Research Article
Postharvest physiology
Davood Hashemabadi; Amirhossein Soleimani; Behzad Kaviani; Nayyereh Naziri Moghaddam
Abstract
IntroductionCut carnation flowers have high economic importance in the floriculture industry. The postharvest life of cut ornamentals, including carnation, is important in determining their quality and consumer preference. High production of ethylene is one of the most important factors that reduce the ...
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IntroductionCut carnation flowers have high economic importance in the floriculture industry. The postharvest life of cut ornamentals, including carnation, is important in determining their quality and consumer preference. High production of ethylene is one of the most important factors that reduce the postharvest life of this flower. High ethylene production causes the aging of some cut flowers. In order to increase the vase life of cut flowers, many researches have been done and various preservative solutions have been introduced, and in some of these solutions, disinfectants have also been used. One of the effective compounds in stopping or reducing ethylene production are alcohols. Ethanol stops ethylene synthesis in cut carnation. Cut carnation is climacteric flower and sensitive to high levels of ethylene. Therefore, the aim of this research was to investigate and compare the effect of different amounts of propanol, butanol and pentanol on the vase life and quality improvement of cut carnation flowers cultivar 'Nelson'.Materials and MethodsIn the present study, propanol, butanol and pentanol were used at the concentrations of 2, 4 and 6% for 24-hour pulse, in order to reduce ethylene production and increase the vase life of cut carnation cultivar 'Nelson' flowers. In February 2020, cut carnation flowers that were harvested at the commercial stage were prepared from a greenhouse in Mahalat city and were immediately transferred to the Postharvest Laboratory, Faculty of Agriculture, Islamic Azad University, Rasht Branch for treatment and evaluation of traits. This experiment was conducted as a completely randomized design in 30 plots. For each treatment, 3 replications and 5 samples for each replication and a total of 150 flower branches were considered. Some traits such as vase life, water absorption, dry matter, petal protein, leaf chlorophyll, ethylene production, fresh weight loss, flower opening index, Brix degree, lipid peroxidation and activity of antioxidant enzymes, peroxidase and superoxide dismutase were measured. To evaluate the vase life of cut flowers, the main criterion is the turning of the petals inward and the apparent wilting of the flowers. Data analysis was done using SAS statistical software and mean comparison based on Duncan's multiple range test.Results and DiscussionThe results of variance analysis of the data showed that the effect of different amounts of propanol, butanol and pentanol application was significant at 5% and 1% probability level on vase life and most of the traits measured in cut carnation flowers. This research revealed that propanol had a more effective role in reducing ethylene production and increasing the vase life than butanol and pentanol. The results showed that the longest vase life (14.11 days) was observed in cut flowers treated with 2% propanol. This treatment also caused the highest amount of water absorption, percentage of dry matter, petal protein and leaf chlorophyll, as well as the lowest amount of ethylene production. The lowest vase life (8.91 days) was observed in control cut flowers. The mean comparison of the different alcohol treatments showed that all treatments of propanol and butanol alcohols in different concentrations increased the absorption of solution by cut flowers compared to the control. Maintaining the water balance in cut flowers is one of the important factors in the vase life of cut flowers. The content of water uptake by cut flowers depends on the hydraulic conductivity of the water channel in the stem and the water potential difference between cut flower tissues and the preservative solution. The least plasma membrane damage was caused in cut flowers treated with 2% propanol. This treatment also caused the highest SOD activity. The short vase life of cut flowers is a global challenge, and efforts are being made to increase their vase life by using appropriate compounds in the vase solution. One of these compounds are alcohols, which have been used by some researchers in order to increase the vase life of various cut flowers. Alcohols are usually toxic for cells in high concentrations. Propanol and butanol in low concentrations inhibited the synthesis of ethylene and therefore increased the vase life of cut carnation flowers. These anti-ethylene compounds prevent the senescence of the petals, which is usually associated with the browning of the petals. Alcohols in optimal concentrations act as a signal and increase the vase life of cut flowers and improve their postharvest quality by reducing lipid peroxidation and inducing the activity of antioxidant enzymes. Similar findings were reported in cut alstroemeria, some carnation cultivars and chrysanthemum flowers.ConclusionThe present study showed the positive effect of disinfectant and antimicrobial compounds on increasing the vase life, some physiologic characters and antioxidants activity. This research revealed that propanol had more effective role in reducing ethylene production and increasing the vase life than butanol and pentanol. The results showed that the longest vase life was observed in cut carnation cv. Nelson flowers treated with 2% propanol.
Research Article
Pomology
afsaneh Salehi; Fatemeh Nekounam; Farhang Razavi
Abstract
IntroductionApple (Malus domestica) belongs to the Rosacea family and is one of the most important fruit trees in temperate regions. Apple fruit is a rich source of vitamins, sugars, organic acids, minerals, fibers, and bioactive compounds and is widely cultivated due to its pleasant taste, aroma, and ...
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IntroductionApple (Malus domestica) belongs to the Rosacea family and is one of the most important fruit trees in temperate regions. Apple fruit is a rich source of vitamins, sugars, organic acids, minerals, fibers, and bioactive compounds and is widely cultivated due to its pleasant taste, aroma, and texture. Due to the rising need for food and fiber per unit of land area, chemical fertilizers are becoming increasingly popular to increase yields from small plots of land. Chemical fertilizers pose major health risks and harm the environment when they are used in excess. Because of this, research in this area is heavily focused on finding and evaluating the efficiency of new products. One such approach is using biostimulants that can enhance the effectiveness of conventional mineral fertilizers. Plant biostimulants contain some nutrients (marine plant extracts, humic acids, amino acids and other natural products such as saponins and compost teas) that stimulate plant growth, even when administered in small amounts. Foliar application of seaweed extracts at 0.2% recorded maximum no. of fruits/tree, fruit weight, and yield/tree in valencia orange.Materials and methodsIn order to investigate the effect of biofertilizers on growth, yield and leaf nutrient contents of apple under climatic conditions of Zanjan, the experiment was carried out in a completely randomized block design with three replicates in 2023. Different concentration of seaweed (Alg; 0.075 and 0.15%), amino acid (GF Amino; 0.1 and 0.2%), humic acid (HA; 0.3%), commercial fertilizer Homarang, (Homa fert; 0.5%), combined chemical fertilizer (nitrogen, zinc and boron (Combinate fert; 1% urea, 0.3% zinc chelate and 0.1% boric acid)) and distilled water as a control were sprayed on the trees at 40 days after full bloom stage until runoff using a mechanical mist sprayer, and repeated three times with an 30 days interval until the physiological ripening of fruits. The experiment was carried out on 10-year-old Red Delicious apple trees grafted on M9 rootstocks. Shoot length, chlorophyll index, fruit drop percentage, yield efficiency, leaf area, leaf dry matter, leaf macro and micro nutrient were measured. The analysis of variance (ANOVA) and least significant difference test (P≤ 0.05) used to compare means within each sampling date. The Statistical analysis and standard error calculation were carried out using SAS software (V. 9.3).Results and DiscussionThe results showed that the foliar application of bio and chemical fertilizers significantly increased growth and fruit yield. So that, the highest increase in shoot length (39%) and leaf area (74.30%) compared to the control was obtained with application of seaweed 0.075%. Also, seaweed 0.15%, amino acid 0.2%, humic acid and amino acid 0.1% caused a significant increase in leaf area (42.02, 35.57, 22.27 and 16.20%, respectively) compared to the control. Foliar spray of seaweed, amino acid and chemical fertilizer increased chlorophyll index. The highest increase in chlorophyll index (50%) compared to the control was obtained with application of combined chemical fertilizer at 130 days after full bloom. These results are in agreement with the outcomes of other experiments conducted with seaweed on apple and on other crops such as grapevine. Therefore, this represents a further evidence of a possible role of seaweed extracts in the reduction of chlorophyll degradation and in delaying leaf senescence. The highest amount of nitrogen (1.66%), potassium (1.03%) zinc (150 mg g-1DW) and boron (82.5 mg g-1DW) and the lowest amount of phosphorus (0.44%) were obtained with application of combined chemical fertilizer. The highest value of iron was observed in leaf of trees treated with seaweed 0.15%, humic acid and commercial biofertilizer. Based on the results, it was observed that the amino acid, seaweed and combined chemical fertilizer have the greatest effect in reducing fruit drop (36.97, 33.37, 29.07%, respectively) compared to control) and increasing yield efficiency (respectively 2.75, 2.73 and 2.8 compared to control with 0.22 fruits No. cm-2 SCSA). These results partially are in agreement with another research performed on apple, where the use of a similar seaweed extract (Ascophyllum nodosum) was found able to induce a higher final yield. The hormonal components found in the extracts, particularly cytokinins, are assumed to be responsible for the increased yield in plants treated with seaweed. Previous studies mentioned that the application of biological fertilizers alone or in combination with the mineral fertilizers had positive influences on the leaf plate area, mean fruit weight and fruit chemical composition. ConclusionsAccording to the results of this research, the use of biofertilizers, especially seaweed (0.15%) and amino acid (0.1%), are suitable and nature-friendly substitutes for chemical fertilizers and can play a significant role in increasing growth indices and yield of apples.
Research Article
Medicinal Plants
Ghasem Esmaeili; Majid Azizi; Hossein Arouiee; Jamil Vaezi
Abstract
Introduction: The genus Salvia L. (Lamiaceae) is one of the most interesting plant genera with a variety of annual, biennial, perennial and shrub forms. According to recent reports, there are 61 species of Salvia genus in Iran, among which 18 species are endemic. The use of Salvia species dates back ...
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Introduction: The genus Salvia L. (Lamiaceae) is one of the most interesting plant genera with a variety of annual, biennial, perennial and shrub forms. According to recent reports, there are 61 species of Salvia genus in Iran, among which 18 species are endemic. The use of Salvia species dates back to ancient times, and they are now being used for different purposes such as antimicrobial, anthelmintic, anti-inflammatory, tonic, carminative, digestive, Alzheimer’s disease, antispasmodic as well as for traditional medicines and food industries. Compared to crop plants, the breeding programs of medicinal plants are still in nascent stages due to high biological and biochemical variations. Since breeding programs, especially in medicinal plants, are expensive, suitable mating can help reduce the costs of breeding programs. Understanding the flowering biology, reproductive systems and pollination mechanism is essential to management and protection of ecosystems and mating programs. Despite the high diversity of Salvia genus in Iran, there is a paucity of studies on reproductive biology.Materials and methods: seeds of seven Salvia species including S. virgata (with four accessions), S. frigida, S. nemorosa, S. atropatana, S. macrosiphon, S. sclarea, and S. syriaca were collected from different geographical regions. The seeds were treated by various methods such as washing, cold treatment (stratification), scarification (sand and sulfuric acid), Gibberellic acid (GA3) and KNO3 to enhance germination. The seedlings were produced at the greenhouse and after growing as high as 15 cm or reaching the10-leaf stage, the seedlings were transferred to the farm. Plants phenology and flowering duration were recorded in the second year. Furthermore, some flower characteristics and pollinator were monitored. The Various pollination treatments were designed to investigate the breeding system of Salvia species including open pollination, spontaneous autogamy, geitonogamy, xenogamy, apomixis, and control. The self-incompatibility index (ISI) was calculated for each species in different pollination treatment.Results and discussion: The germination study exhibited that washing seeds for 24 h and applying 250 ppm GA3 exerted the highest effect on seed germination. The seedlings in early growth stages required medium to high porosity (high permeability to water and air) like natural habitat, but they were sensitive to dry and high EC at these stages. The phenology studies were shown Salvia virgata (all accessions) and S. nemorosa flowered three months after cultivation and other species flowered in the second year. The results showed that all species had long flowering periods ranging from 15 (S. atropatana) to 41 days (S. virgata). Increased flowering period led to the enhancement of flower over-lapping and the sharing of the pollen among different plants or species. Two species including S. atropatana and S. syriaca had heterostyly flowers (long-styled morph). The staminal-lever-mechanism was observed in all species. The results of manual pollination indicated that open pollination provided the best treatment with the highest average of seed set (73.63%) in all species. Salvia virgata (A1) with a seed set of 90.3% was the best species, and S. syriaca with a seed set of 51.5% demonstrated the poorest performance in open pollination system. The seed set in the xenogamy treatment of different species and accessions was in the range of 10.2 (S. syriaca) to 32.5% (S. frigida). It was observed that seed set among different species in geitonogamy and spontaneous autogamy varied widely from 2.60 - 17.30% and 2.98 - 12.18%, respectively. In treatments with a wide variety of pollen sources, the fruit set was higher, indicating that the pollen limitation triggered low seed set.Conclusion: Salvia species in the present study have a high potential for cultivation as medicinal and ornamental due to suitable adaptability and long flowering period. Salvia species were relatively self-incompatible that intention to the out-crossing and breeders can use in breeding programs as a valuable characteristic. The self-incompatible and specific structure in flower and pollination are the reasons for the diversity of this taxa.
Research Article
Medicinal Plants
Somaye Amini; Maryam Shamshirkesh shahri
Abstract
Introduction: Invasion of weeds is one of the major factors in the reduction of yield of agricultural crops in the field conditions. Use of allelopathic plants is one of the methods of weeds control. So far, numerous laboratory and farm methods have been designed to evaluate the allelopathy in various ...
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Introduction: Invasion of weeds is one of the major factors in the reduction of yield of agricultural crops in the field conditions. Use of allelopathic plants is one of the methods of weeds control. So far, numerous laboratory and farm methods have been designed to evaluate the allelopathy in various plants. Recently, there have been advances in allelopathy knowledge through the advent of innovative techniques and suitable bioassays. Researchers have shown that numerous problems could be solved in allelopathy investigations by the implementation of such techniques. The old methods have been replaced with new methods such as the Sandwich method by which allelopathic properties of various plants could be evaluated during the shortest time and using the minimum amount of plant sample. Materials and methods: Considering that there is significant evidence of the presence of allelopathic compounds in invasive weeds as well as medicinal plants, therefore, in the current research, the main focus was on these two groups of plants for the selection. In this research, the allelopathic activity of 57 plant species (60 samples including leaf, stem, seed, rhizome, flower, gum) of 18 families was investigated using the Sandwich method. In this method, plant samples were first dried at 40 degrees Celsius and then weighed in three replicates with amounts of 10 and 50 mg. Special containers with 6 well were used for cultivation. The diameter of each well was 3 cm. In one row of the wells, 10 mg and 50 mg of plant sample powder were placed in the other row. Then 5 ml of 0.5% agar solution was added to the samples and after the agar cooled and coagulated, another 5 ml of agar solution was added to each well. In this way, the plant sample was placed between two layers of agar. Then, in each well, 5 seeds of lettuce (Lactuca sativa) variety Great Lakes 366 were planted vertically on the agar surface. This variety of lettuce has been selected as an indicator due to its high sensitivity to metabolites. Then the containers were sealed and placed in an incubator with a temperature of 25 degrees Celsius in the dark conditions. After 3 days, the percentage of seed germination was checked by measuring the length of lettuce radicle and hypocotyl. To make it easier to compare plants, data clustering was performed using Minitab software.Results and discusion: Using this method, 59 plant samples were placed into 10 distinct clusters. The similarity of plants in each cluster was 85%. The findings revealed that the leaf residues of Anethum graveolens and a Cynara cardunculus clustered together based on their allelopathic activity, demonstrating the most significant growth-inhibitory effect at a concentration of 10 mg of the plant sample. The average percentage of inhibition of radicle and hypocotyl growth of lettuce seedlings caused by these two plants was reported to be 94.95 and 87.65 percent, respectively. Also, 13 plants including leaves of Chenopodium album, Prangos ferulacea, Lepidium draba, Petroselinum crispum, Dianthus barbatus, Convolvulus arvensis, Narcissus tazetta, Heracleum persicum, Onosma dichroantha, Stellaria media, Brassica cretica, Ipomoea purpurea and Apium graveolense Seeds were placed in one cluster. This group also had significant growth inhibitory effects. Although their inhibitory effects were always less than Anethum graveolens and a Cynara cardunculus. The average percentage of radicle and hypocotyl growth inhibition in these plants with 10 mg of dry plant sample was 79.76 and 62.27, respectively. This study demonstrated that both the leaf residue of Hypericum perforatum and Hypericum scabrum significantly enhanced the growth of lettuce seedlings. Even minimal amounts (10 mg of the dried plant sample) resulted in a remarkable increase in radicle growth by 14.65% and hypocotyl growth by 45.15%. Additionally, at a mount of 50 mg, Pistacia lentiscus gum demonstrated exceptional efficacy, enhancing radicle growth by an impressive 90%. Among the plants studied in this study, Cupressus sempervirens leaf residues had an inhibitory effect on radicle growth but stimulated hypocotyl growth. Centaurea behen leaf residues only produced a growth-stimulating effect (43.3%) on hypocotyl growth at amount of 10 mg, and in other cases, they showed allelopathic effects in the form of growth inhibition.Conclusion: This study confirms the reliability of the sandwich method for identifying allelopathic plants and assessing their properties. It efficiently evaluates a variety of plants with fewer samples and time. The results suggest that plant residues could be used in organic farming to control weeds. Further research is necessary to identify the specific allelopathic compounds involved.Acknowledgement: The authors of this article would like to thank Mr. Mohammad Reza Joharchi, a faculty member of the Herbarium of Ferdowsi University of Mashhad, for his sincere cooperation in identifying the plants used in this study from a botanical perspective, confirming the Persian names, and matching them with scientific names.
Research Article
Medicinal Plants
ELAHE GHAFOOREAN HOZORI ISFAHAN; Majid Azizi
Abstract
IntroductionMedicinal plant are very importnat in health care for today societies and the need for it is increasing. Greenhouse production of transplants face different limitations including light. LED lights are introduced for solving the problem. An LED lamp or LED light bulb is ...
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IntroductionMedicinal plant are very importnat in health care for today societies and the need for it is increasing. Greenhouse production of transplants face different limitations including light. LED lights are introduced for solving the problem. An LED lamp or LED light bulb is an electric light for use in light fixtures that produces light using one or more light-emitting diodes (LEDs). LED lamps have a lifespan many times longer than equivalent incandescent lamps, and are significantly more efficient than most fluorescent lamps. Experiments revealed surprising performance and production of vegetables and ornamental plants under LED light sources. Many plant species have been assessed in greenhouse trials to make sure that the quality of biomass and biochemical ingredients of such plants is at least comparable with those grown in field conditions. Plant performance of mint, basil, lentil, lettuce, cabbage, parsley and carrot was measured by assessing both the health and vigor of the plants and the success of the LEDs in promoting growth. Also noticed was profuse flowering of select ornamentals including primula, marigold and stock.Materials and Methods In order to investigate the effect of supplementary LED light on the growth parameters and the amount of active ingredient in Hypericum perforatum L. “Topaz” cultivar, a research was conducted in two independent experiments. The research was set up in a completely randomized design with three replications. The first experiment experienced the extended of day length with 4 hours at the end of the day (started from sunrise to sunset). LED treatments were started at 10 cm height of the transplants. The second experiment examined the light types. In this order the considered treatments consisted of four levels of red light (L1), blue light (L2), combination of 67% red light and 33% blue light (L3), white (L4), 100% natural light(L5), with an intensity equal to (200 fc). Measurement of traits in the first experiment was carried out at flowering stage. Aerial part fresh and dry weights, number of black nodes, days to flowering, leaf area, total chlorophyll, antioxidant activity, total phenol, plant height and hypericine percentage were determined within both experiments.Results and Discussion The results showed that the simple effect of supplementary combination red and blue light (started from sunrise to sunset) on growth, morphological, physiological and biochemical traits was significant at 1% probability level. The highest plant dry weight was detected in L3 in the first and second harvests respectively (8.63 g, 66.29 g). Also, the highest percentage of Hypericine in the first harvest was obtained for L3 (0.17%). Measurement of the traits in the second experiment was carried out at the seedling stage. Results showed that the simple effect of supplementary combination light (sun exposure and day length increased for 4 hours) had a significant effect (p≤0.01) on growth rate, physiological, morphological and biochemical properties. So that the lowest number of days to flowering (early flowering) was obtained from L3 treatment (101 day), and the highest percentage of Hypericin was related to L3 treatment (0.156%). Black node numbers and total phenol content were increased by 27 and 53 % with supplementary light treatments respectively. Antioxidant activity was also raised and enhanced from 33 % to 75 % with LED light application. Plant height and total chlorophyll content were enhanced from 13 to 23 cm and 12 to 22 mg/g FW as well. Regarding studied traits and the obtained results of the both experiments, the positive effect of applying LED light, red and blue on the growth and biochemical properties, especially the Hypericine percentage and yield of St. John’s wort is quite evident.Different reactions were observed in response to supplementary light treatments for St. John’s wort. Most of the enhancements observed were mainly due to optimized photosynthesis activities and more metabolic production processes.Conclusions Regarding studied traits and the obtained results of the both experiments, the positive effect of applying LED light, red and blue on the growth and biochemical properties, especially the Hypericine percentage and yield of St. John’s wort is quite evident. It seems that a combination of red and blue light could be suggested for solving the light limitations and increasing the medicinal plant production for future.Keywords: Supplementry light, light quality, Hypericum perforatum, Hypericine
Research Article
Medicinal Plants
Fatemeh Esmaeili; Hasan Bayat; Hossein Nastari Nasrabadi; Mohammad Hossein Aminifard
Abstract
IntroductionLight plays a fundamental role in plant growth and development, significantly influencing photosynthesis and overall plant yield. Various light characteristics, including intensity, quality, and duration, have critical effects on plant biological processes. The light spectrum can significantly ...
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IntroductionLight plays a fundamental role in plant growth and development, significantly influencing photosynthesis and overall plant yield. Various light characteristics, including intensity, quality, and duration, have critical effects on plant biological processes. The light spectrum can significantly impact plant metabolism throughout the growth period. The use of LED light not only provides the necessary wavelengths but also reduces energy loss and allows precise control over the photosynthetic photon flux. LED lighting can be utilized to optimize plant growth and yield in greenhouse and growth chamber environments. Blue and red light are the primary wavelengths involved in carbon dioxide fixation and photosynthesis, exerting a significant influence on plant growth (Cosgrove, 1981; Kasajima et al., 2008.( Hyssopus officinalis, a perennial plant belonging to the Lamiaceae family, is well known for its antimicrobial, antioxidant, and anti-inflammatory properties. This study evaluates LED light as an alternative to natural sunlight in controlled environments. Previous research has shown that changes in light quality can significantly affect growth parameters such as plant height, stem length, leaf length and width, leaf area, and fresh and dry biomass. Optimizing light conditions can enhance plant production in closed environments, offering economic and scientific potential for the cultivation of medicinal plants. The objective of this research was to investigate the effects of different LED light spectra on the growth, physiological, and morphological characteristics of Hyssopus officinalis.Materials and MethodsTo investigate the growth and physiological characteristics of Hyssopus officinalis, an experiment was conducted using a completely randomized design with three replications and six LED light treatments. The seeds were sourced from Glass Garden Company. The growing medium consisted of a mixture of 40% cocopeat, 40% perlite, and 20% vermiculite to provide optimal conditions for plant growth. In the growth chamber, the light treatments included white (control), 100% red, 100% blue, red:blue (70:30), red:blue (30:70), and red:blue (50:50). White light served as the control treatment. The LED lamps used in this experiment were 24-watt wall washers with different light spectra, covering wavelengths from 400 to 700 nm. The light intensity was set at 250 ± 10 μmol photons m⁻² s⁻¹. The photoperiod was maintained at 16 hours of light and 8 hours of darkness, with day and night temperatures of 25°C and 20°C, respectively. Following germination, the plants were irrigated daily with a half-strength Hoagland nutrient solution. Once the plants reached the four-leaf stage, they were supplied with a full-strength Hoagland solution every other day (20 g in 10 liters of distilled water) at a rate of 100 cc per pot .After five months, morphological and physiological parameters were evaluated. Measurements included stem, root, and leaf length; leaf width; leaf area; root volume; internode length; number of lateral branches; fresh and dry weight of roots, stems, and leaves; total fresh and dry weight of the plant; and chlorophyll a, chlorophyll b, total chlorophyll, Essent oil yield content .Data analysis was performed using SAS statistical software, and mean comparisons were conducted using the LSD test at a significance level of )p ≤ 0.05).Results and DiscussionThe results showed that different light spectra had a significant effect on the growth and physiological characteristics of the hyssop plant at the 5% and 1% probability levels. The highest fresh and dry weight of shoot, root, and total plant was recorded under red light. The highest amounts of chlorophyll a (1.11 mg/g fresh weight) and chlorophyll b (1.89 mg/g fresh weight) were observed in plants grown under red: blue (70:30) and red: blue (30:70) light combinations, respectively. The highest (1.10 mg/g fresh weight) and lowest (1.01 mg/g fresh weight) of carotenoid content were found under the red: blue (70:30) and the red: blue (30:70) light combinations, respectively. The maximum essential oil (1.71%) recorded under red: blue (30:70) combination. The highest and the lowest antioxidant activity levels were recorded in the red: blue (50:50) and control light treatments, respectively.ConclusionThe results showed that different light spectra significantly influenced the morphological and physiological characteristics of Hyssopus officinalis. Red light increased morphological and growth characteristics properties. These findings suggested that optimizing light spectra can significantly affected the growth and development of Hyssopus officinalis, and further studies could explore these mechanisms. The results of this study showed that use of modern agricultural methods with artificial lighting systems improved the growth and physiological indices of Hyssop (Hyssopus officinalis). The application of 100% red light and 30:70 red-blue light combinations is recommended.
Research Article
Growing vegetables
Afsane Farahmandi; Bijan Haghighati; Babak Madani
Abstract
Vegetables are among the most important agricultural products in Iran, holding significant importance in terms of production and consumption. These products, in addition to meeting nutritional needs, play a crucial role in public health. Due to their high nutritional value, fiber content, and antioxidant ...
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Vegetables are among the most important agricultural products in Iran, holding significant importance in terms of production and consumption. These products, in addition to meeting nutritional needs, play a crucial role in public health. Due to their high nutritional value, fiber content, and antioxidant compounds, the consumption of vegetables has always been emphasized by nutritionists and is increasing. In healthy diets, regular consumption of vegetables is recommended as a rich source of vitamins, minerals, and antioxidants. However, one of the main challenges associated with vegetable consumption is the nitrate content, which can have adverse effects on human health.Nitrate is a natural compound in plants that is primarily absorbed from the soil and accumulates in plant tissues. Under normal conditions, small amounts of nitrate are essential for plant growth, but excessive accumulation can pose serious health risks. Overconsumption of nitrate may lead to diseases such as methemoglobinemia (blue baby syndrome), which is particularly dangerous for infants. Additionally, some studies have suggested that excessive nitrate intake may be linked to an increased risk of certain cancers. Therefore, controlling nitrate levels in agricultural products and finding effective methods to reduce its accumulation in plants is of great importance.Selenium, due to its effects on plant growth and its role in antioxidant systems, is an essential micronutrient for human health. This element plays a crucial role in boosting the immune system, preventing oxidative stress, and reducing the risk of chronic diseases. In plants, selenium acts as a growth regulator and influences various metabolic processes. Numerous studies have shown that selenium can reduce nitrate accumulation in plants and improve nitrogen uptake and utilization efficiency. This highlights the significance of investigating the effects of selenium on nitrogen metabolism and nitrate levels in plants.In this study, the effect of sodium selenite and calcium nitrate foliar application on certain growth characteristics, biochemical properties, nitrate and selenium content, and nitrate reductase enzyme activity in spinach was investigated. Spinach is one of the most widely consumed leafy vegetables due to its high iron, vitamin C, and antioxidant compound content, making it highly nutritious. The treatments included foliar application of calcium nitrate (5, 10, and 20 mM), sodium selenite (0.5, 1, and 1.5 mM), and a control (distilled water). Foliar application is a commonly used method in plant nutrition management due to its rapid absorption and direct impact on plant physiology. After the growth stage (8–10 leaf stage), growth indices, biochemical compounds, nitrate and selenium content, and nitrate reductase activity were measured.The results indicated that foliar application of sodium selenite and calcium nitrate significantly affected chlorophyll a, b, total chlorophyll, and carotenoid content. An increase in chlorophyll content suggests improved photosynthesis and light absorption efficiency in plants. Additionally, the highest total phenol content, antioxidant activity, and nitrate reductase activity were observed in the 20 mM calcium nitrate and 1.5 mM sodium selenite treatment. Phenolic and antioxidant compounds play a crucial role in protecting plant cells against environmental stresses and pathogens. Therefore, increased antioxidant activity in plants can also enhance the nutritional quality and shelf life of the final product.The highest nitrate content was observed in the control, while the highest selenium concentration was found in the 1.5 mM sodium selenite treatment. These findings suggest that selenium application can reduce nitrate levels and improve the nutritional quality of spinach. Since excessive nitrate accumulation in leafy vegetables can endanger consumer health, adopting effective methods to reduce this compound in plants is essential. The use of regulatory elements such as selenium provides a practical solution for mitigating this issue.The results of this study demonstrated that sodium selenite foliar application reduced nitrate accumulation, increased nitrate reductase enzyme activity, and enhanced selenium concentration in spinach. Nitrate reductase is a key enzyme in nitrogen metabolism, responsible for reducing nitrate to nitrite and facilitating its utilization in essential plant structures. Increased activity of this enzyme indicates improved nitrogen uptake and utilization, which can lead to better growth and higher yield.Therefore, foliar application of 1.5 mM sodium selenite in spinach is recommended to achieve maximum antioxidant compounds, increased selenium concentration, and minimal nitrate accumulation. This method not only improves the nutritional quality of agricultural products but also serves as a sustainable approach to reducing health risks associated with nitrate accumulation in vegetables. Furthermore, the application of selenium can enhance the plant’s defense mechanisms and increase its resistance to environmental stresses.
Research Article
Breeding and Biotechnology of Plant and Flower
Elham Gohari; Hossein Torabzadeh; Saeed Alvandy; Morteza Heidarimozaffar
Abstract
IntroductionWalnut is one of the most important economic products of Iran and the world. Among the climatic factors effective in choosing the right place for planting walnut trees, we can mention the spring cold. Most of the walnut planting areas in Iran are mostly in the areas that have damaging colds ...
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IntroductionWalnut is one of the most important economic products of Iran and the world. Among the climatic factors effective in choosing the right place for planting walnut trees, we can mention the spring cold. Most of the walnut planting areas in Iran are mostly in the areas that have damaging colds in spring. The largest area under walnut cultivation in Iran is concentrated in the mountain hills and heights of the Zagros and Alborz mountain ranges. Every year, walnut production is limited by spring frosts, which, in addition to reducing production, can also damage sensitive plant tissues. Frost damage is one of the cases that are subject to compensation from the Agricultural Insurance Fund. Due to the high economic value of this product, an accurate, fast and low-cost estimation is necessary to evaluate the damages caused by this phenomenon on the walnut product. In this regard, in order to plan for the accurate calculation of the amount of compensation to the insurer, the insurer needs comprehensive information, so that it can estimate the performance losses caused by various factors. Remote sensing methods for frost monitoring using vegetation indicators are very efficient and effective. Therefore, this research examines spring frost damage by providing a quantitative index. Materials and methodsIn this research, frost damage of the Agricultural Insurance Fund was used for walnut trees. The damage assessment was presented over a period of nine years.Vegetation index values extracted from OLI, ETM+, MSI sensors have been used to overcome adverse weather conditions. Each of the vegetation indicators has different noises such as light changes during the day, wind speed, temperature, sun angle, etc. . In order to smooth the indices, SG filter was used. This filter was calculated with window size 11 and degree 2. In this filter, choosing the window size and degree is very important, because the small window size and degree cause noise to remain in the data, and if the window size and degree are chosen large, they lead to the loss of information related to vegetation indices. Meanwhile, choosing the reference year for comparison with other years was of particular importance. According to the consistency of the filtered indicators and the damages reported by the Agricultural Insurance Fund, the reference year was determined. The SFDI index was presented in each year using the filtered values of the relevant vegetation indices, between the reference year and other years. In general, the enclosed area of the two curves between the intersection points at the beginning and the end has indicated the values of the SFDI index in each year.Results and DiscussionThe relationship between SFDI index and damages was done through 2nd degree polynomial model and linear regression. The status of the SFDI index compared to the estimates of the agricultural insurance fund for all villages was investigated through two polynomial models of the 2nd degree and linear regression. The accuracy of the regression model was evaluated with criteria such as: r, RMSE, P-value. The value of r indicates how well a model can predict the value of the dependent variable in percentage terms. The higher the value of r, the better the model. RMSE values indicate how well a regression model can predict the value of the variable. The quantity P-value shows the significance of two independent and dependent variables, and values less than 5% indicate the existence of a relationship between two variables at a significant level of 95%. It is useful to calculate all three quantities for a given model, as each measure provides useful information. Spring frost damage index based on NDVI vegetation index with correlation coefficients of r = 0.927 and r = 0.823 were able to estimate the damage. Finally, the maps of spatial distribution and spring frost damage showed a good fit with the damage reported by the Agricultural Insurance Fund. ConclusionThe SFDI index has provided a positive effect in the assessment of frost damage. Also, the results of the spatial distribution of the SFDI index have shown the effectiveness of this index, in such a way that with the increase of this index, the frost damage percentage of the agricultural insurance fund has also increased. The results showed that this index evaluated the effects of spring frost effectively and quickly and showed a good correlation with the decrease in crop yield.
Research Article
Pomology
Seyed Asghar mousavi; Akram Vatankhah; Ali Imani
Abstract
IntroductionAlmond is a commercial and important nut fruit known as Prunus dulcis, a species of Prunus of the Rosaceae family. The nutritional value of almonds as well as the presence of oil, protein, fiber, minerals and biologically active compounds have made almonds Nutrionally, industrially and medicinally ...
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IntroductionAlmond is a commercial and important nut fruit known as Prunus dulcis, a species of Prunus of the Rosaceae family. The nutritional value of almonds as well as the presence of oil, protein, fiber, minerals and biologically active compounds have made almonds Nutrionally, industrially and medicinally important. In most native orchards of Iran, almonds are cultivated through seeds, which has increased the genetic diversity of this plant. The introduction and production of superior cultivars depends on the careful selection of plants, which requires knowledge of the cultivars and their diversity. Cross-pollination in almond increases genetic diversity in cultivated species. Creating a orchard by selecting grafted genotypes on suitable rootstocks for sustainable cultivation of almonds is particularly important (Babadai et al., 2017). The aim of this research is to evaluate the phenotypic diversity of 44 promising genotypes that were grafted on GF677 rootstock, using the vegetative, quantitative and qualitative characteristics of nuts and kernels in order to select superior genotypes. A great diversity was observed in the morphological and pomological characteristics of 60 almond genotypes by Ardjmand et al. (2014). Many researches (Mousavi et al., 2010; Asgari and Khadivi 2021; Heidari et al., 2022; Beigi and Khadivi, 2023) have been conducted on the selection of superior cultivars by examining the morphological, nut and kernel characteristics.Materials and methods:In this research, 44 promising almond cultivars and genotypes on GF677 rootstock were investigated in terms of various vegetative traits, nut and kernel characteristics. Experiment on 44 almond genotypes prepared from Karaj and grafted on GF677 rootstock, in March to September 2024 in the form of randomized complete block design in three replications at the almond research station in Saman region affiliated to the Chaharmahal and Bakhtiari Agricultural and Natural Resources Research and Education Center was conducted on 5-year-old trees. Vegetative traits of tree height, canopy length, canopy width, and branch length were measured by meter in the garden, and rootstock diameter, scion diameter, and branch diameter were measured in the garden with calipers. In order to measure nut and kernel traits, 100 fruits were harvested from each of the cultivars and genotypes, and their green shell was separated and dried. Measurement of traits such as length, width, diameter of nut and kernel was done by digital caliper and weight of nut and kernel was measured by digital scale with accuracy of 0.01. Coding of some traits was done based on almond descriptor (Gülcan, 1985) with some changes. The data obtained from the experiment were analyzed using SAS software (version 3.1.9). To compare the means, LSD least significant difference test was used at the 5% probability level.Results and DiscussionThe results of analysis of variance for the evaluation of vegetative traits showed that there was a significant difference between promising cultivars and genotypes in terms of tree height, canopy length and canopy width, one-year branch length, canopy length-to- canopy width ratio, and canopy height-to- canopy length ratio at the 1% probability level. The results of the analysis of variance showed that between all cultivars and genotypes grafted on GF677 rootstock in terms of length, width, diameter and weight of nuts, length, width, weight and diameter of kernel, shell thickness, double kernel, percentage of blank kernel, kernel color and shrinkage of kernel, shell hardness, suture opening of the shell, percentage of kernel, kernel width/kernel length ratio, kernel thickness/kernel length ratio, kernel thickness/kernel width ratio and kernel weight/nut weight ratio have significant differences. Based on the obtained results, the genotypes 4-4, TS-11, H, 2-3-2, 2-0-4 according to the valuable and commercial properties of almonds, including yield, kernel percentage, shell hardness, percentage of blank kernel, kernel weight, suture opening of the shell, double kernel, shell thickness, kernel color and most importantly late flower were genotypes with relative superiority in terms of nut and kernel traits. According to the results, the 4-4 genotype grafted on the GF677 rootstock with yield of 750 gr, 51% kernel percentage , hard shell, excellent seal suture opening of the shell, very light kernel color, late flowering, flowering on spurs and one year old shoots, the low of double kernel and low percentage of blank kernel seems to be one of the relatively good genotypes for Chaharmahal and Bakhtiari region. In the study of Mousavi et al., 2010, by examining the quantitative and qualitative characteristics of 55 varieties and genotypes of almonds, reported that all quantitative and qualitative traits in the genotypes have significant differences, which is in line with the results of this research. ConclusionBased on the results of this study, significant variation in morphology, phenology, and pomology was observed among 44 promising genotypes grafted onto GF677 rootstock. This variation is of great importance in selecting superior cultivars that are adapted to environmental conditions, as well as in selecting high-yielding genotypes. Chaharmahal and Bakhtiari province, with its specific climatic conditions, requires varieties that are adapted to these conditions. The climatic conditions of this region include hot and dry summers and cold winters, so varieties that are resistant to cold and drought should be selected, especially varieties whose flowering date is such that they are safe from the risk of spring frost. Based on the obtained results, the genotypes 4-4, TS-11, H, 2-3-2, 2-0-4 according to the valuable and commercial properties of almonds, including yield, kernel percentage, shell hardness, percentage of blank kernel, kernel weight, suture opening of the shell, double kernel, shell thickness, kernel color and most importantly late flower were genotypes with relative superiority in terms of nut and kernel traits. According to the results, the 4-4 genotype grafted on the GF677 rootstock with yield of 750 gr, 51% kernel percentage, hard shell, excellent seal suture opening of the shell, very light kernel color, late flowering, flowering on spurs and one year old shoots, the low of double kernel and low percentage of blank kernel seems to be one of the relatively good genotypes for Chaharmahal and Bakhtiari region.
Research Article
Medicinal Plants
Roghayeh Nabipour Sanjbod; Esmaeil Chamani; Younes Pourbeyrami Hir
Abstract
1. Title: The improvement of germination, growth, and biochemical indices of Echium amoenum Fisch & Mey. under different light qualities2. Introduction: Medicinal plants, as a valuable source of herbal medicines and bioactive compounds, are rapidly declining due to uncontrolled collection from nature. ...
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1. Title: The improvement of germination, growth, and biochemical indices of Echium amoenum Fisch & Mey. under different light qualities2. Introduction: Medicinal plants, as a valuable source of herbal medicines and bioactive compounds, are rapidly declining due to uncontrolled collection from nature. Echium amoenum Fisch & Mey. belongs to the Boraginaceae family and has a special place in Iranian traditional medicine. This plant is native to Iran and has been used to treat many infectious and inflammatory diseases, as well as modern diseases related to stress and anxiety, for many years. However, low germination percentage and uneven germination are some of the obstacles to the growth and propagation of this valuable medicinal plant. Recently, it has been reported that LED light sources have significantly increased the germination of some medicinal species. The response of plants to light spectra depends on the plant species. However, blue and red light are more useful because green plant tissues more readily absorb them. Considering the medicinal importance of E. amoenum, the present study was conducted to improve the germination and growth characteristics under LED treatments.3. Materials and methods: This study was conducted at the University of Mohaghegh Ardabili in 2024. E. amoenum seeds were purchased from Pakan Bazr Company. After surface disinfection, the seeds were placed in Petri dishes containing wet filter paper and transferred to light chambers. Germination indices (germination percentage, speed of germination, mean daily germination, germination energy, seed efficiency, seedling efficiency, seedling vigor index, coefficient of velocity of germination, daily germination speed) were recorded for up to 21 days. Morphological indices (fresh weight of seedling, dry weight of seedling, shoot length, root length, percentage of root dry weight, percentage of shoot dry weight) were measured in 7-day-old seedlings. Then seedlings were transferred to the growing medium (peat moss and perlite), and the pots were placed in the same light chambers. After 4 weeks, biochemical indices (photosynthetic pigment content, total carbohydrate content, total protein content, and total phenol content) were evaluated. The experiment was conducted based on a completely randomized design with 4 treatments and 4 replications. The 4 light treatments included 100% white LED light (W), 100% blue LED light (B), 100% red LED light (R), and a combination of blue and red LED light (50:50, BR). The data were analyzed using SPSS Inc. version 16. Means were compared using Duncan's multiple range test at a 5% probability level. Graphs were drawn using Excel software.4. Results and Discussion: The results of the present study revealed that red light (R) treatment significantly improved germination percentage, germination speed, mean daily germination, germination energy, seed efficiency, seedling efficiency, seedling vigor index, coefficient of velocity of germination, and blue light (B) application reduced the germination of E. amoenum seeds. Similarly, E. amoenum growth characteristics, including fresh weight, dry weight, seedling length, root length, percentage of root dry weight, and percentage of shoot dry weight, increased under the positive effect of red LED light (R). Also, the blue light (B) application did not indicate any positive effect on growth indices. In biochemical indices, the application of a combination of blue and red light (BR) resulted in a significant increase in the content of photosynthetic pigments, total carbohydrate content, total protein content, and total phenol content. In addition, blue LED light (B) had a negative effect on biochemical indices compared to other treatments. In general, light quality changes can affect photosynthesis and energy production efficiency. Blue and red light are known to be the most effective wavelengths for plants, and their absorption peaks correspond to the absorption peaks of photosynthetic pigments. Therefore, their application alone and in combination can effectively increase the efficiency of photosynthesis, the synthesis of photosynthetic pigments, and the biosynthesis of macromolecules including carbohydrates and proteins. In addition, applying blue and red light increases phenolic compounds by increasing the production of enzymes related to plant secondary metabolism.5. Conclusion: The observations of the present study showed that the seeds of E. amoenum are considered in the group of plant species that require light or are photoblastic positive. Hence, the application of red LED (R) can be considered an effective treatment to improve and increase the germination and growth characteristics of E. amoenum plant at the seedling stage. In the later stages of plant growth, the response of E. amoenum to light qualities was different. The combination of blue and red light (BR) was considered an effective treatment to increase the content of photosynthetic pigments, total carbohydrates, total proteins, and total phenols.6. Acknowledgement: We would like to thank the University of Mohaghegh Ardabili for financial support.7. Keywords: Chlorophyll, Germination percentage, Morphological, Phenol, Protein
Research Article
Growing vegetables
Khosro Parvizi; Ali Ghadami firoozabadi; M. khataar; M. Ahmadian
Abstract
IntroductionThe limited amount of organic matter in most potato-growing soils in the country reduces their biological activity and limits the availability and absorption of some nutrients by plants (Khatar et al., 2017). One of the most effective management strategies in this field is to maintain and ...
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IntroductionThe limited amount of organic matter in most potato-growing soils in the country reduces their biological activity and limits the availability and absorption of some nutrients by plants (Khatar et al., 2017). One of the most effective management strategies in this field is to maintain and enhance soil organic matter, because improving the physical and chemical conditions of the soil can greatly help increase yield and achieve sustainable agriculture. Due to the limitations and high costs of livestock and poultry manure, which are used as a major part of organic fertilizers in the country, efforts should be made to benefit from new organic sources such as blood meal, which is used in smaller amounts per unit area and at the same time provides higher nitrogen content to the plant. Blood meal is also known as a growth stimulant due to its high amino acid content (Bhunia et al., 2021). So far, have been down very few experiments to investigate the effects of blood meal especially under irrigation deficit conditions. Therefore, it was necessary to investigate the effects of using blood meal as a source of nitrogen-rich organic fertilizer under stress conditions on growth traits as well as its effects on production of this important product (potato) in this project in the country. Materials and MethodsThis research was conducted as a factorial experiment based on randomized complete block design at the Hamedan Agricultural and Natural Resources Research and Education Center (Ekbatan Agricultural Research Station). In this study two potato cultivars, Bamba and Sante, were considered as the first factor. The irrigation water amount was examined at three levels (100, 75, and 50 percent of Cumulative Evapotranspiration from Class A Evaporation Pan) and fertilizer treatments at three levels (chemical fertilizer, poultry manure, and blood powder. The use of chemical fertilizer was based on soil tests. Chemical fertilizer treatment was carried out by using 120 kg of pure nitrogen with urea source (260 kg of urea fertilizer per hectare), 150 kg of triple superphosphate, 100 kg of potassium sulfate and two injections of complete micro fertilizer at the flowering stage and two weeks after that. One third of urea fertilizer was applied at the time of planting time and the two other parts were applied as a top-dress form. Complete micro fertilizer injection was also performed in two simultaneous times in the blood meal and chicken manure treatments. The drip irrigation system and the tape type were placed at a depth of five to six centimeters on the ridge and at the time of planting the tubers. The growth stage traits including time to achieve 50% germination, date of full emergence and date of full coverage, chlorophyll content, stem length, internode length, number of nodes, number and length of stolons, leaf area, fresh and dry weight of roots and stems were measured. Chlorophyll content was measured using the Gross method (Gross, 1999). At harvest time, the total yield was calculated and the tubers produced were separated into three sizes; seed, large, and small. Tuber dry matter percentage and water use efficiency were also measured. The resulting data were statistically analyzed using SAS 9.1 software, and means were compared using Duncan's multiple range test with a five percent probability level.Results and DiscussionThe results of analysis of variance in the measured traits showed that the two treatments of irrigation levels and the kind of fertilizer did not have a significant effect on the time required to achieve 50% germination and complete emergence. However, the effects of irrigation levels and fertilizer type and their interaction were significant on other growing traits including time to reach full coverage, plant height at flowering, number and length of stolons, chlorophyll content, leaf area index and fresh and dry weight of roots and stems. The tuber dry matter percentage was not statistically affected by cultivar, but irrigation treatment had a significant effect (p≤0.05) on tuber dry matter percentage. The type of fertilizer was significant (p≤0.01) on the number of tubers in all three sizes, as well as water use efficiency and on yield and percentage of tuber dry matter. The interaction effect of irrigation treatment × fertilizer type was significant on tuber production in all three sizes, as well as tuber dry matter, total yield, and water use efficiency. An increase in the ratio of nitrogen to phosphorus leads to a relative increase in stolon length. While the opposite ratio leads to a decrease in stolon length. Establishing a proportional and balanced amount of these two elements and providing sufficient amounts of them depending on the nutritional needs of the potato leads to an increase in the number of stolons (Jackson, 1999). Recent research has demonstrated that chicken manure and blood meal are capable of significantly reducing stolon length and increasing their number under stress conditions. It seems that both of these types of organic fertilizers (blood meal and chicken manure) provide the potato plant with a balanced access of nitrogen to phosphorus under stress conditions and, by relatively increasing the stolon length and helping to increase its number, delay the potato plant's tuberization stage and achieve maximum storage capacity. The results of this study showed that under severe stress conditions, the use of blood meal had also positive effect on number of tubers and total yield compared to the use of chemical fertilizer alone (control) in deficit irrigation treatments by releasing amino acids and also helping to absorb nutrients. As a result, in conditions of severe stress, the use of blood meal regulates the effects of water stress and partially compensates adverse effects of deficit irrigation. Conclusionthe results of this experiment showed that the use of chicken manure and blood meal significantly increased vegetative growth and yield of potatoes compared to chemical fertilizers. In addition, the effectiveness of both types of organic fertilizers was greater compared to chemical fertilizers under deficit irrigation conditions. Therefore the use of these two organic fertilizers, especially blood meal, can compensate the reduction of yield under water stress conditions.
Research Article
Medicinal Plants
Saeideh Mohtashami
Abstract
IntroductionPlant materials contain many bioactive compounds such as alkaloids, flavonoids, terpenoids, phenolic compounds, etc., which can be used to prepare health products, cosmetics, medicines, food additives, etc., and have great importance for improving human health and quality of life (Ahmadian ...
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IntroductionPlant materials contain many bioactive compounds such as alkaloids, flavonoids, terpenoids, phenolic compounds, etc., which can be used to prepare health products, cosmetics, medicines, food additives, etc., and have great importance for improving human health and quality of life (Ahmadian et al., 2023). In recent years, the extraction of bioactive compounds from plant materials has attracted much attention. Extracting these active compounds is a challenging task because they are usually present in small amounts in plants and special techniques and methods are required for their successful isolation (Qin et al., 2022). Bioactive substances are usually found inside or between plant cells. The main resistance factor to the diffusion of bioactive substances into the solvent during extraction is the plant cell wall (Zhao et al., 2014). In order to improve extraction efficiency, pretreatments are usually performed before the extraction operation to destroy cell wall structure, increase cell wall permeability, and promote release of active substances (Ijod et al., 2022). Cold plasma has shown a wide application prospect in food processing, pharmaceutical and health care, environmental protection, biomedicine, and many other fields due to its many advantages such as low temperature, high efficiency, low energy consumption, and environmental compatibility (Melotti et al., 2021). When cold plasma is applied to plant materials, it can destroy the cell wall structure and increase the surface hydrophilicity of the materials, thereby improving the extraction efficiency (Keshavarzi et al., 2020). Therefore, it can be widely used as a pre-extraction treatment. Nevertheless, there is no comprehensive study on DBD cold plasma pretreatment technology to enhance the extraction of bioactive compounds from plant materials, which is suitable for researchers to continue their research. Therefore, the present study aimed to investigate the effect of cold plasma pretreatment on the extraction rate of active compounds from Origanum vulgare.Materials and MethodsOregano seeds were sown in the medicinal plant farm of Jahrom University in October 2023, and aerial parts of the plant was harvested in May 2024 at the flowering stage and dried in shade. After drying, the samples were subjected to DBD cold plasma pretreatment, with air as the carrier gas and different voltages and times. Then, essential oil extraction and extraction were performed on the pretreated samples, and some of the active substances such as essential oil content, total phenolic compounds, flavones and flavonols, total flavonoids, tannin contents, antioxidant activity, and total carbohydrates were measured. In this study, a factorial experiment was conducted in a completely randomized design with 3 replications. The first factor included time at three levels (0, 3, and 6 minutes) and the second factor included voltage at two levels (20 and 30 kV). For the pretreatment of the samples for essential oil extraction, 30 g of dried marjoram plant were hand-cut and crushed for each treatment, and then 30 ml of water was added to them, and then they were placed in a plasma device. After the treatments, the samples were extracted. Plasma pretreatment was applied to investigate its effect on the phytochemical compounds in the extract, as follows: the plant samples were powdered using an electric grinder, and then five g of the powdered sample was weighed for each treatment and 25 ml of 70% methanol solvent was added to them. After the powdered samples were completely mixed with the solvent, they were placed in a plasma device for plasma pretreatment. After the treatments, the samples were extracted.Results and DiscussionThe findings of this study showed that a voltage of 30 kV for 3 minutes was more effective in extracting the non-volatile active substances of oregano and led to an increase in all of their measured traits compared to the control treatment. Also, the lowest amount of active substances measured in this study was observed in the 30 kV treatment for 6 minutes. According to the results obtained from this study, it can be concluded that the duration of plasma pretreatment has a greater effect than the output voltage on the extraction of non-volatile active ingredients. So that in this study, using a voltage of 30 kV for 3 minutes led to an increase in the active substances of oregano, while using the same voltage for 6 minutes led to the opposite result. Although the effect of plasma pretreatment on the extraction of essential oil was not significant. However, the highest amount of essential oil was measured in the control treatment and the lowest amount was in the 30 kV voltage treatment for 3 minutes, indicating the destruction of essential oil glands and loss of essential oil at this voltage. At present, the mechanism of cold plasma treatment to improve the extraction efficiency of active substances is not fully understood, but it is generally believed that it can be attributed to two possible mechanisms: the decomposition of cell wall structure and increase of surface hydrophilicity. Disruption of plant cell wall structure can reduce diffusion resistance of active substances, thereby promoting their release. Meanwhile, increase of surface hydrophilicity of materials facilitates the dissolution and diffusion of hydrophilic active substances, thereby improving the extraction efficiency (Bao et al., 2020a; 2020b).ConclusionThe findings of this study showed that a voltage of 30 kV for 3 minutes was more effective than other treatments in extracting non-volatile active ingredients of oregano and led to an increase in all measured traits compared to the control treatment. While the effect of plasma treatments on the extraction rate of essential oil was not significant.
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