:1 ratio of potassium:magnesium is optimal for the strawberry production.

Due to the role of salicylic acid in resistance to environmental stresses, this study was conducted at Ferdowsi University of Mashhad to evaluate the effect of this compound under saline condition on peppermint. In a pot experiment, the effect of salicylic acid at five concentrations (0, 5, 10, 50, 100 ppm) and salinity (sodium chloride) at three concentrations (0, 75, 125 mM), in a factorial experiment based on Completely Randomized Design with 15 treatments and three replications was evaluated. The simple effect of salinity showed that with increasing salinity, anthocyanin content and antioxidant capacity increased. This was while the number of days to flowering, plant height, number of lateral branches, leaf area, aerial part dry weight, and leaf to stem ratio decreased significantly. The simple effect of salinity also reduced the percentage and yield of essential oil. Significant interaction was observed between different concentrations of salicylic acid and salinity in terms of the effect on the number of lateral branches, dry weight of underground and aerial part, root to shoot ratio and percentage of essential oil. Also, the simple effect of salicylic acid treatment on delay flowering and reduction of plant height was significant. Salicylic acid treatment reduced the percentage of essential oil. However, this treatment was able to prevent a reduction in essential oil yield significantly. Therefore, salicylic acid treatment was able to reduce the possible negative effects of salinity stress.

This experiment works on the physiological, growth, and yield responses of sesame to the application of potassium nano-fertilizers, chitosan, and fulvic acid under drought stress in Semnan Agricultural and Natural Resources Research Center as a factorial split-plot based on randomized complete block design with three replications in 2019. The experimental treatments include drought as the main plot (normal irrigation, irrigation cut offin 70 and 60 BBCH as moderate, and severe stress, respectively) and potassium nano-fertilizer (0, 1.5, and 2.5 per thousand) and foliar application (control, chitosan, fulvic acid, and 50% of chitosan+ fulvic acid) as sub-plots.Application of potassium nano-fertilizer under normal and stress conditions significantly cuts chlorophyll b and total, leaf area index, number of capsules, 1000-seed weight, and oil percentage.The highest grain yield belongs to the application of 1.5 and 2.5 per thousand nano fertilizers, using fulvic acid alone or in combination with 50% chitosan (2516, 2277.5, 2506.6, and 2313.2 kg/ha, respectively). The highest oil content has been in 1.5 and 2.5 per thousand nano fertilizer application under normal irrigation, which has increased 13.2% and 15.4%, respectively. Foliar application of fulvic acid with nano potassium fertilizer (1.5 per thousand) under severe drought stress show the highest activity of antioxidant enzymes catalase, peroxidase, ascorbate peroxidase, and superoxide dismutase. In general, the results show that the application of 1.5 per thousand nano potassium fertilizer and combined foliar application of chitosan and fulvic acid under severe drought by improving physiological traits, manage to modify the adverse effects of drought, increasing growth, yield, and quality indices of sesame.

Introduction

The Crocus genus from the Iridaceae family has more than 70 ornamental species that are very valuable because of the beautiful color of the flower and are used in gardening and green spaces. Among the industrial and export products of Iran, saffron has found a special place as the most valuable agricultural and medical product in the world. The most important compounds in saffron are crocin, picrocrocin, and safranal, which are responsible for color, smell, and taste, respectively. The new approach to producing medicinal plants goes towards increasing the quantity and quality of the effective substance by using sustainable and organic farming methods, so using organic fertilizers in growing medicinal plants becomes necessary to achieve these goals.
 

This research was conducted based on a randomized complete block design with four replications in a saffron farm in Kashmar city and Gorgan University of Agricultural Sciences and Natural Resources Laboratory. Treatments include Kelp seaweed extract in four concentrations (0, 1, 2, 3 mg.l-1), tea compost (0, 200, 300, 400 mg.l-1) and lignin (0, 500, 1000, 1500 mg.l-1). The treatments were carried out at the end of September along with the first irrigation. The research farm was in the sixth year of saffron cultivation. The planting distance was 20×30 cm and 15 corms were planted per square meter. The weight of the corms was 8-10 grams. Sampling from each experimental unit was done randomly. 10 plants were randomly selected from the middle of each plot. The flower was harvested during two weeks and at the beginning of the day, and then the petals were separated from the stigma. After harvesting the flowers and stigmas, they were transferred to a room with a temperature of 21-25 degrees Celsius and relative humidity of 41-52% for drying, using the dry shade method. The measured variables included total phenol, total flavonoids, antioxidant activity, anthocyanin in stigma and petal tissues, and total safranal, total crocin, and total picrocrocin in stigma tissue.

The results showed that the treatments were significant at one percent. The mean comparison showed that the highest amount of stigma total phenol (6.75 mg.g-1) was observed in 3 mg.l-1 of seaweed treatment, and the highest amount of stigma total flavonoids (2.04 mg.g-1) was seen in the interaction of 500 mg.l-1 of lignin, 1 mg.l-1 seaweed, and 200 mg.l-1 tea compost. The highest amount of petal anthocyanin (0.42 mg.g-1) was recorded in 2 mg.l-1 seaweed treatment, the highest percentage of stigma antioxidant capacity (10.47%), and the highest amount of stigma anthocyanin (0.047 mg.g-1) was observed in the control treatment. Based on the results of the mean comparison, no difference was observed between most of the treatments, but the treatment of 1500 mg per liter of lignin (47.24%) increased lignin with a small difference. The lowest amount (24.16%) was related to the 500 mg. l-1 lignin treatment. According to the amount of crocin in the control, it can be concluded that the treatment did not have a great effect on the amount of total crocin in saffron.
 

Finally, it can be concluded that seaweed fertilizers, lignin, and tea compost had a good effect on the saffron plant, and considering the economic importance of this plant, using biological and organic fertilizers as much as possible and replacing them with chemical fertilizers has a positive effect in agriculture. So that, this research had the highest number of flowers and the highest stigma weight in compost tea treatment, which is one of the important factors desired by most farmers. In some treatments, a high level of phenol and anthocyanin in the petals compared to the stigma was seen, which makes pay more attention to the metabolites of the petals, and in some cases, even more advantages than the saffron stigma.

Lentil is usually sowned in late winter and early spring. In this conditions, flowering and seed filling stage usually coincide with late drought stress and high temperature which reduce seed yield. Therefore, supplemental irrigation at the end of the growth season is necessary to overcome this problem. But since in Iran, lentil is mostly cultivated as a rainfed crop in mountain areas and slopes, supplemental irrigation is impossible. By autumn cultivation, plant maturity could be accelerated and higher efficiency of precipitation use, coincidence of growth stages with favorable weather conditions and finally increasing plant height and yield could be achieved. On the other hand, autumn cultivation exposes the plants to sever winter coldness; so, using freezing tolerant cultivars is necessary. The aim of the present study was to identify the role of antioxidants and physiological parameters in improving the cold tolerance of lentil genotypes in controlled conditions.

The study was conducted in autumn and winter of 2018 in research greenhouse of research center for plant sciences, Ferdowsi University of Mashhad, Mashhad, Iran. the experiment was conducted as factorial based on completely randomized design with three replications in controlled conditions. Experimental factors were consisted of 20 lentil genotypes and three freezing temperatures (0, -18 and -20⁰C). Seeds were sown in October and Seedlings were kept in a natural environment for four months and then were transferred to a thermogradiant freezer. Gas exchange parameters (photosynthesis rate, evapotranspiration, substomatal CO2 concentration, stomatal and mesophilic conductance) as well as water use efficiency, relative water content of leaf, photosynthetic pigments, DPPH radical scavenging activity, Anthocyanin, total phenol and soluble carbohydrates were measured before the plants were exposed to freezing temperatures. Survival percentage, plant height, leaf area and plant dry weight were measured four weeks after freezing stress. Lethal temperature 50% of plants according to the survival percentage (LT50su), Reduced temperature 50% of height plant (HT50), Reduced temperature 50% of leaf area (RLAT50) and Reduced temperature 50% of dry matter (RDMT50) were also determined.

Results indicated that in -18⁰C, 14 genotypes had 100% survival while in -20⁰C, all the genotypes were killed. Based on the studied parameters, lentil genotypes were divided in four groups by cluster analysis. Survival percentage in first, second and fourth group was superior compared to the total average. According to the antioxidant activity, metabolites and pigments concentration, plant height, leaf area and dry weight, genotypes in the first (MLC84, MLC407, MLC454) and second (MLC38, MLC303, MLC74, MLC334) groups were relatively superior compared to the other groups. Principal component analysis (PCA) showed that the first component explained 32.77% of changes in water use efficiency, carotenoids, chlorophyll a/b ratio, mesophilic conductance, photosynthesis, survival percentage, plant height, leaf area and dry weight while the second component explained 16.31% of changes in the concentration of chlorophylls a and b, total pigments, soluble carbohydrates, DPPH radical scavenging activity, phenol, anthocyanin, osmotic potential, evapotranspiration and stomatal conduction. Genotypes of MLC74, MLC334, MLC11, MLC84, MLC454 and MLC407 were better in terms of antioxidant capacity and metabolites and MLC303, MLC17, MLC38, MLC286and MLC469 were superior according to the survival percentage and regrowth.

The correlation between concentration of chlorophyll b, carotenoids and photosynthesis rate with survival percentage showed that these traits are suitable indicators for determining cold tolerance of lentil genotypes before exposing to freezing stress. Results of cluster analysis and group mean comparison also indicated the relative superiority of MLC84, MLC407, MLC454 and second MLC38, MLC303, MLC74, MLC334 in most studied parameters. Generally, these genotypes are recommended to be used for complementary studies of freezing tolerance in field conditions in cold regions.

In order to study the effects of pumice (control, 30 and 60 ton ha-1) and different concentrations of Acadian and Estemplex (algae extract) (0, 1.5, 3 and 4.5 ml L-1) on the growth and some physiological characteristics of Coriandrum sativum L., an experiment was conducted as factorial based on a randomized complete block design with three replications at Azarbaijan’s Shahid Madani University, Iran during 2018. The results were suggestive of significant interactions of soil cover and foliar applications on phenolics content, superoxide dismutase activity, Mg, Zn, K and P content of Coriandrum sativum L. The highest concentration of total phenolic compounds was recorded with application of 30 ton ha-1 pumice × 4.5 ml L-1 Acadian and Estemplex. Moreover, the highest concentrations of chlorophyll a and b were recorded at 4.5 ml L-1 Acadian and 3 and 4.5 ml L-1 Estemplex. Application of 3 and 4.5 ml L-1 Estemplex and 3 ml L-1 Acadian led to the greatest total soluble solid contents. The highest amount of plant dry weight were achieved in the presence of 3 and 4.5 ml L-1 Acadian and 1.5 and 3 ml L-1 Estemplex. The highest chlorophyll, flavonoids, protein, and N concentrations and plant dry weight were observed in the presence of 30 ton ha-1 pumice soil cover. Furthermore, 30 and 60 ton ha-1 pumice application reduced IC50 content. In conclusion, application of 30 ton ha-1 pumice and foliar-applied bio-fertilizers, particularly Estemplex (1.5, 3 and 4.5 ml L-1) had positive effects on the growth and physiological traits of Coriandrum sativum L.