Journal of Horticultural Science

Abstract Introduction
 Plant growth and yield are affected often by stress conditions, especially drought, which is the most important factor in reducing crop production worldwide. Silybum marianum is an important pharmaceutical crop with great potential as a multipurpose plant for low-input cropping systems of the arid and semiarid regions.
Materials and Methods
 In this experiment, the effect of drought stress (full irrigation at field capacity; no stress, irrigation at 70% of field capacity; mild stress and irrigation at 40% of field capacity; severe stress) on physiologic traits, the amount of silybin a and b and 1000 seed weight in milk thistle was studied in the research field of Shahid Beheshti University in 2017-2018. The experimental site is located in Shahid Beheshti University, Tehran, Iran (51.23°N, 35.48°E, and 1769 m above mean sea level). It has a moderate and mountainous climate with a mean annual rainfall of 145.2 mm and a mean temperature of 22ºC. This experiment was performed in a completely randomized block design with 3 replications. Milk thistle seeds were prepared from Isfahan Pakanbazr Company. The soil composition consisted of 1/3 clay, 1/3 sand, and 1/3 leaf composts. The field area was 150.0 m². Furrows were created to implement this study. The space of plants on rows was 0.5 m and between rows was 1 m. In general, 15 furrows were created and 15 plants were cultured on each furrow, so the total number of plants cultivated on the field was 225. Drought stress was applied at flowering stage. Soil moisture was measured by the weighing method. The soil samples were taken from various areas (randomly) of the field, three samples each day. After measuring the water content at F.C, based on that, the amount of 70%F.C and 40%F.C was also calculated. At the time of stress, F.C irrigation was performed every two days, 70% F.C irrigation every 4 days, and 40% F.C irrigation every 6 days. After 8 days, leaf sampling was performed to measure catalase, ascorbate peroxidase, proline and malondialdehyde content and seed sampling was performed to 1000 seed weight and extract analysis. For physiologic measurements, 3 plants were randomly assigned to each stack and their leaves were separated and transferred to the laboratory. Then, in the next step, their physiologic parameters (include Catalase and ascorbate peroxidase, proline and malondialdehyde content) were measured according to the relevant protocol. In order to measure silybin, 4 plants were randomly considered to each stack and their seeds were harvested and combined and dried in shade condition in the laboratory for one month. The dried seed samples were completely powdered using a mill, then 10 g of the powders weighed and the oil extract of them was isolated by Soxhlet using n-hexane solvent. The extraction temperature was 70 °C and the extraction time was 6 h. After the extraction was completed, the extract was poured into dark glass. Next, the oil-free powder was dried in an incubator at 37 ° C. Methanol extract of oil-free powder was extracted using methanol solvent. For this purpose, 2 g of samples powder was weighed and 200 ml of 80% methanol was added to each of them and the mixture stirred for two days by Shaker. The mixture was then passed from a filter paper and after that, 200 ml of 80% methanol was added to the sample precipitate (on filter paper) and placed again on the shaker. After 24 h, extraction was performed by the same method and were added to the previous extract. The extracts were then concentrated in the environment temperature for two weeks. Concentrated extracts (powder) as well as standard silymarin with certain concentrations were dissolved in methanol solvent and used for injection into HPLC (Model: Infinity1260, Manufacturer: Agilent) using syringe filters with a diameter of 0.2 μm. After receiving the HPLC results, the data and peaks were analyzed and the amounts of silybin a and b were determined and compared at different levels of water stress. Statistical analysis of data was performed using R 3.6.1 and RStudio 1.1.463 software. Mean data were compared using Duncan's test with agricolae package at a significance level of 0.05.
Results and Discussion
 The results showed that with increasing water stress intensity, the amount of silybin a and silybin b increased by 24% and 26%, respectively. The amount of these compounds in 40% were significantly higher than other treatments, so that its amount compared to F.C treatment (26.07 mg/g Grain DW in silybin a and 40.74 mg/g Grain DW in silybin b) and compared to the 70%F.C (25.32 mg/g Grain DW in silybin a and 34.64 mg/g Grain DW in silybin b) was higher. This indicates carbon assimilation from photosynthesis to produce secondary metabolites in this treatment. Also, the amount of silybin b compared to silybin a in all treatments was (0.8: 1.2), in which 1.2 is related to silybin b and 0.8 is related to silybin a. In severe stress treatment (40% of field capacity), the amount of silybin a and b (67.30 and 98.92 mg/g, respectively) increased significantly compared to other treatments. According to the mean comparison results, the highest activity of catalase (5.16 U/ml) and ascorbate peroxidase (2.26 U/ml) was observed in mild stress treatment. Proline content gradually increased with increasing stress intensity and reached its peak in severe stress (3.36 µM/gr). Lipid peroxidation also had their maximum in severe stress (8.35 nmol/grFW). The 1000 seeds weight was reduced by 6.8 g in severe stress treatment (40%F.C) compared to the control (F.C). 
Conclusion
 According to the results, the amount of milk thistle flavonoids can be increased for medicinal purposes including the treatment of liver disease and hepatitis by applying dehydration stress.

Abstract Introduction
 Due to their pleasant and soothing taste and odor, attractive colors, and medicinal purposes, Chrysanthemum morifolium flowers have been widely used as food, tea, ornamentation, and medicine. It has been reported that C. morifolium can reduce hyperactivity of the liver, improve eyesight and regulate cellular immunity. Pharmacological investigations have shown that Flo's chrysanthemum exhibits antibacterial, antioxidant, anti-inflammatory, and heart-protective characteristics. Previous phytochemical studies on caffeic acid derivatives, flavonoids, triterpenoids, glycosides and alkaloids have been isolated from Flo's chrysanthemum. In this study, chrysanthemum cultivars were evaluated in terms of having secondary compounds and desirable medicinal properties, as well as antibacterial effects to introduce superior cultivars and purposeful planning for breeding research. The purpose of the present study, 25 cultivars of C. morifolium were compared in terms of essential oil content, leaves total phenolic, flavonoid and antioxidant activity.
Materials and Methods
 In this experiment, 25 chrysanthemum cultivars were studied in terms of essential oil percentage, antioxidant index, total phenol and flavonoid content and antibacterial effects in a randomized complete block design in Lorestan University research farm in the year 2016. Essential oil was extracted from dried flowers in the shade using a Clevenger apparatus for 3 hours. Evaluation of antioxidant activity of the extract was measured by DPPH method based on the method of Kulisic et al. (2004). The amount of flavonoids was measured by aluminum chloride and total phenol by Folin - Ciocalteu reagent colorimetric. Ward analysis was done to classify the cultivars.
Results and Discussion
The results of analysis of variance showed that the studied chrysanthemum cultivars had significant differences in terms of all studied phytochemical traits. According to the obtained results, among different cultivars, the total amount of phenolic compounds is between 14.52-47.90 mg/g dry weight, the total flavonoid content is between 11.59-55.62 mg/g DW and IC₅₀ index varied between 83.92 and 257.43 μg/ml. The highest amount of total phenol was present in Avadis and Dila cultivars (45.86-47.90 mg/g dry weight), while Yasamin cultivar (14.52 mg/g DW) had the lowest amount. Also, in terms of total flavonoid content, Golnar and Farahnaz cultivars had the highest total flavonoid content with 55.62 and 53.01 mg quercetin/g DW, respectively. Cluster analysis divided all studied cultivars into five groups. The percentage of essential oil among different cultivars varied between 0.41 to 0.62% and a high variability was observed in terms of the amount of essential oil in the studied cultivars. The highest percentage of essential oil was related to Farhnaz and Elmira2 cultivars. In general, the results showed high antioxidant activity of most cultivars. Therefore, chrysanthemum extract can be introduced as a suitable source of natural antioxidants. Also in this study, Paridokht, Sana and Ashraf cultivars were studied in terms of antioxidant and antibacterial index and Farahnaz and Elmira 2 cultivars appeared superior to other cultivars in terms of essential oil production. Hedaei et al. (2018) studied evaluation of some bioactive compounds and antioxidant activity of leaf methanolic extract and flower essential oil content from different cultivars of Chrysanthemum morifolium, in this review, total phenol and flavonoid contents and IC₅₀ values in different cultivars were ranged from 17.63-33.20 mg/g DW, 12.62-53.17 mg quercetin/g, and 54-228 μg/ml respectively. The highest phenolic content was in cultivar “Poya3” (33.20 mg/g DW), whereas the cultivar “Sahand2” (17.63 mg/g DW) contained the lowest value. Also, in terms of total flavonoid content, cultivars “Marmar” and “Sahand 2” had the highest and the lowest flavonoids with 53.17 and 12.62 mg quercetin per gram, respectively. 
Conclusion
 The results of the present study indicate a significant difference between different cultivars in terms of the total amount of phenolic, flavonoid and antioxidant compounds that the existence of such diversity can be the role of cultivar and genetics in the production of these compounds. According to the results of this study, chrysanthemum cultivars with desirable levels of phenolic and flavonoid compounds can be used as a source of natural antioxidants as an alternative to synthetic antioxidants. In this study, Sana, Paridokht and Ashraf cultivars appeared superior to the existing genotypes in terms of phytochemical and antibacterial traits. The results of this study can be used to select the correct parents for purposeful crosses in subsequent chrysanthemum breeding programs in order to improve the phytochemical traits of existing cultivars.

Abstract Introduction
 NaCl Salinity is one of the major environmental stressors affecting agricultural production everywhere. Salinity impacts the plants by the osmotic stress, nutritional imbalance with plants cells and by reducing the nutrients absorption and reactive oxygen species over-generation, as well as by ionic competition for the absorption, translocation, distribution and ion toxicity inside plants. Under salinity stress, plants develop various physiological and biochemical mechanisms to overcome this conditions, like ion homeostasis and compartmentalization, ion uptake, biosynthesis of osmoprotectants, activation of antioxidant enzymeic (superoxide dismutase, catalase, ascorbate peroxidase and glutathione peroxidase) and nonenzymic compounds (proline) to overcome salinity stress. Optimum nutrition under stressful saline conditions is important to overcome the problem and to produce optimum yield. Pelargonium graveolens is a plant commonly used in food and pharmaceutical industries. Iran has favorable micro-climates for the Pelargonium graveolens, production, and since this plants is in common use with diverse industries, this experiments was conducted to study the effects of foliar spray with Se and nano Fe on growth and physiological traits Pelargonium graveolens under NaCl salinity depression
Materials and Methods
 Two separate experiments were concluded to evaluate the effects of foliar application of selenium and nano-Iron (0, 1.5 and 3 mgL^-1) on pelargonium under saline (0, 50 and 100 mM) conditions as factorial based on Completely Randomized Design. In the first experiment, the effects of magnetized Iron and in the second experiment, the effect of selenium were assayed on pelargonium growth and physiological traits (plant dry weight, enzymic activity, elemental content, essential oil percent and oil constituents) under salinity stress.
Results and Discussion
 The results obtained from the first experiment showed that, the aerial parts dry weight, Na, Fe and H₂O₂ content, catalase activity and oil percent of Pelargonium graveolens were independently affected by the salinity and (1.5 and 3 mgL^-1) Fe foliar treatment. At the first experiment the highest amount of K/Na ratio, flavonoid content, K content, malondialdehyde, proline and superoxide dismutase activity were influenced by salinity stress. The top amount amount of plant dry weight, Fe content, K/Na, Na and superoxide dismutase activity were recorded at control plants. The top amounts of Na, proline, malondialdehyde, H₂O₂ content were recorded at 100 mM salinity stress. control and 50 mM NaCl increased oil percent in plants. Foliar spray with 1.5 and 3 mgL^-1 Fe increased catalase, yield, phenolic content and oil percent in plants. At the second experiment; aerial parts dry weight, proline and flavonoid content were influenced by salinity stress. Catalase activity, malondialdehyde, superoxide dismutase activity and H₂O₂ content were influenced by sole effects of salinity and Se foliar application. Under non saline condition, plant dry weight, superoxide dismutase activity, K content were increased in plant. With increasing salinity to 100 mM NaCl, proline, malondialdehyde and H₂O₂ content were increased. Se, Na content and K/Na ratio in the second experiment was influenced by the interaction effects of salinity and foliar spray. At the second experiment, the top amount of K/Na ratio were recorded at NaCl₀ × 1.5 and 3 mgL^-1 Se spray. The top amounts of Na were recorded at NaCl0 × no foliar application. The superoxide dismutase activity, malondialdehyde and K⁺ were responded to the individual effects of salinity and Se treatment. The highest amounts of total phenolic content was attained by (1.5 and 3 mgL^-1) nano Fe and Se treatment in both experiment. With salinity of 50 and 100 mM, the flavonoids contend was increased at both experiments. Foliar spray with 1.5 and 3 mgL^-1 Nano Fe and Se increased catalase activity in plants. 1.5 and 3 mgL^-1 Se and nano Fe foliar application reduced H₂O₂ content in plant at both experiment. GC/MS analysis revealed that β-citronellol (12.5-20.5%) was the major constituent with control treatment Citronelly formate (10.75-25.2%) were the dominant constituents of oil control plants. Β-Thujone (12.61%), trans-Rose oxide (2.85- 9 %) and the highest amounts of Aromadendrene (5.42 %) only recorded at control plants. Salinity stress and foliar spray had negative effects on α-Pinene biosynthesis and the highest amounts of α-Pinene was recorded in control plants. The top amounts of Geranyl formate (0.7-7.8 %) was recorded at NaCl₅₀ × 1.5 mgL^-1 Fe spray. Y- muurolene (0.4 – 4.06 %) biosynthesis increased at NaCl50 × 1.5 mgL^-1 Se.
Conclusion
 Salinity stress involves changes in metabolic processes and various physiological traits, controlled by salinity stress severity. In total, salinity had negative effects on the growth and physiological responses of plants, however, foliar treatment with Se and Fe improved some physiological traits of Pelargonium graveolens.

Abstract Introduction
 In recent years, the aggressive application of chemical fertilizers for agricultural production has endangered the health of soil, water, air, as well as crops, and has raised many concerns for the global environment and human health. In addition to the positive biological effects and modification of soil physical and chemical properties due to the gradual release of nutrients, organic fertilizers cause less pollution in the environment. Due to the significant role of medicinal and aromatic plants in different industries, it is important to increasing production of yield and secondary metabolite produced without the use of harmful chemical fertilizers. Fennel (Foeniculum vulgare Mill) is widely grown in arid and semi-arid regions and due to its economic importance and pharmaceutical industrial applications, it is one of the world’s most dimension medicinal plant. This plant has antiseptic, antispasmodic, antiinflammatory, diuretic, carminative and analgesic effects and is effective in gastrointestinal disorder treatment. Moreover with its antioxidant and antiulcer properties, it is used to treat neurological disorders.
Materials and Methods
 This study was conducted to evaluate the effects of organic and biological fertilizers on the morpho-physiological and phytochemical properties of fennel (Foeniculum vulgar Miller). In this study, the impacts of vermicompost (0, 4, 8% in pot), animal manure (0, 7.5, 15% in pot) and mycorrhizal fungi (0, 1%) on physiological and biochemical properties of fennel in greenhouse conditions was evaluated. In order to extract the samples to measure biochemical factors, methanol 70% was used at a ratio of 5:1 (volume- weight). Determination of free radical scavenging was performed by using the DPPH test. The samples’ absorptions were read at a wavelength of 517 nm with Epoch Microplate Spectrophotometer, BioTek Instruments, Inc., USA. Measuring the total phenols was performed according to the Folin’s reagent method and the use of gallic acid as standard (purchased from the brand MERCK, Germany) by using a spectrophotometer at the wavelength of 765 nm. Total flavonoid content was measured using a spectrophotometer at a wavelength of 510 nm through a standard curve of quercetin from Sigma-Aldrich. The Essential oils were obtained from seeds by hydrodistillation for 3 h using a clevenger type device. The analyses of essential oil volatile components were determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Data were analyzed by using Duncan’s multiple range test (P< 0.05) by SAS, version 9.4 for Windows.
Results and Discussion
 The results of current investigation showed that organic and biological fertilizers improved the fennel yield and phytochemical properties such as the plant height, seed weight per plant, fresh and dry weight of roots and plants, content of total phenols and flavonoids, antioxidant activity, percentage of essential oil and root colonization. The highest plant height, number of flowers, umbrellas and seeds per plant and fresh and dry weight of roots were obtained after combined application of 8% in pot vermicompost, 15% in pot animal manure and application of mycorrhiza. According to the results, the highest amount of total flavonoids (177.66 mg/100g DW) and root colonization (35.8%) after of 8% in pot vermicompost + 15% in pot animal manure + mycorrhiza application was observed. The results also revealed that the highest fresh and dry weight of the plants (121.33 and 17.41 g, respectively) was obtained after application of mycorrhiza + 15% in pot animal manure. Application of mycorrhiza in combination with 15% in pot animal manure compared to other treatments caused a significant increase in total phenol content in aerial parts with 73.22 mg/100g DW. In addition, the highest amount of antioxidant activity (51%) was obtained after 8% in pot vermicompost + 15% in pot animal manure application. Application of organic and biological fertilizers significantly increased the 1000 seed weight and the percentage of essential oil in fennel. After 15% in pot animal manure treatment, the highest percentage of essential oil by 3.43% was recorded. In general, the highest percentages of essential oil components were related to (E)-Anethole (78.26%), Fenchone (7.15%), Limonene (6.12%) and Methyl chavicol (3.85%), respectively. The amount of (E)-Anethole as the essential oil predominant compound, in the control treatment was 66.92%. The application of mycorrhiza + 4% in pot vermicompost increased the content of (E) -Anethole in essential oil to 80.72%.
Conclusion
 In general, application of vermicompost, animal manure and mycorrhizal fungi improved the growth, biochemical and yield characteristics and essential oil yield of fennel in greenhouse conditions. These fertilizers increased plant yield by providing large amounts of required nutrients and affecting various aspects of root growth and development. Among them, the role of nitrogen may be more prominent due to its participation in protein synthesis and the role of iron in nitrogen fixation, photosynthesis and electron transfer.

Abstract Introduction
 UV-C (254-280 nm) and 280-320 nm) UV-B, UV-A (320-390nm) wavelengths are irradiated with three ultraviolet strips and have detrimental effects on the growth of a number of plants. Ultraviolet light is an important non-living factor that can stimulate the production of secondary metabolites, including antioxidant compounds in plants. Ozone depletion and its consequences, including direct UV radiation on the planet and its effects on crops and medicinal plants, are among the topics that have received very little study. Ultraviolet light in nature occurs only at low intensities, but if the inhibitory effect of the ozone layer in the stratosphere is significantly the result of nitrogen and hydrocarbon oxides the weaker the halogen, the higher its amount.
Materials and Methods
 Portulaca oleracea seeds were prepared by Pakan Isfahan Company. The aim of this study was the effect of ultraviolet rays at different levels (UV-C: 0, 100, 200, 300, 400, 500, 600, and 700 nm) on the activity of photosynthetic pigments and biochemical traits of portulaca oleracea in factorial in a completely randomized design with three replications. After transferring the seeds of portulaca oleracea, the healthy and uniform seeds of this plant were sterilized in 15% sodium hypochlorite solution for 154 minutes and then washed thoroughly with distilled water and placed in a petri dish for germination. Moisture was supplied through filter paper soaked in distilled water. The seeds were planted in pots filled with cocopeat and perlite evenly and watered for 20 days with a half-strength Hoagland solution. Plants were grown for 20 days at a temperature of 30 ± 2 ° C and a light period of 8.16 (light / dark, respectively). Plants for one week, every other day, and for 3 minutes each time by two fluorescent lamps with a wavelength of 260 nm exposed to ultraviolet C (at a distance of 30 cm from the UV light source with an intensity of 27 (w / m2) were located. The traits studied in this study included chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, phenol, flavonoids, and antioxidant activity. In this study, the effect of ultraviolet light on the activity of photosynthetic pigments and biochemical traits of portulaca oleracea was investigated factorially in a completely randomized design with three replications.
Results and Discussion
 The results of the mean comparison showed that the UV treatment of chlorophyll a, b, total chlorophyll, carotenoid of portulaca oleracea was reduced compared to the control; However, UV treatment of portulaca oleracea significantly increased phenol, flavonoids, and antioxidants compared to the control. The effect of different doses of ultraviolet rays on phenol and portulaca oleracea antioxidants showed that the UV-C highest and lowest were 700 and 100 nm, respectively. Decreases in carotenoid content can result in either inhibition of pigment synthesis or their breakdown and degradation. The results of this report indicate significant changes in phenols and flavonoids as compounds it absorbed ultraviolet rays compared to control cells.
Conclusion
 It can be said that excessive exposure to radiation may affect chlorophyll levels by inhibiting chlorophyll biosynthesis or accelerating its degradation. Oxygen is an electron receptor in the electron transport system that produces energy from adenosine triphosphate (ATP) in the body. Under certain conditions, oxygen can be converted to a single electron, creating free radicals. When oxygen is converted to a single electron, it is called active oxygen (ROS). These free radicals cause oxidative stress in plants which oxidative stress leads to damage to macromolecules such as DNA, proteins and so on. Environmental stresses, including UV radiation, produce active oxygen species (ROS) such as hydrogen peroxide (H₂O₂), superoxide (O₂^-), and hydroxyl radicals (OH), which cause oxidative stress and cause damage to cells, such as DNA. And cause the destruction of these compounds. The plant contains compounds that act as active antioxidants and sweep away active oxygen. In the present study, the observed increase in phenols, flavonoids and antioxidants indicates an increase in the production of free radicals under ultraviolet radiation and shows that the production of these radicals is more than the plant's defense capacity and has caused damage to plant biological membranes. In summary, the application of controlled ultraviolet light stress can provide a new alternative strategy to increase the productivity of the portulaca oleracea plant. Modulating UV-C light in agricultural systems is a promising tool to increase crop production. 

Abstract Introduction: The tendency to produce aromatic and medicinal plants and the demand for natural products is increasing especially in the world. Ecological agriculture (Agroecology) of medicinal plants guarantees their quality and reduces the possibility of negative effects on their quality and yield. Evaluation of different plant nutrition systems is one of the most important principles in the production planning of medicinal plants in order to achieve high yield and quality of effective ingredients. Proper fertilizer management is one of the most important factors in agricultural production. Identification of fertilizers which are compatible with nature and are suitable for plant growth could have favorable effects on quantitative and qualitative indices of the plant. Organic fertilizers are genuine and risk-free products that could be suitable for agricultural sustainability. Soil organic matter improves fertility and water retention, provides proper ventilation, long-term storage of plant nutrients and microorganisms, so replacing chemical fertilizers with fertilizers such as vermicompost and biofertilizer can reduce the above-mentioned effects. Biofertilizers are one of the operations that is nowadays in accordance with the principles of sustainable agriculture for soil fertility. Biofertilizers include the compost of one or more types of useful soil organisms or as metabolic by-products of these organisms that are used to provide the plant with the nutrients it needs in an agroecosystem.
Materials and Methods: In order to investigate the effect of biochar, organic and biological fertilizers on the quantity and quality of Ocimum bacilicum L., a factorial experiment was done in a randomized complete block design with three replications. Experimental treatments included two levels of biochar (0 and 20 ton ha^-1) and five levels of fertilizers (vermicompost (10 ton ha^-1), Mycorrhiza, Azotobacter, Pseudomonas and no fertilizer application). Prior to planting sweet basil seed, biofertilizers and vermicompost were mixed with soil to the depth of 15 cm. Mycorrhizal fungi were mixed with seed. Azotobacter and Pseudomonas bacteria were also incubated with seeds (seed inoculated). It should be added that in this study no chemicals were used to control weeds and pests.
Results and Discussion: According to the results, the highest plant height and number of main branches were obtained in biochar application with vermicompost (49.37 cm and 7, respectively), which was significantly better than other treatments. The interaction effect of biochar and fertilizer had a significant effect on fresh and dry weight of leaf and stem. Mean comparison of treatments showed that the highest leaf and stem fresh weight were obtained in biochar + Pseudomonas application (792 and 876 g m^-2, respectively), which had no significant difference with biochar + vermicompost; and also, the maximum leaf dry weight and stem dry weight were obtained in biochar with Pseudomonas application (166 and 175 g m^-2, respectively). The interaction between biochar and fertilizer on phenol, flavonoids and antioxidant activity of basil showed a significant differences between treatments.
Conclusion: In general, the results showed that the use of biochar and biological and organic fertilizers could be effective in both the quality and quantity of sweet bail, where, the use of the bacterium Azobacter and Pseudomonas with biochar had the greatest effect on the quality and quantity of sweet bail. Finally, it could be concluded that the combined use of biochar with biological fertilizers had significant impacts on the quantitative and qualitative traits of sweet bail in ecological or low input agricultural.

Abstract Introduction: Saffron is an annual plant that grows based on underground organs of the plant as corms and can be used for several years under farming conditions. This plant is the main source of income for many farmers in rural areas of eastern Iran. Khorasan Razavi province with 76% of cultivation area and 74% of production has the first place in saffron production. Among the different cities of Khorasan Razavi province, Torbat Heydariyeh city with a cultivation area of about 8 thousand hectares out of 87 thousand hectares of the whole province has an area equivalent to about 10%. Contrary to the level of cultivation, the average yield in Khorasan Razavi province is 3.4 kg / ha, which is 0.22 kg / ha lower than the national average. Considering that the level of saffron that is increasing in many parts of the country and on the other hand, according to the long-term average statistics, its yield has decreased significantly. The need for continuous monitoring of planting level and yield is one of the most issues for managers and programs. This research was conducted using the information of referral letters issued for guaranteed purchase of saffron in the Torbat-e Heydariyeh Kadkan town to analyze and evaluate the performance of saffron in 2017 and 2019.
Materials and Methods: In order to study saffron cultivation and its yield in the Kadkan town, cultivation data and yield data in the years 2017 and 2019 were analyzed. Guaranteed purchase information of saffron was used to collect data. In 2017, 95 people (at the level of 132 hectares) and in 2019, 173 people (at the level of 257 hectares) of saffron farmers in the Kadkan town to deliver saffron to guaranteed shopping centers (Rural Cooperative Office of Torbat Heydariyeh) to Jihad Agricultural Center. They came to Torbat-e Heydarieh Kadkan and received a letter of introduction. The information of these referrals (area under cultivation, dry stigma yield, production rate, village name and amount of saffron delivered) was used to analyze saffron cultivation in Torbat-e Heydariyeh, Kadkan town in 2017 to 2019.
Results and Discussion: Based on the results of saffron yield in the Kadkan town in 2017 and 2019, 5.17 and 8.64 kg of dry stigma obtained, respectively. The amount of saffron delivered to shopping centers in 2017 and 2019 was 532 and 1270 kg, respectively. According to the results of saffron yield in 2017 compared to 2019 due to climatic and managerial conditions, has increased by 67%. Fitting of cultivation and yield data of 95 saffron farms in 2017 using a linear model showed that with increasing the area under saffron cultivation, yield decreases R = 0.26 **. Also in the polynomial model. Second degree, with increasing the area under cultivation to the level of five hectares, the yield decreased and since then showed a slight increasing trend (R = 0.26 **). Fitting of cultivation data and yield of 173 saffron farms in 2019 based on the second degree polynomial model R = 0.24 24 ** showed that with increasing the area under cultivation up to seven hectares, the yield has decreased and since then it has an increasing trend. In the third degree polynomial model R = 0.28**, like the second degree of yield, decreased to seven hectares and then increased and then was fixed. Considering that the cultivation area of the most farms in Kadkan town was between 0.1 and 2 hectares and farms up to two hectares in the villages of Kadkan townt, it is non-mechanized, therefore, in these farms, the management of smaller farms could be done more easily and the increase in yield for these farms was predictable.
Conclusion: According to the results of the present study, the yield of saffron in 2017 and 2016 was 5.16 and 8.64 kg / ha, respectively. Considering that the average yield of saffron in the country is 3.62 kg per hectare (Statistics of the Ministry of Jihad Agriculture, 2018), the yield of saffron in the Torbat-e-Heydariyeh Kadkan town can be considered as high yield in the country, which is probably due to climatic conditions and is managerial. 67% increase in yield in 2019 compared to 2017due to climatic reasons (increased rainfall) and management (nutrition, agriculture, training, irrigation, proper planting date, use of corms with appropriate weight, disinfection of corms at planting, Summer irrigation, weed control).

Abstract Introduction: Sweet basil (Ocimum basilicum L.) is an annual herbaceous plant from labiatae family. The amount and chemical composition of essential oil of sweet basil depends on genetics, growing season, environmental factors and plant growth stage. Nitrogen is one of the most important nutrients required by plants. This element plays an essential role in the synthesis of amino acids and proteins and is part of the structure of leaf chlorophyll and some plant hormones. Nitrogen application can significantly increase the growth and yield of medicinal plants in different climatic conditions and affect the quantitative and qualitative properties of essential oils. The results of various studies have shown that nitrogen significantly alters the amount of essential oils in basil. Despite the positive effect of nitrogen on improving plant growth and yield, excessive use of nitrogen fertilizer can have a negative effect on the absorption of other elements. On the other hand, high amounts of water-soluble nitrogen lead to groundwater pollution. Therefore, determining the appropriate amount of nitrogen fertilizer in proportion to the nutritional needs of crops, in addition to improving the quantity and quality of yield, reduces damage to agricultural systems and the environment. Therefore, the aim of the present study was to evaluate the effect of different amounts of nitrogen fertilizer on vegetative yield and quantitative and qualitative characteristics of essential oil of four basil cultivars and to introduce the best cultivar in Khorramabad climate.
Materials and Methods: This experiment was performed as a factorial split plot in time in a randomized complete block design with three replications during 2016 growing season in the Agricultural Research Station of Khorramabad. Experimental treatments included four sweet basil cultivars (Italian Large Leaf, Cinnamon, Sweet Thai and Mobarakeh), three levels of nitrogen fertilizer (0, 100 and 200 kg ha^-1 chemical nitrogen fertilizer) and three harvests. Nitrogen fertilizer (from urea source) was added to the plots in two stages (half of the fertilizer before seeds planting and the rest after the first harvest) based on the treatments. Basil plants were harvested three times at the beginning of flowering. Traits measured in this study included chlorophyll index, leaf/stem ratio, leaf dry weight, total plant dry weight, percentage and yield of essential oil and determination of chemical composition of essential oil. To extract the essential oil, water distillation method and Clevenger apparatus were used. To determine the main constituents of essential oil, all treatments related to a given repetition were chosen in second harvest were used. Gas chromatography with mass spectrometer was used to identify the compounds of basil essential oil. Analysis of variance of data was done using SAS ver. 9 and mean comparison was performed based on the Duncan's multiple range test at 5% probability level using MSTAT-C software. Figures were drawn by excel software.
Results and Discussion: The results of the present research showed that the highest leaf/stem ratio (1.8) was obtained from applying 100 and 200 kg ha^-1 of urea fertilizer in Italian Large Leaf cultivar in the first harvest. Among the studied basil cultivars, Italian Large Leaf cultivar had the highest leaf dry weight, total dry weight, percentage of essential oil and essential oil yield. The maximum leaf chlorophyll index was related to Sweet Thai and Cinnamon cultivars and the minimum chlorophyll index, percentage of essential oil and essential oil yield was related to Mobarakeh cultivar. Consumption of urea fertilizer was associated with a significant improvement in vegetative growth and as a result, basil yield increased. Although the essential oil percentage of basil cultivars under control treatment was higher than plants that were fed with nitrogen fertilizer, but the highest essential oil yield was obtained from application of 100 kg ha^-1 urea fertilizer, which shows the greater effect of dry yield on essential oil yield compared to the percentage of essential oil. In all studied traits, the maximum value was related to the second harvest and the minimum amount (except the essential oil percentage) was allocated to the first harvest. In chemical analysis of essential oils obtained from young leaves and shoots of basil cultivars under different fertilization treatments, 29 to 35 compounds were identified. The maximum concentration of major constituents of essential oils (except 1-8-cineol, methyl cinnamate and methyl chavicol) was related to the control treatment (no fertilizer application).
Conclusion: Since there was no significant difference between the levels of 100 and 200 kg ha^-1 of urea in terms of total dry weight and the highest essential oil yield was obtained from the treatment of 100 kg ha^-1 of urea fertilizer, Italian Large Leaf cultivar and consumption of 100 kg ha^-1 of urea fertilizer can be used in environmental conditions similar to Khorramabad.
 

Abstract Introduction: Nowadays, due to the decrease in rainfall and groundwater level, the cultivation of crops with low water requirements should be given priority. Different regions of Iran, especially the region of East and West Azerbaijan, have faced a decrease in rainfall in recent years, compared to previous years. Saffron could have relatively stable production in these areas due to low water demand and suitable economic efficiency. Special properties of saffron such as low water requirement, irrigation in non-critical times, water requirement of other plants, possible operation of farms for several years after one planting, ease of transportation and storage of the product, possibility of high employment, possibility of cultivation in areas that lack industrial talents and limited agricultural water, having medicinal properties and also, suitable domestic and foreign sales market has made this plant for cultivation. On the other hand, saffron cultivation in the Iran could increase employment and non-oil exports.If we pay attention to its production and processing processes, it could provide a significant currency to the country. Today the cultivation of saffron is under development in areas such as Azerbaijan. On the other hand, due to the harmful effects of the using synthetic antioxidants in the food and pharmaceutical industries, special attention has been paid for using of natural antioxidants. Considering the importance of compounds in saffron quality and the effect of climatic conditions in different years on the amount of secondary metabolites and antioxidant properties of this valuable plant, the present experiment were evaluated the yield and quality of saffron and compared antioxidant activity of different parts of saffron during two cropping years.
Materials and Methods: The effect of climate of Marand city of East Azarbaijan province in different years on quality and antioxidant characteristics of different parts of saffron was investigated in this region. So, the climatic factors governing this region during two consecutive years of 2014 and 2015 in terms of temperature, rainfall and humidity were studied using meteorological data. Saffron yield in the region were obtained by using a questionnaire from saffron producers in the region. Meanwhile, the amount of crocin, picocrocin and safranal and the antioxidant activity of different parts of saffron, including stigma, style, stamen and petals, were examined.
Results and Discussion: The results showed that the Marand city was classified as semi-arid in accordance the amount of crocin metabolites in 2014 (maximum: 306 mg/g in the stigma), picocrocin in 2015 (102.15 mg/g in the stigma), and Safranal in 2015 (highest: 49.95 mg/g in saffron petals) and the antioxidant activity of saffron and saffron petals were the highest in 2014 (30.43% and 88.32%, respectively). The results showed that the quality of different parts of saffron varied in different years. Due to the quality of different parts of saffron in different years, different parts could be used for exploitation.
Conclusion: The amount of active ingredients in the plant were not constant at all and varied according to the growth and climatic conditions and harvest time. Changes in the amount of active ingredients in the plant over consecutive years or even hours a day emphasized the importance of collecting the medicinal plant when the plant contained the maximum amount of active ingredient. The quality of saffron depended on the amount of crocin, picrocrocin and safranal compounds and antioxidant activity. These compounds varied in different organs of saffron (stigma, style, stamen‎ and petals) and over consecutive years. Bonab of Marand ‎region of East Azerbaijan is suitable for saffron cultivation due to the climate change. The quality of different saffron organs were different in consecutive years of multi-year cultivation. The highest amount of crocin in the first year of cultivation in the stigma and its antioxidant activity in the stigma and petals were the highest and in the following year the amount of picrocrocin in the stigma and safranal in the petals were the highest. Therefore, different metabolites could be harvested according to the need in the maximum number of years.

Abstract Introduction: Biochar is a carbonaceous substance obtained from heating plant residues and wastes in an oxygen-containing medium with or without oxygen. Thermal decomposition of biomass in an oxygen-free medium is called thermophilicity (pyrolysis). Temperature is one of the factors influencing the characteristics of biochar. One of the objectives of this experiment is to investigate the effect of different temperatures on the biochar characteristics of cattle manure. The use of biochar as a soil conditioner and source of organic carbon in agricultural soils with minimal environmental damage is considered. Marigold is an annual plant that is used in industry and pharmacy in addition to food. Another aim of this experiment is to investigate the effect of biochar use from different temperatures on marigold under salinity stress.
Materials and Methods: For biochar preparation, after collecting cattle manure from Bardsir farms, air drying and sieving were used for pyrolysis process for four hours at different temperatures (300, 400, 500, 600 °C). Then pH, EC, carbon stability, ash and biochar performance were measured. In order to evaluate the effects of biochar resulting from different heat-treated temperatures on salinity tolerance of marigold, a factorial experiment was conducted in a completely randomized design in the greenhouse. The two factors studied included salinity levels (0, 4, 8 and 12 dS.m^-1) and biochar resulting from different thermocouple temperatures (0, 300, 400, 500 and 600 °C). The biochar rate was considered to be 20%. One month after salinity treatment, seedlings were evaluated for osmotic metabolites activity and growth characteristics of marigold seedlings.
Results and Discussion: The results of ANOVA showed that all biochar properties were significantly affected by temperature factor. With increasing the pyrolysis temperature from 300 to 600 °C, pH and EC increased by 16.29% and 60.37%, respectively, and the ash content increased by 1.5 folds, but biochar performance and bulk density decreased by 52.28% and 48.1%, respectively. The highest carbon stability was observed at 500 °C, which increased by 20% compared to 300 °C. The results showed a significant negative effect of salinity stress on stem height, number and area of marigold leaves, so that with increasing salinity to 12 dS.m^-1, 31.09, 17.28 and 45.7% decrease were observed in these traits, respectively. The physiological characteristics of marigold were significantly affected by the simple and interaction effects of salinity and biochar stress. In salinity treatments (0, 4, 8 and 12 dS.m^-1) with increasing pyrolysis temperature from 300 to 600 °C 2.2, 2.04, 1.97 and 1.92 folds increase in leaf potassium concentration and 1.54, 2.26, 3.00 and 2.45 folds less than the control treatment in the amount of leaf proline was observed,  respectively. The activities of catalase, ascorbate peroxidase and guaiacol peroxidase enzymes were also significantly affected by the interaction of salinity stress and heat temperature. The highest enzyme activity in biochar was from 600 °C, which increased up to 8 dS.m^-1 for catalase and up to 4 dS.m^-1 for ascorbate peroxidase and guaiacol peroxidase.
Conclusion: In general, biochar salinity is its most important undesirable properties, which increases with increasing pyrolysis temperature, so the recommendation of biochar application in saline soils requires further studies. In the present study, the use of biochar under salinity stress did not have a significant positive effect on the development of marigold resistance and salinity stress tolerance.

Abstract Introduction: In fact, drought is stress that restricts the plant photosynthesis and also it causes of chlorophyll content changes and damage to photosynthetic structures. One of the important reasons that environmental stresses such as drought reduce the growth and photosynthesis ability of the plant is a disturbance in the balance between production and removal of free oxygen radicals. Transpiration is a necessary process for photosynthesis and growth of plants but depending on the conditions that may be harmful in some cases. Therefore, the use of anti-transpirant can be one of the most effective methods for reducing the amount of water lost through transpiration and adjustment the reduction of the yield due to water deficiency in arid and semi-arid regions. Climate change happened on earth and the intensification of stresses caused by it, especially drought stress in arid and semi-arid regions such as Iran. Therefore, finding strategies that can reduce the effects of water shortages on plant growth and yield can be very important. The aim of the present study was to investigate the effect of irrigation regimes and application of different concentrations of tragacanth (naturally dried exudate from some Astragalus species) on black cumin plant.   
Materials and Methods: This research was carried out in a factorial experiment based on completely randomized design with three replications in a greenhouse of the Agriculture College of Kurdistan University in 2018. The experimental factors were including irrigation at three levels of 100% (full irrigation), 70% (mild drought stress), and 40% (severe drought stress) of field capacity of soil and spraying with tragacanth extract at six concentrations of 0, 1.25, 2.5, 5, 7.5, and 10 g/L. Spraying of this material was done using a back sprayer (Shark model) with a constant pressure of 2.4 bar and a volume of 250 liters of water per hectare., The normality test was performed using the Mini Tab software, before the data were analyzed. After ensuring the normality of data, analysis of variance was performed using SAS ver. 9.3. LSD (Least significant difference) was used to compare the mean of treatments. The graphs are drawn using Excel software.   
Results and Discussion: The results showed that increased drought stress intensity (irrigation reduction) led to the reduced leaf relative water content, Total chlorophyll content, efficiency of photosystem II, plant height, number of capsules per plant, mean number of seeds per plant, biological yield and grain yield. The positive effects of tragacanth consumption on reducing and modifying the effects of drought stress on different levels of irrigation and different concentrations of tragacanth were different. In the present study, under full irrigation conditions, lower concentrations of tragacanth were useful, while in drought stress conditions, higher concentrations of tragacanth (except 10 g/L) were useful. In full irrigation, the concentration of 1.25 g/L was positive for all studied traits. In mild drought stress, the use of higher concentrations of tragacanth up to 5 g/L had the best effect and more concentrations resulted in a reverse effect on studied traits. In severe drought stress, the use of more concentrations of tragacanth extract was beneficial and improved the studied traits up to 7.5 g/L, but 10 g/L had a negative effect on these traits.
Conclusion: The results of this study indicated that the different effects of various concentrations of tragacanth material in different levels of irrigation on studied traits of black cumin. Therefore, it can be concluded that the application of different concentrations of tragacanth gum was completely dependent on the plant's water status. Therefore, using higher concentrations of tragacanth gum in drought stress conditions had a more positive effect on the plant, and vice versa, using a lower concentration of this material was useful in full irrigation. The effect of tragacanth gum on reducing and modifying the effects of drought stress in different plants requires further studies and extensive research. Tragacanth gum can be introduced as a new anti-transpirant agent with natural origin and its application can be useful and recommended in areas exposed to drought stress.
 

Abstract Introduction: St. John’s wort (Hypericum perforatum L.) is a medicinal plant which used mainly in treatment of mild depression, neurological disorders and has been recently shown to have anticancer potential. The principle medicinal components of St. John’s wort are hypericin, pseudohypericin, and hyperforin. Light is one of the most important environmental factors affecting plant growth, survival, reproduction and distribution. The light quality, light intensity, duration and photoperiod directly affect plant growth. Light quality refers to the color or wavelength reaching the plant's surface. A prism (or raindrops) can divide sunlight into respective colors of red, orange, yellow, green, blue, indigo and violet. Red and blue have the greatest impact on plant growth. Green light is least effective (the reflection of green light gives the green color to plants). Blue light is primarily responsible for vegetative leaf growth. The principle objective of the current study was to evaluate the effects of different spectral quality including red, blue, green and white on the growth factors and production of hypericin.
Materials and Methods: This experiment was conducted on the basis of Completely Randomized Design with four treatments and 10 replications in the growth chamber in the Department of Horticulture, Ferdowsi University of Mashhad (FUM), Iran. In this study, seeds were obtained from the research greenhouse of FUM. Seeds after soaking in running water for 24 hours were planted in small pots (250g). After the seedlings have reached to height of 25cm, each 10 pots were put inside the boxes (20×30cm) made of colored filters. Experiment continued in a growth chamber with day and night temperature 25 and 21°C, respectively, relative humidity 45%, 16 hours of light with the intensity of 1000 lux and 8 hours of darkness for 50 days. Then morphological parameters including plant height, number of stems, number of leaves, number and length of internodes, fresh and dry weight of shoot and root were measured. To count the number of black nodules, the upper, middle and lower parts of seedling were evaluated individually. Hypericin content of the H. perforatum plantlets were measured according to the previous work of Azizi & Omidbaigi, 2002. Data were analyzed statistically by using SAS and Excel software. The significant differences between means were assessed by Tukeyʼs test at P < 0.05.
Results and Discussion: The results showed that morphological parameters including plant height, leaf number, internode length, root fresh weight, dry weight of stem and root were affected significantly by light treatments. Minimum and maximum of plant height was related to white and red lights, respectively. Increasing plant height under the influence of red light was due to the variation in levels of growth regulators. Red and blue light by changing of the GA hormone level in the plant and affected elongation of plant stem. Minimum and maximum of leaf number was related to blue and white light respectively. Also, other morphological traits including internode length, fresh and dry weights of stem and root showed significant differences. Internode length for white light was less than red, green and blue light. Maximum of the fresh and dry weight of shoot and root of seedlings was observed under white light. Results suggest that photosynthetic compounds move in plant under the influence of light quality. Also the number of black nodules in three different parts of plant and hypericin content were compared in plantlets under the effect of light quality. Results analysis also confirmed that different lights had the significant impact on the number of black nodules in upper and middle leaves of H. Perforatum seedlings. Seedlings treated with the red light had the highest number of black nodules in the middle section of H. perforatum. In the top third of St. John’s wort seedlings, red, blue and green light was inducted the highest number of black nodules formation than white light. The highest level of hypericin was related to red, white, blue and green lights, respectively. The number of black nodules in the plant and the hypericin content have positive correlation. It seems that in the seedlings treated with the red light, carbohydrates made from photosynthesis most used in biosynthesis of secondary metabolites than plant growth. In fact, carbon allelochemical compounds such as terpenes and phenolics have such metabolism direction to explain the increasing in secondary metabolites.
Conclusion: Different light spectra affects plant hormones levels and with alteration in the primary and secondary metabolites lead to a change in the morphological and biochemical traits of plant. In general, it can commented that the quantity and quality of light is able to affect the growth and the active metabolites of medicinal plants and using red and white mixture of light during seedling growth period have an effective role on generation of more strong seedlings with higher potential production of active ingredients.

Abstract Introduction: In the last decades, human activities have had adverse effects on the atmosphere and the stratospheric ozone layer, resulting in an increase in the ultraviolet radiation on the ground, especially in highlands. Among living organisms, plants are the most exposed to ultraviolet rays due to their high and unavoidable need to light for photosynthesis, and are therefore more vulnerable to them. Plants show different responses to ambient UV radiation. The response of plants to ultraviolet light is manifested in two general ways, including tolerating the destructive effects of this radiation or/and avoiding it. The present study was conducted to evaluate the effect of ultraviolet light on growth, morphological and phenological characteristics of three cornflower cultivars under greenhouse conditions in 2018.
Materials and Methods: The experiment was performed as a split plot in a completely randomized design. Ultraviolet light was considered as the first factor in four levels (including: control, ultraviolet –A radiation, ultraviolet -B radiation and ultraviolet A + B radiations) and three cornflower cultivars (including: ‘Kornblume pink’, ‘Kornblume rot’ and ‘Kornblume blau’) as the second factor. The UV treatment was applied by lamps made by Q-Lab Co, USA. It should be noted that the 40-watt lamps used in this study were broadband and had the highest compliance with ultraviolet B (in the case of UV-B lamps) and ultraviolet A (in the case of UV-A lamps) received from the sun on the ground. So they provided the best possible simulation. During the growth period of plants, phenological traits were recorded and morphological traits and biomass traits were measured at the end of the experiment.
Results and Discussion: The results showed that UV-B radiation and simultaneous application of UV-A and UV-B radiations resulted in the reduction of the most morphological traits and yield traits including plant height, internode length, leaf width, leaf area, flowering stem length, plant fresh and dry weight, leaf dry weight, flower dry weight and number of flowers. However, flower yield was not affected by ultraviolet radiations. UV-A treatment reduced the flowering stem length and fresh and dry weight of plant in compared to the control treatment, but it had no significant effect on plant height, leaf width, leaf dry weight, flower dry weight and number of flowers. Plants response to ultraviolet radiation is very different. In many species, it has been observed that UV-A does not have a negative effect on plant growth, while, UV-B reduced the growth and yield of plants. It seems that the main reason for the reduction of plant growth and production is prevention of cell division caused by ultraviolet radiation. Degradation of plant pigments (chlorophyll) is also one of the main reason of photosynthesis decrease led to plant growth and yield reduction. The results of the present study showed that the application of UV-A reduced the number of days until the emersion of the first flower bud and the number of days until the opening of the first flower in cornflower cultivars compared to the control. UV-B treatment forced cornflowers to earlier flowering than UV-A. However, the fastest entry into the reproductive and flowering phase of cornflower cultivars was observed with the simultaneous application of UV-A and B radiations. Plants mechanisms against environmental stresses mainly depend on their origin and genetic factors. These mechanisms include three main strategies including “avoidance”, “tolerance” and “escaping”. One of the most important ways to reduce the life cycle is early flowering. It seems that the process of early flowering and completing the growth in cornflower species is a kind of stress escaping under ultraviolet radiation stress.
Conclusion: In this study, ultraviolet radiation reduced the growth and development of all three species of cornflowers. However, UV-A treatment showed the least negative effect on flower yield of plants. On the contrary, UV-B radiation and simultaneous application of UV-A and UV-B radiations reduced the growth and development of cornflowers, but did not have any significant negative effect on the flower yield (as the main useable organ of plant). Therefore, it seems that the ultraviolet radiation can be considered as a positive factor due to its positive effects on the production of secondary metabolites and early flowering and lack of significant negative effects on plant flower yield. Finally, ‘Kornblume pink’ cultivar, with higher flower yield and earlier flowering, is more suitable for cultivation than other cultivars.

Abstract Introduction: The harvest time and type of plant part have important roles in obtaining maximum amounts of active substances from medicinal plants. Medicinal plants vary in terms of phenological stages and maturity and each medicinal plant can be evaluated separately in research. Determining the exact time of harvest and selecting a plant organ for maximum yield of secondary metabolites can be very important and economically effective. Othroj-Saghir (Citrus medica var. medica Proper) or Othroje-Kabir (Citrus medica var. macrocarpa) is one of the most important citrus species. The southern provinces of Iran, especially the southern cities of Fars province, are the largest areas in which this species is cultivated. In addition to fruit juice, other parts of the fruit especially the flavedo, can be used for medicinal purposes and in food industries. In this study, for the first time, some physical and biochemical changes of different parts of Citrus medica var medica fruits were evaluated during fruit ripening. Also, some active substances (i.e. essential oil content, flavonoid components, etc.) of the flavedo were measured as the most important medicinal parts of the fruit through different stages of ripening.
Materials and Methods: In this study, the effects of fruit ripening on the biochemical properties of different parts of Citron fruit were evaluated. A factorial experiment was set up according to a randomized complete block design (RCBD) with two factors and four replications. The first factor included four levels: different stages of fruit maturity (green mature, intermediate, yellow ripe and over ripe stage). The second factor had four levels: the different parts of the Citron fruit (i.e. outer skin or flavedo, inner skin or albedo, pulp and juice). The most important measured traits were flavon and flavonols, total flavonoids, total phenolic compounds and antioxidant activity. Physical changes in different parts of the fruit (fresh and dry weight of flavedo and albedo, fresh weight of fruit, fruit diameter and height of fruit, etc.) were measured.
Assessments also carried out to identify several features of fruit juice such as acidity, total soluble solids (TSS), titrable acidity (TA) and vitamin C during fruit ripening. Chemical measurements were aimed at determining the most important phytochemical compounds of the flavedo section during fruit ripening. These features included the essential oil percentage and yield, chlorophyll content and polyphenols constituents (rutin, trans-ferulic acid, hesperidin, hesperetin and quercetin by HPLC).
Results and Discussion: The results showed that the fruit maturity stage significantly affected most of the studied traits. The highest amounts of flavon and flavonols (0.377 mg quercetin/g dry weight) and total flavonoids (16.38 mg quercetin/g dry weight) were measured in the flavedo at the over ripe stage. The antioxidant activity initially increased during fruit ripening, but it decreased slightly (75.0%) from the yellow stage to the over ripe stage. The lowest rate of antioxidant activity (53.6%) was observed in the green stage and the highest rate (78.4%) was measured in the yellow ripe stage. The highest amounts of antioxidant activity (83.3% and 73.8%) were measured in the albedo and flavedo samples, respectively, and the lowest amount (54.1%) was recorded in the pulp section. The highest amount of flavedo essential oil (2.37%v/w) was measured in intermediate stage. The chlorophyll content with maturity progress was decreased. Progress in fruit maturity was reduced the most components of polyphenols. The maximum amount of hesperidin, as an important phenolic component, was identified in the peel of Citron fruit (1.86 mg/g dry weight) at the green mature stage. Its amount decreased through the stages of maturity, so that the lowest amount (0.68 mg/g dry weight) was measured at the over ripe stage.
Conclusion: In general, the stage of maturity and plant part had important effects on the amount of biochemical traits. The flavedo part of Citron fruit showed superior medicinal properties. Different active substances react variedly during maturity and so the preferable composition should be harvested according to the desired conditions. The best stages to reach maximum essential oil percentage and polyphenol components are the early stages of maturity (i.e. green mature and intermediate stages).