مجله تحقیقات گیاهان دارویی و معطر ایران
سال چهل و یکم شماره 2 (پیاپی 124، تابستان 1404)

Salinity stress is one of the most significant abiotic stresses that impede agricultural production. It is often accompanied by oxidative stress due to the generation of reactive oxygen species (ROS). Mitigating the effects of environmental stress on plants through the use of growth-promoting compounds is of particular importance. In this context, silicon sources, such as potassium silicate, play a critical role in modulating salinity stress in plants. By enhancing plant resistance to salt stress, potassium silicate can contribute to improved growth and performance in areas with saline soils. These compounds promote cellular ion balance under adverse conditions and improve water uptake and retention in plants, thereby reducing ion leakage and the detrimental effects of salinity stress.

The present study aimed to investigate the effect of potassium silicate on the growth and physiological and biochemical characteristics of goldenrod in a factorial design based on a completely randomized design with the factor of salinity stress at three levels (0, 60, and 120 mM) and foliar application of potassium silicate at three levels (0, 50, and 100 mg/l) under greenhouse conditions. Foliar application was carried out three times at 15-day intervals. The first foliar application was performed at the 4-leaf stage. After the second foliar application, salinity stress was induced by applying 200 milliliters of sodium chloride solution to each pot for 40 days. To prevent salt accumulation in the pots, all pots were rinsed with non-saline water after every 4 irrigations with saline water. The morphological variables investigated include wet and dry weight of shoots and roots and plant height and other traits including plant pigments (chlorophyll a, b and total), relative leaf water content, ion leakage rate, proline, sodium and potassium absorption rate of roots and it was the aerial parts that were measured in the middle of the golden grass flowering period.

Salinity stress caused yield reduction, and potassium silicate moderated the negative effects of salinity stress and improved plant growth conditions. The evaluations showed that the salinity of 120 mM caused a decrease in the fresh weight of shoot (28%), dry weight of shoot (29%), fresh weight of root (38%), dry weight of root (37%), total chlorophyll (40%), the relative content of leaf water (17%), root potassium (14%) and leaf potassium (16%) and increased ion leakage (23%), proline (13%), root sodium (256%), sodium leaves (325%). Potassium silicate, especially 100 mg/l, moderated salinity stress by increasing plant weight, chlorophyll, leaf water, and potassium content in leaves and roots and reducing sodium accumulation in leaves and roots and ion leakage.

The general results of the research showed that increasing the intensity of salinity stress had negative effects on the growth and functional characteristics of golden grass and potassium silicate in the volume of 50 to 100 mM caused the adjustment of salinity stress by increasing the quantitative and qualitative performance (biochemical and phytochemical) of golden grass. Therefore, to cultivate the golden grass plant, it should be noted that the water or soil used does not contain salts such as sodium and chlorine, or soil conditioners or growth stimulants should be used for the production and cultivation of this plant.

Satureja khuzistanica Jamzad is a medicinal plant belonging to the Lamiaceae family and is one of Iran’s exclusive species. Due to its high essential oil content and significant amounts of carvacrol, it is particularly important in the cosmetic, health, and pharmaceutical industries. This study aimed to evaluate the plant’s adaptation to the climatic conditions of Isfahan province and enhance its quantitative and qualitative performance by identifying the most suitable fertilization method.

This project was conducted at Fozveh Station of the Agricultural and Natural Resources Research Center of Isfahan from 2017 to 2020 under irrigation conditions, using a randomized complete block design (RCBD) with eight fertilizer treatments. The treatments included different levels of chemical fertilizers (N50P25K25), organic fertilizers (30 and 60 tons/ha of cow manure, and 5 tons/ha of vermicompost), and combinations of chemical and organic fertilizers (N50P25K25 + 30 tons/ha cow manure, N50P25K25 + 60 tons/ha cow manure, and N50P25K25 + 5 tons/ha vermicompost). These treatments were compared with a control group, and the experiment was replicated three times. Seeds and seedlings were sourced from the Isfahan Agricultural and Natural Resources Research Center and the Research Institute of Forests and Rangelands. Cultivation was performed indirectly through seedlings, which were first grown in greenhouse conditions using cultivation trays. In April 2017, after favorable weather conditions were established, the seedlings were transplanted to the field. Drip irrigation was applied immediately after transplanting, with watering scheduled twice a week in the early growth stages and once a week after plant establishment. The aerial parts of the plants were harvested at 50% flowering, cut 5 cm above the soil surface, and dried in the shade. Essential oil extraction was performed annually using water distillation (Clevenger apparatus). The essential oil percentage was measured, its composition was analyzed using gas chromatography (GC), and qualitative assessment was conducted through gas chromatography-mass spectrometry (GC-MS).

According to the results, the maximum essential oil percentage and oil yield in S. khuzistanica were 3.7% (in the third year) and 132.6 kg/ha (in the second year), respectively. Across the experimental years, the highest oil yield was obtained in the combined treatment of 50 kg/ha nitrogen, 25 kg/ha phosphorus, and 25 kg/ha potassium, plus 5 tons/ha vermicompost, in the third year. Throughout the study, 14 compounds were identified in S. khuzistanica essential oil, with carvacrol being the predominant component. The concentration of carvacrol ranged from 86.4% to 95.3%.

According to the results, the qualitative yield of essential oil in S. khuzistanica was less affected by soil fertility treatments, while the quantitative yield showed a significant increase, which indirectly enhanced the qualitative yield. Ultimately, the study concluded that the intermediate fertilization method was the most effective treatment for improving quantitative yield and promoting sustainable agriculture. The high carvacrol content in this species adds to its economic value. Given its diverse biological properties, including antiseptic, anti-inflammatory, analgesic, antibacterial, antifungal, and antioxidant activities, S. khuzistanica is recommended for applications where this valuable compound is required.

Garlic (Allium sativum L.) exhibits strong antimicrobial activity, primarily due to its organic sulfur compounds such as thiosulfates, especially allicin. Given the environmental concerns and potential health risks associated with synthetic additives, there is growing interest in developing active, biodegradable packaging materials incorporating herbal essential oils and plant extracts. This study aimed to fabricate and assess the mechanical, physical, and antimicrobial properties of an active composite film made from polyvinyl alcohol, chitosan, and nanoclay, incorporating 2% and 4% garlic extract, for potential application in food packaging. First, separate solutions were prepared by dissolving polyvinyl alcohol (5%), chitosan (2%), and nanoclay (4%) in appropriate solvents, along with an aqueous extract of garlic. Film fabrication was carried out using the casting method, based on five experimental treatments: (1) polyvinyl alcohol (PVA) alone, (2) PVA/chitosan, (3) PVA/chitosan/nanoclay, and (4–5) PVA/chitosan/nanoclay films containing 2% and 4% garlic extract (montmorillonite-based). The mechanical properties of the films, including tensile strength (TS), elongation at break (EB), and Young’s modulus (YM), were measured using a texture analyzer. Physical properties such as film thickness were assessed with a digital micrometer, while solubility (WS), water absorption capacity (WAC), and water vapor permeability (WVP) were evaluated using ASTM standard methods. Opacity was measured via spectrophotometry. Antimicrobial activity against Staphylococcus aureus and Escherichia coli was assessed using the disc diffusion method on Mueller-Hinton agar. The diameter of the inhibition zones was recorded as an indicator of antimicrobial efficacy. Data were analyzed in a completely randomized design (CRD) with five treatments and three replications using one-way ANOVA in SPSS software, and treatment means were compared using Duncan’s test at a significance level of p < 0.05. The structural components of the films and the garlic extract concentration significantly influenced the mechanical, physical, and antimicrobial properties. The active triple composite films containing garlic extract exhibited higher tensile strength and Young’s modulus (approximately 30 MPa and 0.14 MPa, respectively) while demonstrating the lowest elongation at break. The incorporation of chitosan and nanoclay into the polyvinyl alcohol matrix increased film thickness, with triple composite films showing greater thickness (0.17 mm) and opacity. These films also exhibited the lowest values of water absorption, solubility, and water vapor permeability. Unlike most mechanical and physical properties, the antimicrobial effectiveness of the films was directly dependent on garlic extract concentration. In general, the garlic extract showed stronger antibacterial effects against gram-positive S. aureus than gram-negative E. coli. In films containing 2% and 4% garlic extract, the inhibition zones for S. aureus measured 21.6 mm and 26.55 mm, respectively, and for E. coli, 16.5 mm and 19.1 mm, respectively. The active triple composite film (polyvinyl alcohol/chitosan/montmorillonite) containing 4% garlic extract demonstrated the lowest WVP and higher values for TS, YM, and thickness. These characteristics enable the film to minimize moisture transfer, preserve the structural integrity of packaged food, and delay spoilage, thereby extending shelf life. Hence, enriching biodegradable triple composite films with garlic extract presents a promising approach for developing innovative food packaging materials with extended storage capabilities.

The use of chemical fertilizers to produce high-yield crops in the shortest possible time has raised public concerns regarding food sustainability, safety, and security. Consequently, alternatives such as biofertilizers are necessary to ensure food safety and sustainability. Biofertilizers are essential tools in sustainable agriculture and can enhance plant resilience to environmental stresses. Their application in the cultivation of medicinal plants, whose primary purpose is to promote public health, is steadily increasing. The medicinal plant Dracocephalum moldavica L., commonly known as dragonhead and a member of the mint family, contains essential oils throughout its tissues. In traditional medicine, it is used to treat mental fatigue, migraines, cardiovascular ailments, congestion, headaches, stomach pain, liver disorders, and as a sedative. This study aims to investigate the effects of biofertilizers on the growth and essential oil properties of dragonheads under the climatic conditions of Khuzestan. The influence of biofertilizers on the growth, yield, and both the quantity and quality of essential oil in dragonhead was assessed using a randomized complete block design with seven treatments and three replications. The study was conducted at the Department of Horticultural Science, Khuzestan Agricultural Sciences and Natural Resources University, in 2022. Following soil analysis and land preparation, seedlings were transplanted to the main field in March. All agronomic practices, including irrigation and weed control, were uniformly applied across treatments. The treatments consisted of a control (no fertilizer - C), inoculation with bio-potassium (K), bio-nitrogen (N), bio-phosphate (P), a combination of bio-nitrogen and bio-phosphate (NP), bio-nitrogen and bio-potassium (NK), and a combination of all three (NPK). The aerial parts of the dragonhead were harvested at the flowering stage. Evaluated traits included plant height, number of inflorescences, length of the main inflorescence, fresh weight, dry weight, essential oil content, dry weight yield, and essential oil yield. Essential oils were extracted through water distillation using a Clevenger apparatus, and their components were identified via gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Data were analyzed using SAS statistical software (version 9.1), and means were compared using Duncan’s multiple range test at a 5% significance level. Charts were created using EXCEL software. Analysis of variance indicated that biofertilizers significantly influenced all measured traits in dragonhead. Mean comparison results showed that the highest plant height (90.08 cm) was achieved with the P treatment. The NPK treatment produced the highest number of inflorescences (11.91), length of the main inflorescence (31.10 cm), fresh weight (50.31 g), dry weight (11.31 g), essential oil percentage (2%), dry weight yield (3393.5 kg/ha), and essential oil yield (69.19 kg/ha). The lowest values for plant height (71.50 cm), number of inflorescences (4.12), inflorescence length (17.75 cm), aerial fresh weight (15.68 g), dry weight (3.98 g), dry weight yield (1194.75 kg/ha), and essential oil yield (4.98 kg/ha) were observed in the K treatment, while the N treatment had the lowest essential oil percentage (0.44%). GC-MS analysis revealed that essential oil composition varied among treatments. The highest neral content (17.5%) was found in the P treatment; geraniol (7.9%) and neryl acetate (2.5%) were highest in the NPK treatment; geranial (32.1%) was most abundant in the K treatment; and geranyl acetate (73.2%) was highest in the NK treatment. The findings suggest that the combined application of biofertilizers, particularly the NPK combination, optimizes both yield and essential oil production in dragonhead under similar environmental conditions. It is anticipated that, under such conditions, and without reliance on chemical fertilizers, cultivating this medicinal plant within a sustainable agricultural framework can yield healthy, high-quality, and environmentally friendly essential oils.

Considering the limitations on the use of growth-promoting antibiotics due to the emergence of antibiotic resistance, the use of plant-based growth promoters in the livestock and poultry industries has garnered significant attention in recent decades. These alternatives are recognized for their beneficial effects on animal growth, immune function, and physiological status. It appears that with new technologies such as nanoencapsulation, the application of plant essential oils in commercial products can become more cost-effective while enhancing performance and reducing feed costs. Therefore, this experiment investigated the effects of three commercial plant growth promoters on performance, feeding cost per kilogram of live body weight, carcass characteristics, and immune responses in broiler chickens.  randomized design comprising five treatments with four replicates of 30 birds each. The experimental treatments were as follows: 1) a control diet (no additive), 2) a diet containing Virginiamycin (100 g per ton of feed) as a positive control, and 3 to 5) diets containing Novi-Herb®, Novi-Grow®, and Novi-Herb+® (each at 100 grams per ton of feed). Novi-Herb® included essential oils from thyme (Thymus vulgaris), ajwain (Trachyspermum ammi), and oregano (Origanum vulgare), along with a nanocapsulated form of chitosan. Novi-Grow® contained organic acids (lactic and formic acid), prebiotics (lactose and yeast cell wall), and plant-based compounds such as garlic powder (Allium sativum), turmeric powder (Curcuma longa), and cinnamon powder (Cinnamomum verum). Novi-Herb+® combines essential oils of lemon (Citrus limon) and yeast cell wall with other ingredients found in Novi-Herb®. Recommendations from the local veterinarian implemented the vaccination program. Data was collected on feed intake, body weight, livability, feed conversion ratio, production index, and feeding cost per kilogram of live body weight from day 1 to 42. On day 42, blood samples were taken from three birds per replicate to perform differential white blood cell counts and evaluate antibody titers against Newcastle and Influenza vaccines. Additionally, four birds per replicate, selected based on average body weight, were slaughtered. After weighing and stuffing, carcass yield and the relative weights of body components (breast, thigh, neck, back) and internal organs (liver, heart, gizzard, spleen, bursa of Fabricius, gall bladder, and proventriculus), as well as abdominal fat, were measured.  Including the evaluated plant growth promoters in the diet significantly improved body weight and feed conversion ratio at 42 days of age compared to the control group (P < 0.05). There were no significant effects of the treatments on livability, the European production index, or feed cost per kilogram of live body weight (P > 0.05). However, the use of Novi-Herb®, Novi-Grow®, and Novi-Herb+® led to cost reductions of 4.8%, 4.1%, and 2.7%, respectively, compared to the control group, and 3.5%, 2.8%, and 1.4%, respectively, compared to the Virginiamycin group. Among the measured traits, only the relative weight of abdominal fat showed a significant decrease with the inclusion of the plant-based growth promoters (P < 0.05). Dietary treatments did not significantly affect the percentage of heterophils, lymphocytes, the heterophil-to-lymphocyte ratio, or antibody titers in response to Newcastle and Influenza vaccine injections (P > 0.05). Based on the results, the evaluated plant growth promoters can serve as effective alternatives to antibiotic growth promoters by improving broiler performance and numerically reducing feed cost per kilogram of live body weight.

Garden thyme (Thymus vulgaris L.) is prominent among medicinal plants due to its applications across various industries. Salinity is the second most significant environmental factor limiting agricultural productivity in many regions worldwide, including Iran. Biofertilizers, which supply macro- and micronutrients, amino acids, and plant hormones, can enhance plant growth and improve stress resistance. This study examined the effects of thyme extract (Thymbra spicata), seaweed, and a comprehensive bacterial biofertilizer on garden thyme's morphophysiological traits, biochemical characteristics, essential oil yield, and secondary metabolite production under salt stress conditions. This research was designed and implemented as a factorial experiment based on a randomized complete block design with three replications, conducted in the medicinal plant research greenhouse of Ilam University. The first factor included treatments of 10% T. spicata extract (TS), 1% seaweed (SB), 10% complete bacterial biofertilizer (BB), and their combination (TS+SB+BB). The second factor involved three salinity levels: 0, 100, and 200 mM sodium chloride (S0, S100, and S200). In this study, in addition to morphological traits, the following parameters were measured: relative water content, electrolyte leakage, total chlorophyll, carotenoid and anthocyanin contents of shoots, total phenol, flavonoid, total protein, soluble sugar, proline, malondialdehyde, the enzyme activities of catalase and phenylalanine ammonia-lyase, antioxidant activity, and essential oil content. Essential oil components were also identified using GC and GC/MS. After data collection, the results were analyzed statistically using SAS 9.3 software, and Duncan’s multiple range test was used to compare means at a 5% probability level. The findings were presented in tables and graphs using Excel. Based on the results, increasing salinity stress led to a decline in the average values of morphological, physiological, and biochemical indices of T. vulgaris. However, the application of biofertilizer treatments mitigated the adverse effects of salinity. According to the mean comparisons, under both non-stress and salinity stress conditions, the highest morphological indices were observed in the combined treatment of TS+SB+BB. This combined treatment also enhanced relative water content, chlorophyll, carotenoid, anthocyanin, total phenol, flavonoid, total protein, soluble sugar, and proline at all stress levels. In terms of carotenoid, anthocyanin, total phenol, flavonoid, proline, soluble sugar, catalase, and phenylalanine ammonia-lyase enzyme activities, and antioxidant properties, values generally increased with higher stress levels. The highest phenylalanine ammonia-lyase activity and antioxidant activity were recorded under both non-stress and moderate stress conditions with the TS treatment, while under high-stress conditions, the TS+SB+BB combination showed the greatest activity. Salinity stress also increased electrolyte leakage and malondialdehyde (MDA) content. However, at all three salinity levels, the application of the TS+SB+BB treatment significantly reduced electrolyte leakage and MDA content. In this study, the highest essential oil content was observed under moderate salinity stress (S100) in plants treated with the TS+SB+BB combination, which also increased thymol content by 45% compared to the control. The results of the morphophysiological and biochemical assessments, along with essential oil analysis of garden thyme, revealed a significant decline in photosynthetic activity under salt stress conditions. This reduction was accompanied by decreased leaf water status and a decline in various growth and biochemical parameters. The interaction between salinity stress and the TS+SB+BB biofertilizer treatment demonstrated that plants receiving the combined treatment experienced less reduction in growth, physiological, biochemical, and essential oil parameters under high salinity stress compared to untreated controls. Overall, it can be concluded that the combined biofertilizer treatment effectively mitigates the negative effects of salinity stress, supporting improved quantitative and qualitative performance of garden thyme under adverse conditions.

Antioxidants are a group of chemical compounds naturally present in many foods. These compounds help protect the body’s cells and tissues from oxidative damage by neutralizing free radicals. The most important natural antioxidants are found in grains, vegetables, fruits, and spices. Frankincense (Boswellia thurifera) is a medicinal plant traditionally used in Arabic medicine to enhance memory. Mastic gum, derived from the shrub Pistacia lentiscus, possesses numerous medicinal properties and is considered a medicinal plant. The chemical compounds extracted from frankincense and mastic gums using various solvents may exhibit different antioxidant properties. Consequently, this research aimed to investigate the reducing power, as well as the phenolic and flavonoid contents, of frankincense and mastic extracts prepared using different solvents.

Acetone, ethyl acetate, hexane, ethanol, methanol, and ether were selected as solvents for extracting frankincense and mastic gums using a rotary evaporator. The resulting extracts were analyzed to evaluate their reducing power, antioxidant activity, and free radical scavenging ability using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Additionally, the total phenolic content was determined using the Folin–Ciocalteu method, and the total flavonoid content was measured using the aluminum chloride colorimetric method.

In the experiments performed with extracts obtained using various solvents (acetone, hexane, ethyl acetate, methanol, ether, and ethanol), the lowest EC50 value was observed in the hexane extract of frankincense (2.24 mg/mL), and the acetone extract of mastic (3.10 mg/mL), indicating the highest reducing power. Conversely, the highest EC50 values—indicative of the lowest reducing power—were found in the hexane extracts of frankincense (64.75 mg/mL) and mastic (12.59 mg/mL). Regarding total phenolic content, the ethanolic extract of frankincense had the highest value (0.2675 mg/mL), while the hexane extract had the lowest (0.0825 mg/mL). For mastic extracts, the acetone extract exhibited the highest phenolic content (0.261 mg/mL), and the methanolic extract showed the lowest (0.086 mg/mL). As for total flavonoid content, the highest amounts were recorded in the ether extracts of mastic (0.133 mg/mL) and frankincense (0.161 mg/mL). The lowest flavonoid content was found in the methanolic extract of mastic (0.0185 mg/mL) and the ethanolic extract of frankincense (0.0435 mg/mL).

The findings of this study indicate that extracts of mastic and frankincense obtained using acetone, ethanol, methanol, ethyl acetate, hexane, and ether exhibited significant antioxidant activity. Among the frankincense extracts, the methanolic extract, with the highest EC50 value, demonstrated the lowest antioxidant activity, while the hexane extract, with the lowest EC50, had the highest antioxidant activity. Similarly, for mastic, the hexane extract showed the lowest antioxidant activity (highest EC50), while the acetone extract exhibited the highest antioxidant activity (lowest EC50). Another objective of the study was to assess the phenolic and flavonoid content of mastic and frankincense extracts in different solvents. The highest phenolic content was found in the ethanolic extract of frankincense and the acetone extract of mastic, while the lowest was observed in the hexane extract of frankincense and the methanolic extract of mastic. For flavonoids, the ether extracts of both mastic and frankincense gums contained the highest levels, whereas the methanolic extract of mastic and the ethanolic extract of frankincense contained the lowest. Given the strong correlation between phenolic and flavonoid content and antioxidant activity in frankincense and mastic, these plants can serve as valuable natural sources of antioxidants for human health and have potential applications as effective medicinal agents.

Mentha longifolia L. belongs to the Mentha genus and the mint family (Lamiaceae). This plant naturally grows in moist environments, such as riverbanks, and its cultivation in fields and greenhouses requires high-quality water. Water and soil salinity are among the most critical agricultural challenges in hot and arid regions. In such areas, soil salinity and water scarcity are the primary factors that reduce the growth and yield of crops. Identifying and utilizing ecotypes and cultivars resistant to salinity stress can help prevent production losses. This study aims to investigate the effects of different water salinity levels on the morphological and physiological traits of three wild brookmint ecotypes to identify the most salt-tolerant ecotype. This study was conducted using a completely randomized design in factorial form with two factors at Ferdowsi University of Mashhad. The first factor was ecotype, with three levels (E1: South Khorasan, E2: Lorestan, E3: Fars), and the second factor was salinity stress, with four levels (0, 75, 100, and 150 mM sodium chloride). Salt stress treatments were applied beginning at the four-leaf stage, and at the eight-leaf stage, morphological traits were measured, including plant height, number of leaves, number of flowers, flower length, fresh and dry leaf weights, and fresh and dry root weights. Physiological traits assessed included chlorophyll a, chlorophyll b, total carotenoids, electrolyte leakage, total phenol content, total flavonoid content, proline content, and total carbohydrate content. Data was analyzed using Minitab 19 software. The results showed that the main effects of ecotype and salinity stress and their interaction significantly influenced morphological traits such as plant height, root weight, and root dry weight. The main effects of ecotype and salinity stress on leaf weight and leaf dry weight were also significant. However, the main and interaction effects on traits such as number of leaves, number of flowers, and flower length were not significant. Salinity stress significantly reduced morphological traits in all ecotypes compared to the control, including plant height, leaf weight, dry weight, root weight, and dry weight. Regarding physiological traits, the main effects of ecotype and salinity stress, along with their interaction, significantly affected chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, electrolyte leakage, total flavonoid content, and proline content. The main effects of ecotype and salinity stress on total phenol content were significant, while their effects and interactions on carbohydrate content were not significant. Salinity stress led to a reduction in chlorophyll a, b, total chlorophyll, and carotenoids. Conversely, this stress increased proline content, electrolyte leakage, and the levels of total phenol and flavonoid compounds in the leaves compared to the control. Based on the evaluation of the measured traits in the three wild brookmint ecotypes, it was evident that these ecotypes responded differently to salinity stress. The results indicated that the E1 ecotype (South Khorasan) was superior to the others in terms of the traits studied and exhibited greater tolerance to salinity stress conditions.

Drought stress is one of the most critical factors influencing agricultural production, particularly in irrigated farming systems in arid and semi-arid regions of the world. Organic fertilizers can mitigate the detrimental effects of drought stress on medicinal plants. Developing new management strategies is essential to alleviate the negative impacts of drought. Among the most effective approaches to plant nutrition management under drought conditions is the use of organic fertilizers, which significantly contribute to sustainable agriculture advancement and expansion. Therefore, this study aimed to investigate the effects of different organic fertilizers in the cultivation medium of black seed and their influence on physiological traits and seed yield under various irrigation intervals.

This experiment was conducted using a completely randomized block design with two factors and three replications. The first factor included four irrigation regimes: 20%, 40%, 60%, and 80% depletion of field capacity moisture. The second factor involved planting beds composed of different organic materials at 5% (w/w) of pot soil, including normal soil (control), normal soil + biochar, normal soil + compost, normal soil + vermicompost, and normal soil + animal manure. Each pot contained six kilograms of soil. Initially, the soil was passed through a 2 mm sieve, and organic fertilizers were manually mixed with the soil in each pot at a rate of 5% by weight. On February 19, black seeds were sown in plastic pots, with fifteen seeds per pot. Two weeks after sowing, at the three-leaf stage, seedlings were thinned to six plants per pot. After planting, all pots were irrigated uniformly. Upon the emergence of black seed plants and at the four- to five-leaf stage, irrigation treatments were applied based on the designated moisture depletion levels (20%, 40%, 60%, and 80%). Measured plant responses included leaf nitrogen, phosphorus, and potassium content; ion leakage; relative water content; malondialdehyde concentration; chlorophyll a and b content; and catalase and peroxidase enzyme activities. Finally, variance analysis was conducted, and means were compared using Duncan’s multiple range test.

The findings indicated that increased drought stress led to reduced nitrogen, phosphorus, and potassium content in the leaves. Conversely, the highest concentrations of these nutrients were observed under treatments with normal soil + vermicompost or animal manure. Rising drought stress also reduced leaf relative water content; specifically, irrigation at 40%, 60%, and 80% moisture depletion led to significant reductions of 7%, 15%, and 32%, respectively, compared to 20% moisture depletion. At 60% depletion, compost, vermicompost, and animal manure treatments significantly reduced ion leakage by 11.8%, 14.5%, and 12.2%, respectively. Under 80% depletion, compost, and vermicompost significantly decreased malondialdehyde levels by 15.2% and 17.8%, respectively, relative to the control. At 20% and 60% depletion, the highest total chlorophyll content was observed in normal soil combined with vermicompost, followed by animal manure and compost. Catalase and peroxidase activities increased progressively with drought severity. At 80% depletion, the dry weight of aerial parts increased by 46% and 56% in the animal manure and vermicompost treatments, respectively, compared to the control. Likewise, grain weight increased by 26% and 32% under these treatments at the same drought level.

The results demonstrated that drought stress adversely affected black seed plants' nutrient concentration and physiological traits. Applying normal soil with vermicompost or animal manure effectively enhanced photosynthetic pigment levels, promoting plant growth. Compared to vermicompost and animal manure, biochar, and compost had a relatively lower impact on improving grain yield. Overall, vermicompost and animal manure are recommended for cultivating black seed under varying humidity conditions.

Malus domestica Borkh. ‘Red delicious’ is one of the most economically significant fruit crops cultivated worldwide, including in Iran, with its aroma arising from a complex mixture of volatile compounds that define its sensory profile and vary across species and cultivars. Deep eutectic solvents (DESs) represent an innovative class of solvents distinguished by their non-flammability, negligible volatility, low vapor pressure, thermal stability, biodegradability, minimal toxicity, and reusability, excelling in extracting bioactive compounds while preserving their structural and functional integrity while also serving dual roles as reaction media and catalysts in organic synthesis to enhance bioavailability. Headspace single-drop microextraction (HS-SDME) is a highly efficient technique for analyzing volatile and semi-volatile compounds, eliminating matrix interference with minimal solvent use, making it ideal for essential oil extraction.

This study developed an HS-SDME method for extracting apple essential oils using newly designed DESs, followed by GC/MS analysis, with key parameters, including DES composition, drop volume, sample weight, extraction temperature, and time, systematically optimized, evaluating three DESs composed of choline chloride paired with ethylene glycol, phenol, or 4-chlorophenol as hydrogen bond donors, and comparing the results with conventional hydrodistillation (HD) using a Clevenger apparatus.

Among the tested solvents, the combination of choline chloride and 4-chlorophenol demonstrated the highest extraction efficiency for the target analytes. Several experimental parameters influencing the efficiency of essential oil extraction using the DESs-HS-SDME method were optimized as follows: a eutectic solvent volume of 3 mL, an extraction time of 50 minutes, an extraction temperature of 80 °C, and a sample weight of 3 g. Using the DESs-HS-SDME method, 22 compounds were isolated from apple essential oil, consistent with the results obtained from the HD method. Of these compounds, 76% were monoterpenes, including α-thujene, α-pinene, camphene, sabinene, β-pinene, myrcene, α-phellandrene, p-cymene, β-phellandrene, Z-β-ocimene, E-β-ocimene, γ-terpinene, terpinolene, α-pinene oxide, trans-sabinene hydrate, cis-verbenol, neo-3-thujanol, carvacrol ethyl ether, and terpinen-4-ol acetate. Additionally, 20% were sesquiterpenes, comprising bicyclogermacrene, (E,E)-α-farnesene, germacrene B, spathulenol, and epi-cedrol. Notably, α-phellandrene, α-pinene, β-pinene, sabinene, and p-cymene were the most predominant compounds in both analytical methods employed.

In this study, an analytical procedure was proposed for the first time for extracting essential oil from apple fruit using headspace single-drop microextraction (HS-SDME) with deep eutectic solvents (DESs). Unlike previous studies, which employed conventional solvents for HS-SDME, this work introduces DESs as a greener and more effective alternative. The DESs-HS-SDME method provides an environmentally friendly, simple, and efficient approach for essential oil extraction from apple fruit. Given their low toxicity, biodegradability, and tunable properties, DESs show great promise as suitable extraction media for isolating volatile compounds from natural samples using HS-SDME.

Urtica dioica L. is a highly valued medicinal plant traditionally used to treat various diseases. Its extracts contain bioactive compounds such as flavonoids, leucoanthocyanidins, and carotene, contributing to its well-documented anticancer, antidiabetic, and antioxidant properties. Given the crucial role of elicitors in enhancing the production of plant secondary metabolites and improving medicinal quality, this study investigates the stimulatory effects of zinc oxide nanoparticles (ZnO-NPs) on the biochemical and metabolic properties of Urtica dioica callus cultures. Nettle (Urtica dioica) seeds were cultured on half-strength Murashige and Skoog (½ MS) medium to obtain sterile seedlings. Internode explants from these seedlings were then excised and transferred to full-strength MS medium supplemented with 1 mg.l-1 benzylaminopurine (BA) and 2.5 mg.l-1 naphthaleneacetic acid (NAA) to induce callus formation. Cultures were maintained under a 16/8 h light/dark photoperiod at 24 °C. Homogeneous calli were obtained through successive subcultures. These calli were then transferred to liquid MS medium and treated with zinc oxide nanoparticles (ZnO-NPs) at 0, 25, and 50 mg.l-1  concentrations. Samples were collected at 12, 24, 48, and 96 hours post-treatment. Biochemical and metabolic parameters, including the activities of catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia lyase (PAL), as well as total protein, total phenolics, quercetin, and kaempferol contents, were measured. The experiment was arranged in a completely randomized design (CRD) using a factorial layout with two factors: ZnO-NP concentration and sampling time, each with three replications. The results showed that polyphenol oxidase (PPO) activity significantly increased 48 hours after ZnO-NP treatment, particularly at a concentration of 25 mg.l-1. Phenylalanine ammonia lyase (PAL) activity peaked at 12 hours post-treatment at the same concentration (25 mg.l-1). Peroxidase (POD) activity increased only at 12 hours following treatment with 50 mg.l-1  ZnO-NPs, while it declined under all other conditions. Catalase (CAT) activity was highest at 12 hours after ZnO-NP application at 25 mg.l-1. Total protein content increased at two distinct points: 24 hours after treatment with 25 mg.l-1 and 96 hours after treatment with 50 mg.l-1  ZnO-NPs. High-performance liquid chromatography (HPLC) analysis showed no detectable kaempferol at its expected retention time, while quercetin was detected. The highest quercetin accumulation occurred at 25 mg.l-1  ZnO-NPs after 96 hours, and at 50 mg.l-1 after 48 hours of treatment. This study demonstrated that ZnO-NP elicitation enhanced the activities of key antioxidant and metabolic enzymes, catalase, peroxidase, polyphenol oxidase, and phenylalanine ammonia lyase, as well as increased total protein, total phenolic content, and quercetin accumulation in Urtica dioica callus cultures, depending on concentration and exposure time. These findings suggest that ZnO-NPs can serve as effective elicitors to boost the medicinal and metabolic potential of nettle in vitro. To translate these results into practical applications, further research is needed to optimize large-scale culture systems, such as bioreactors, for cost-effective production.