Research Article
Mehdi Aryan; Mehdi Khojastehpour; Mahmood Reza Golzarian
Abstract
Introduction: Cucumis melo L. is a plant from the Cucurbitaceae family. Many researchers consider the early habitat of this plant to be African, which has gradually become domesticated in Iran and Egypt. Melon fruit has undergone many physical and chemical changes during the growing season from the flowering ...
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Introduction: Cucumis melo L. is a plant from the Cucurbitaceae family. Many researchers consider the early habitat of this plant to be African, which has gradually become domesticated in Iran and Egypt. Melon fruit has undergone many physical and chemical changes during the growing season from the flowering to the maturity. Since these changes have a direct impact on the fruitfulness of fruit juices, the knowledge of process of these changes can be helpful in farm management include fertilizers, irrigation, and so on. The use of X-ray radiation in study of fruits quality and other agricultural products has always been of interest to researchers. The purpose of this study is to provide a method that is able to inspect melon fruits in non-destructive and accurate.
Materials and Methods: In this research, two local populations of melon, ‘Ghasri’ and ‘Khatooni’, were used. In summer of 2017, the specimens were collected from two adjacent farms from Abrvan village with a geographical position of 59° 58′ 40″ and 36° 4′ 34″ and an approximate height of 930 m above sea level. With the advent of flowers, a number of them were plated and harvested in 15, 30 and 45 days after flowering. In the ‘Khatooni’ population, as the fruit reaches its full maturity earlier than the ‘Ghasri’, the harvesting time was considered 40 days after flowering. In this research, the Optima-CT540, CT-Scan made by GE Healthcare was used. This device can display up to 16 cuts per round. All selected melons are in the direction of longitudinal diameter, which is the largest diameter of the fruit and entered into the device on the head. The images were loaded in the Microview medical software (v. 21), and the volume of seed cavity and the total volume of melon fruit were calculated. In this research, the quantitative change factor was a percentage of cavity volume percentage (Cavity) along with factors such as moisture content percentage, soluble solids, volumetric weight, and pH, with simultaneously changing two qualitative variables of "Melon variety " (with two levels of ‘Ghasri’ and ‘Khatooni’). The nominal variable "harvesting stage" (with three levels) was performed using multivariate analysis of variance (MANOVA) and combined with Duncan's multiple range test using SPSS (v. 24) software. Normality of data was also evaluated by the SPSS software. Data was analyzed at 1% of probability level.
Results and Discussion: The results of this study showed that as the fruit grows, the volume of seed cavity increases, but the rate of this increase is lower than the increase in total fruit volume. This causes the percentage of seed cavity to decline during the growing season. Meanwhile, there is a decrease in the amount of ‘Ghasri’, which has a larger lateral mass compared to the ‘Khatooni’. By decreasing the volume of seed cavity during the growth period, the percentage of moisture content and specific gravity of fruit is reduced. The moisture content decreased from 94.04 to 90.61% in ‘Ghasri’ and from 93.52 to 89.12% in ‘Khatooni’, which showed a significant difference (p ≤ 0.01) at each stage. The percentage of soluble solids increased from a minimum of 4.97% in the type of ‘Khatooni’ to a maximum of 12.74% in the ‘Ghasri’ type during the growing season, and the pH value in this experiment was from a minimum of 4.53 in the type of ‘Khatooni’ to the maximum value of 5.98 has changed in ‘Ghasri’.
Conclusion: The results of this study showed correlation between the dependent variables of moisture content, the percentage of soluble solids, volumetric weight and pH with independent variable of seed cavity volume in ‘Ghasri’ population. In addition, the apparent impact of two harvesting stages and the variety on other factors was evident. In the meantime, the use of X-Ray Computed Tomography Techniques as a non-destructive method to observe the internal variation of the fruit has helped to study the intrinsic properties of melon fruit.
Research Article
Gholamhossein Davarynejad; Mina Nurzadehnamaghi; Ali Momen
Abstract
Introduction: Pistachio (Pistacia vera L.) is an important horticultural crop that has high economic value. Pistachio trees display some physiological disorders including abscission of inflorescence buds, fruit abscission, blankness, non-splitting, early splitting and deformation of nuts. Unfavorable ...
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Introduction: Pistachio (Pistacia vera L.) is an important horticultural crop that has high economic value. Pistachio trees display some physiological disorders including abscission of inflorescence buds, fruit abscission, blankness, non-splitting, early splitting and deformation of nuts. Unfavorable environmental conditions in most pistachio orchards and inadequate nutrition during the flowering time and after flowering has increased these problems in recent years. Polyamines such as putrescine, spermine and spermidine are some low molecular weight polycationic compounds that have been shown to play an important role as growth regulators in different stages of growth and development of buds, flowers and fruits and resistant plants to abiotic and biotic stress. Therefore, the objective of this study was to investigate the influence of polyamines in water scarcity condition on growth, nut traits and yield of ‘Akbari’ pistachio trees. Materials and Methods: The study was carried out in growing season 2016 in a pistachio orchard (Pistacia vera L. cv Akbari) located in Feyzabad, Mahvelat, Khorasan Province, Iran (34° 40´ N latitude, 58° 25´ E longitude, and around 1253 m above sea level). The climate of the experimental area was arid and semi-arid. The mean annual precipitation was about 171 mm. The irrigation of orchard trees was at 36-day intervals. The experiment was conducted as split plot based on a randomized complete block design with three replications and seven treatments including polyamines spray of Putrescine (Put), Spermine (Spm) and Spermidine (Spd) at concentrations of zero (control), 0.1 and 1 mM on “on” and “off” pistachio trees cultivar Akbari at two-time stages full bloom (FB) and two weeks after full bloom (2WAFB). Leaf chlorophyll index was recorded using the chlorophyll meter (SPAD-502, Konica Minolta, Japan). Leaf area from fully expanded leaves was measured by Digital Leaf Area Meter (LI-3100c). The length and diameter of current-year shoots were measured at harvest time. The percentage of flower bud abscission and fruit abscission were calculated on marked shoots. The yield was calculated by weighting the total dried split nuts separated from each shoot. The data were subjected to analysis of variances (ANOVA) using the SAS software (SAS version 9.1). Difference between means was compared using the least significant difference test (LSD) at 5% level (p ≤ 0.05). Results and Discussion: Results showed that among the treatments, Put (0.1 and 1 mM) and Spm (0.1 mM) applied in the “on” trees significantly increased leaf chlorophyll index. Also, Put spray at two weeks after full bloom indicated better results in increase of length shoot in ‘on’ trees. All of the polyamines reduced fruit abscission in the “on” trees however, Put at 0.1 and 1 mM concentrations with 11.3 and 11.1% was more effective in decreasing the percentage of fruit abscission compared to other treatments. Fruit abscission of pistachio is assumed to be related to improper fertilization, the dominance of fruits in a cluster or abnormalities of reproductive organs. Polyamines have been suggested to improve fertilization, and subsequent embryo and fruit development. It also has been reported that common precursor of S-adenosylmethionine (SAM) needed for synthesizing both of PAs and ethylene. Thus, it seems that polyamines reduce the abscission of fruits by the improvement of embryo growth and development or by antagonism with ethylene, possibly by competing for S-adenosylmethionine (SAM). Our study indicated that all of the polyamines decreased the percentage of blank nuts in the “off” trees especially two weeks after full bloom. The results showed that Put (0.1 and 1 mM) and Spd (0.1 mM) were very effective in increasing number of nuts per cluster. Number of nuts per 100 g, split nuts, and kernel percentage did not differ significantly among treatments. Yield variations were not significantly affected by polyamines in in the “off” trees, but in ‘on’ trees, polyamines of Put, Spm and Spd at 0.1 mM concentration by 46.2, 14.6 and 15.2% and at 1 mM concentration by 38.7, 24.7 and 19.9% increased yield compared to control, respectively. Given to correlation results, the positive effect of polyamines on yield improvement in ‘on’ trees was mainly due to the prevention from fruit abscission and enhancement no. of nuts per cluster. Conclusion: Results showed that application of polyamines treatments in ‘off’ trees only on blank nuts and in ‘on’ trees on leaf chlorophyll index, fruit abscission, No. of nuts per cluster and yield was effected. Foliar application of polyamines was more effective in improving traits of shoot length, leaf area and blank nuts two weeks after full bloom compared to full bloom. The results of this study showed that these plant growth regulators, especially putrescine, had the potential to improve growth, yield and reduce physiological problems of pistachio under unfavorable environmental conditions.
Research Article
Mohsen Seilsepour
Abstract
Introduction: Garlic (Allium sativum L) is the second most commonly used herb of alliums after onions. This plant has significant effects on lowering blood pressure, preventing atherosclerosis, reducing blood cholesterol and triglyceride and inhibiting platelet aggregation. In recent years, the increase ...
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Introduction: Garlic (Allium sativum L) is the second most commonly used herb of alliums after onions. This plant has significant effects on lowering blood pressure, preventing atherosclerosis, reducing blood cholesterol and triglyceride and inhibiting platelet aggregation. In recent years, the increase in the yield of this product has been of interest to manufacturers of this product with respect to the preservation of qualitative characteristics, including the maximum content of nitrate. It has been shown that the absorption of nutrients in the soil affects the yield and yield components of the plant. In this regard, the timely and adequate supply of nutrients such as sulfur and nitrogen has a special role in promoting quantitative and qualitative characteristics of garlic. Material and Methods: In order to study the effects of nitrogen and sulfur consumption on quantitative and qualitative traits of garlic, this study was conducted with 12 treatments and three replications in the form of a split plot design in two years in Agricultural Research Center of Agricultural and Natural Resources of Tehran Province which located in Varamin in Iran. Nitrogen factor was considered at four levels (0, 100, 200 and 300 kg ha-1) and sulfur at three levels (0, 500 and 1000 kg ha-1 with inoculation of Thiobacillus). Before planting, soil samples were taken from the experimental site and physical and chemical characteristics including texture, reaction, organic carbon, lime, nitrogen, phosphorus and potassium, and iron, manganese, copper, zinc and boron were measured. Dry matter yield, number of bulbs per garlic, single plant weight, garlic weight, plant height, leaf number per plant and leaf area were recorded at the end of experiment. Garlic nitrate content and nutrient concentration in garlic leaves were also measured. Data obtained were analyzed statistically using SAS software. Results and Discussion: The effects of nitrogen and sulfur on the yield of garlic cloves, number of bulbs in cloves, cloves weights, bulbs weights, plant height, leaf area and bulb nitrate were significant as all these traits were improved. Application of 1000 kg.ha-1 of sulfur increased the garlic cloves yield by 31% compared to the control. Nitrogen consumption up to 200 kg.ha-1 increased garlic cloves yield by 58% compared to the control. The highest economic yield of garlic cloves was obtained by 1000 kg.ha-1 sulfur and 200 kg.ha-1 nitrogen, which was 104% more than control treatment. Data also showed that the effects of sulfur and nitrogen and the interaction of sulfur and nitrogen on the leaf area of the garlic plant were significant. Consumption of 1000 kg.ha-1of sulfur increased the leaf area of the garlic plant by 42% compared to the control. Nitrogen consumption up to 200 kg.ha-1 increased the leaf area of garlic plant by 39.3% compared to the control. The highest leaf area of garlic plant was obtained from 1000 kg.ha-1sulfur and 200 kg.ha-1nitrogen, which was 104% higher than control. Increase of the growth and yield of garlic was attributed to the main role of nitrogen in increasing meristematic activity, cell division, prolongation of the cell. Sulfur is one of the essential nutrients of the plant, and without sulfur, the plant does not grow and function properly. Sulfur is the fourth essential element after nitrogen, potassium and phosphorus for garlic. This element is needed in production of amine acids, such as methionine and cysteine, which are essential for the production of vitamin A, and the activation of certain enzymes. The results of studies have shown that amino acids directly or indirectly affect the physiological activity of the plant, and positively affect the growth, increase in yield and increase plant tolerance to environmental stresses. The soil reaction was affected by sulfur consumption and decreased. There was a negative correlation between soil reaction as a dependent variable (Y) and consumed sulfur as an independent variable (X), which correlated with linear relation with correlation coefficient of 0.98. Data showed that use of 1000 kg.ha-1of sulfur reduced soil reaction from 7.49 to 7.26 and increased leaf iron concentration by 88% compared to control and increased leaf zinc concentration 110% compared to control treatment. The researchers believe that sulfur oxidation and sulfuric acid production in the soil reduce soil reactions and increase the absorption capacity of phosphorus and microelements. The effect of sulfur on the concentration of leaf phosphorus was significant. The phosphorus concentration was increased significantly with sulfur application into the soil, so that 1,000 kg.ha-1 of sulfur increased the concentration of leaf phosphorus by 63% compared with the control (0.33%). Research results have shown that phosphorus absorption capacity in soil is highly dependent on soil reaction and reducing soil reaction leads to increased phosphorus absorption capacity. Researchers have reported that sulfur consumption and the production of sulfuric acid, as a result of its oxidation, reduce soil reaction and increase phosphorus availability for plants. The effect of nitrogen, sulfur and the interaction of nitrogen and sulfur on the content of garlic nitrate was significant. Garlic nitrate content decreased with application of sulfur and increased with nitrogen addition. Application of sulfur at 1000 kg.ha-1 significantly reduced garlic nitrate content by 35% compared to control. The application of 100, 200 and 300 kg.ha-1 of nitrogen increased the content of garlic nitrate 97, 210 and 308%, respectively in comparison to control. At all levels of nitrogen addition, sulfur consumption reduced the content of garlic nitrate. Garlic nitrate content decreased with application of sulfur and increased with nitrogen addition. Sulfur application at 1000 mg.kg-1 significantly reduced garlic nitrate content by 35% compared to control (mg.kg-1). Garlic nitrate was increased by the amount of nitrogen consumed. There was a positive correlation between garlic nitrate (Y) as a dependent variable (N) and independent nitrogen (X), which correlated with linear relation with the correlation coefficient of 0.99. Researchers have argued that excessive consumption of nitrogen fertilizers is the main factor causing the accumulation of nitrate in a number of vegetables and other plants such as garlic. Conclusion: Based on the results of the experiment, it was concluded that nitrogen and sulfur increase the yield of garlic. Meanwhile, sulfur reduces nitrate accumulation in garlic. Sulfur consumption reduces soil pH and increases the absorption availability of micronutrients and phosphorus in the soil and causes more absorption of these elements by the plant.
Research Article
Maryam Haghighi; Atena Sheibanirad
Abstract
Introduction: Plants are constantly faced with abiotic and biotic stresses during their whole life. Abiotic stresses are various adverse environmental factors, including drought, high salinity, heavy metals, cold or heat shock, and ozone. Resulting in dehydration and osmotic stress, drought has caused ...
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Introduction: Plants are constantly faced with abiotic and biotic stresses during their whole life. Abiotic stresses are various adverse environmental factors, including drought, high salinity, heavy metals, cold or heat shock, and ozone. Resulting in dehydration and osmotic stress, drought has caused a dramatic reduction in crop production globally. Grafting can reduce the content of Malondialdehyde (MDA); prevent the accumulation of reactive oxygen species (ROS); increase activities of antioxidant enzymes; and maintain fresh and dry weights, grain yield, and relative water content in a variety of plants in response to drought stress. On the other hand, a range of abiotic and biotic elicitors can confer tolerance to drought stress in plants. Grafting of herbaceous fruit vegetables can reduce detrimental effects of biotic and abiotic challenges and cultural practices. Grafting can increase yield of cucurbits, initiate shoot growth, aid in resistance against nematodes and viruses, withstand high and low temperatures, improve nutrient and water absorption, resist against high concentration of salt, drought and waterlogging stresses. Grafting elite commercial cultivars onto selected vigorous rootstocks is a special method of adapting plants to counteract environmental stresses. Grafting is currently regarded as a rapid alternative tool to the relatively slow breeding methodology for increasing the environmental-stress tolerance of fruiting vegetables. Potential approach to reduce losses in production and improve water use efficiency under drought conditions in high-yielding genotypes would be to graft these varieties onto proper rootstocks capable of reducing the effect of water stress on the shoot and to increase tolerance to abiotic stresses. Cucumber (Cucumis sativus L.) is one of the main greenhouse vegetable crops widely grown in Saudi Arabia. The total greenhouse area for cucumber production in 2013 was 2605 hectares produced 236,087 tons. Major factor influencing growth and yield of cucumber is water quantity. The effects of different rootstocks on plant growth, yield, fruit quality and water consumption in cucumber was studied. The highest yield was obtained from 9075 (19.02 kg m2), which was 24.5 and 23.5% higher than in the non-grafted and self-grafted treatments, respectively. The plant height also increased with the use of rootstocks. The increase in the dry weights of the leaves and fruits depended on rootstocks. They concluded that grafting improved plant growth and yield depending on the rootstock genotype. Grafting has the potential to be as a strategy to increase the tolerance of plants to promote water use efficiency (WUE). The present study was aimed to evaluate the grafting biochemical and physiological effects on inducing drought stress resistance in cucumber. Materials and Methods: This experiment was conducted in complete randomized design with three replications and treatments are included grafted and ungrafted plants, and water potential level 0 (control), -0.4 and -0.8 MP. The Isfahan endemic cucumber specious as a scion with the hole method grafted on Ferro rootstock. The physiological and growth traits were measured. Photosynthesis (stomata conductance, photosynthesis, water use efficiency), growth (root and stem growth), and antioxidants (SOD, POD, protein) parameters, and transpiration were measured. Results and Discussion: Result indicated that grafting with increasing root nutrient absorption and its development drought stress resistance improved. Although, grafting reduced potassium content. Grafting and the interaction of rootstock ×scion impressed many morphological and physiological characteristics. Under stress condition, some features improved plant water relationship, growth and development. Gas exchange indices like photosynthesis, transpiration and stomatal conductance were lower in grafted plant compare to ungrafted plants. Proline content was significantly increased in grafted treatments compare to ungrafted ones. Higher potassium under -0.8 MP in grafted plants showed the maintenance osmotic stability and potassium hemostasis were the draught stress mechanism in resistant rootstocks. Conclusion: Finally, grafting as an efficient method to increase cucumber yield and improve drought resistance recommend. These results suggest that the use of drought tolerant Cucurbita rootstock can improve cucumber photosynthetic capacity under drought stress and consequently crop performance. The results revealed that grafted plants had better vegetative growth than ungrafted (control) ones. Furthermore, photosynthetic parameter, antioxidant activity and fresh and dry weight of stem and leaves were improved, but grafting had no significant effect on fruit quality and yield. In conclusion it is recommended that grafting procedure in some crops include cucumber should be done only after assuring the benefits and risks of grafted seedlings.
Research Article
Bijan Soltanian; Parviz Rezvani Moghaddam; Javad Asili
Abstract
Introduction: Nowadays the demand for medicinal plants is increasing in the pharmaceutical industries. Echinacea spp. is an herbaceous, perennial plant containing valuable substances which belong to different chemical groups, most notably phenolic compounds. Echinacea is the most well-known and most ...
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Introduction: Nowadays the demand for medicinal plants is increasing in the pharmaceutical industries. Echinacea spp. is an herbaceous, perennial plant containing valuable substances which belong to different chemical groups, most notably phenolic compounds. Echinacea is the most well-known and most important treatment for the immune system and protects against cough, cold and fever. Drought stress can be a major factor in increasing the content of secondary metabolites in many medicinal plants. Organic fertilizers are known to be one of the fertility factors for soil and plant nutrition due to the impacts on the physical, chemical and biological properties of soil. The purpose of this study was to investigate the response of yield and phenolic compounds as the most important group of active compounds in Echinacea in response to different levels of water stress, chemical and organic fertilizer management and their interactions. Materials and Methods: This experiment was carried out during 2016 and 2017 years at the experimental Field of Ferdowsi University of Mashhad, located at 10 km East of Mashhad. The split plot based on factorial design was implemented in 3 Replications. The studied factors in this experiment in the main plot were water stress at three levels, including1- Non-Water stress (6000 m3.ha-1), 2- Moderate Water Stress (4500 m3.ha-1), 3- Severe Water stress (3000 m3.ha-1).In sub plots, fertilization treatments applied in eight levels, including, 1- NPK fertilizer (500 kg.ha-1) ; 2-Humic acid (20 L.ha-1); 3-Vermicompost (6000 kg.ha-1); 4-Humic acid+NPK (20 L.ha-1+500 kg.ha-1); 5. Vermicompost+NPK (3000 kg.ha-1+250 kg.ha-1); 6-vermicompost+humic acid (3000 kg.ha-1+20 L.ha-1); 7. Vermicompost+Humic acid+NPK (3000 kg.ha-1+20 L.ha-1+250 kg.ha-1) and 8.control. The amount of irrigation needed at each turn was calculated by NETWAT software. In combined treatments, half of the NPK fertilizer which used in the pure treatment was replaced with the equivalent amount of vermicompost. Constant amount of liquid humic acid was applied at the same time with vermicompost and NPK in rosette leave developing and before stem-elongation phase. The total amount of phenolic compounds in the sample was evaluated by the Folin-Ciocalteu method. Data were analyzed with MSTAT-C statistic software and means compared by Duncan Multiple Range Test. Results and Discussion: The most amounts of stem dry matter, flower dry matter and biomass were observed at vermicompost and non-stress treatment and the least amount of them was obtained from control and severe water stress condition. The highest amounts of leaf and root dry weight were obtained under vermicompost+humic acid and moderate water stress treatments and the least amount of leaf dry weight was observed at control and severe water stress treatments. At the same time with the increase of water stress, the impact of organic fertilizers on leaf dry weight decreased, however the application of organic fertilizers increased the leaf dry weight even under severe stress conditions. Maximum seed yield was observed under vermicompost+humic acid+NPK and NPK treatments with severe water stress condition. With increase in the stress level, root to shoot ratio was increased and the maximum amount of that was obtained in control treatment under severe water stress condition and the minimum amount of that was obtained at vermicompost and non-stress treatment. The application of vermicompost and humic acid increased root to shoot ratio in severe stress conditions and it were effective in developing root systems in these conditions. Maximum amounts of phenolic compounds were observed under humic acid+vermicompost treatment with severe stress condition and minimum of these compounds were obtained under humic acid treatment at no-stress. Conclusion: The response of aerial parts of plant was associated with a decrease in irrigation levels, however this trend was reversed in underground sections. Thus, the maximum amount of root dry weight, root to shoot ratio and root phenolic compounds were observed in severe stress treatment. The highest amount of Phenolic compounds of the root, the ultimate goal of this plant, were observed under humic acid+vermicompost combination treatments. Therefore the production of this plant in terms of supplying 50% of the required moisture content (is equivalent to 300 mm of irrigation during the one-year growth period) and the use of fertilizer treatments containing humic acid and vermicompost compounds is recommended.
Research Article
Heshmat Omidi; Fatemeh Pirjalili; Khadijeh Ahmadi
Abstract
Introduction: Water deficit is one of the major abiotic stresses, which adversely affects crop growth and yield. Plants use two different strategies, including drought avoidance and drought tolerance to grow under drought stress. Drought avoidance species are able to have a normal growth, which is due ...
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Introduction: Water deficit is one of the major abiotic stresses, which adversely affects crop growth and yield. Plants use two different strategies, including drought avoidance and drought tolerance to grow under drought stress. Drought avoidance species are able to have a normal growth, which is due to: 1) efficient and fast metabolism, 2) high uptake of water and nutrients, and 3) little production of secondary metabolites under deficient water conditions. While drought tolerance species maintain their regular growth, under drought stress, by: 1) adjustment of osmotic potential, 2) changes in cell wall properties, and 3) production of antioxidants and secondary metabolites, these species under prolong drought, and irrespective of plant type, plant produces higher rate of secondary metabolites, as a non-enzymatic mechanism. Such products are able to maintain plant activities, under oxidative stress, and in the presence of high rate of reactive oxygen species. Medicinal plants, including Balangu (Lallemantia royleana Benth.), are cultivated across different parts of the world including Iran for food and biodiesel purposes. Investigating the effects of drought stress on the production of secondary compounds by medicinal plants is an important issue. According to the previous studies drought stress increases the production of secondary compounds affecting the quality of medicinal plants. This must be considered when developing tolerant medicinal plants under stress, especially if the quality of medicinal plants is of higher importance than their quantity. The tolerance of medicinal plants is different under stress. Due to the importance of drought and its effects on the growth and the quality of medicinal plants, in this research the effects of stress intensity and plant species on the growth and physiology (including the medicinal contents) of Balangu plants were investigated. To our knowledge, there are not much data on such effects. The objectives of this study were to investigate the effects of drought stress on: 1) Balangu growth and yield, and 2) Balangu physiology including the activities of morphological traits, yield components and oil yield and the production of antioxidant enzyme affecting plant medicinal content. Materials and Methods: This study was conducted to investigate grain yield, yield components, and superoxide dismutase enzyme in three populations of Balangu (Lallemantia royleana Benth.) under drought stress. This study was conducted as a split plot experiment based on randomized complete block design with three replications at the experimental field of Shahed University during 2013-2014 growing season. The main factor consisted of four levels of drought stress (soil moisture content of -0.5, -3.5, -6.5 and -9 atm) and three Balangu Shirazi populations (Mashhad, Kerman and Taleghan) as sub-factors were considered. The main factor included drought stress levels at four levels (soil moisture content of -0.5, -3.5, -6.5 and -9 atm) and three Balangu Shirazi populations (Mashhad, Kerman and Taleghan) were considered as sub-plots. Measured traits were included root length, plant height, fresh and dry weight per plant, grain yield, grain yield components, mucilage percent and yield. In order to study the morphological traits, seven plants of each plot were selected with consideration of marginal impacts. About four square meters of each plot was harvested at maturity for determination of yield and its components.. The analysis of variance was does through SAS 9.12 statistical program and the means were compared by Duncan's multiple range test in 5% level. Results and Discussion: A set of yield and biochemical properties of three different species of Balangu which were affected by drought levels were determined. According to the analysis of variance the yield and biochemical properties of Balangu were significantly affected by drought, and there were significant differences between three species. The results showed that drought stress had a significant effect on growth components, yield components, grain yield, and oil yield and superoxide dismutase enzyme. With decrease of soil water content, plant height traits (24.73 cm), the number of branches (5.44), fresh (17.36 g) and dry (3.80 g) weight of plant, 1000-grain weight (1.51 g), harvest index (6.41 %), grain yield (157 kg.ha-1) and oil yield (37.77 kg.ha-1) decreased. Root length and superoxide dismutase content increased by 24.02 and 66.63% under severe stress compared to no stress condition, respectively. The highest grain and oil yield was obtained in Mashhad population under drought stress. In relatively severe stress conditions, the grain and oil yield of Taleghan population increased with the mean of 315.75 and 86.5 kg.ha-1, respectively. Under drought stress levels, the lowest reduction was observed in some growth characteristics and grain yield of Kerman population. Conclusion: Overall, the results of this study demonstrated that drought stress at flowering stage increased root length and superoxide dismutase enzyme of the studied populations. Furthermore morphological traits, grain yield components, harvest index, relative water content, grain yield and seed oil of Balangu populations were decreased. The highest seed and oil yield gained under moderate stress which belongs to Taleghan population and Mashhad population revealed the highest seed and oil yield under mild stress. Therefore, given the high stresses, introducing high-yielding populations under relatively severe stresses can lead to water use efficiency and irrigation management. Finally, the production of Taleghan population under relatively severe conditions such as arid and semi-arid cropping systems is recommended.
Research Article
Norollah Moallemi; Esmaeil Khaleghi; Zeinab Jafari zadeh
Abstract
Introduction: Plant establishment is difficult in some arid and semi-arid regions of Iran because of lacking rainfall and inadequate distribution and extreme heat. Previous studies stated that plant water parameters and growth characteristics such as plant height, fresh and dry weight of root, stem and ...
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Introduction: Plant establishment is difficult in some arid and semi-arid regions of Iran because of lacking rainfall and inadequate distribution and extreme heat. Previous studies stated that plant water parameters and growth characteristics such as plant height, fresh and dry weight of root, stem and leaf, which is known as the first reaction of plants, were decreased under drought stress. Therefor it is necessary to use practices with objectives to decease the effects of drought stress on plants and increasing water use efficiency. Several studies showed that various morphological and physiological characteristics in plants were influenced by ascorbic acid. In fact, ascorbic acid increased plant resistance to drought stress. The purpose of this research was to investigate the effect of ascorbic acid application on growth traits of ‘Baghmalek’ olive under 100%, 66% and 33% ETcrop < /sub> by analyzing growth traits and relative water content, stem water potential and stomata resistance. Material and Methods: This research was carried out in order to assess the effects of three levels of water deficit (100, 66 and 33 percent of evapotranspiration (ETcrop < /sub>)) and four concentrations of ascorbic acid (0, 250, 500 and 750 mg l-1) on some growth and physiological parameters of young olive plants cv. ‘Baghmalek’as a factorial experiment based on a randomized complete block design with three replications. Fresh and dry root, stem and leaf weight, leaf number, leaf area, stem diameter, relative water content, stem water potential and stomata resistance were measured in this research. Two years old olive trees (Olea europaea cv. ‘Baghmelak’) were used. Seventy two plants were grown in 10 L pots, containing a mixture of field soil: sand: manure (1:1:1). Plants were sprayed with four concentrations of ascorbic acid and irrigated every 10 days, based on the amount of evapotranspiration of plant (ETcrop < /sub>). Parameters such as relative water content, stem water potential and stomata resistance were measured at last week of the experiment and the other parameters were measured every week. Data analysis were performed using MSTATC software and means comparison were carried out by Duncan's multiple range test (DMRT) at 5% and 1% of probability levels. Results and Discussion: The results indicated the growth quality was better in plants treated with 250 mg l-1 ascorbic acid under water stress. Fresh and dry weight of root, stem and leaf growth, stem diameter, leaf number, leaf area were higher in plants treated with 250 mgl-1 ascorbic acid than untreated plants. Interaction between water deficit stress ×ascorbic acid revealed information in plant characters such as fresh and dry weight, stem diameter and leaf area simply declined as sources of water (from 100 to 66 and 33 percent) become limited, in particular in the trees which not receiving ascorbic acid treatments. However, application of 250 and 500 mg l-1 ascorbic acid enhanced the amount of relative content of leaf and water potential of stem in trees under water deficit stress. While stomata resistance was decreased in trees receiving ascorbic acid treatments. Some researcher declared that limitation of photosynthesis could be one of the most important factors for decreasing growth under water deficit stress. In addition, relative water content, cell turgor potential, reduced cell division, cell enlargement and growth plant could be affected by water deficit stress. Also the results indicated that leaf area (5952 cm), leaf number (151.7), stem diameter (6.49 mm), stem length (63.33 cm), root dry weight (18.16 g) and leaf fresh weight (9.35 g) were obtained in irrigated plants with 33% ETcrop < /sub> and untreated with ascorbic acid. Our results showed leaf number (158.7), stem length (74 cm), root fresh weight (78.08 g), stem fresh and dry weight (46.45 and 28.43 g, respectively) and leaf fresh and dry weight (13.35 and 8.45 g, respectively) were highest in irrigated plants with 100% ETcrop < /sub> and treated with 250 mg l-1 ascorbic acid. Conclusion: Water deficit stress could affect directly on relative water content, cell turgor potential and reduce cell division, cell enlargement, plants photosynthesis and plant growth. The use of ascorbic acid could effect on plants resistance to drought. In addition, various morphological and physiological traits could be influence by ascorbic acid. The results of this research indicated that 250 mg l-1 ascorbic acid concentration had more effects on water deficit and it seems ascorbic acid can be used to reducing the negative effects of drought in some regions that rainfall shortage and drought is important problems.
Research Article
َAysan Samadi; Akbar Hassani; Majid Gholamhoseini
Abstract
Introduction: Plant growth promoting bacteria are beneficial microorganisms that produce plant resistance to a variety of biological and non-biological stresses, including drought, extreme temperatures, salinity, toxic metals, etc, and increase plant productivity and yield. The use of these microorganisms ...
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Introduction: Plant growth promoting bacteria are beneficial microorganisms that produce plant resistance to a variety of biological and non-biological stresses, including drought, extreme temperatures, salinity, toxic metals, etc, and increase plant productivity and yield. The use of these microorganisms as biological agents in increasing soil fertility and improving agricultural productivity has been studied by many researchers, so a proper understanding of their effect on drought resistance can be effective in water resources management. Useful in field and reducing environmental effects of using chemical fertilizers. The purpose of this study was to investigate the effect of some bio-fertilizers on growth and some physiological and biochemical characteristics of red radish and in comparison with potassium sulfate application under drought stress.
Material and Methods: In other to investigate the effect of application of bio-fertilizers containing potassium-soluble bacteria (Pseudomonas koreensis and Pseudomonas vancouverensis), phosphorus-solubilizing bacteria (Pseudomonas putida) and nitrogen-fixing bacteria (Pantoea agglomerans) on plant growth and function, this experiment was done with 10 treatments and three replications in the form of completely randomized design in greenhouse. Finally the statistical population consisted of 30 pots of 10 treatments and three replications for red radish. Drought stress was applied in such a way that the apparent symptoms of stress were seen in the plants and the amount of water used was the same for all plants. The experiment was carried out in greenhouses and nylon pots with a capacity of 6.5 kg were used. The soil was prepared using a calcareous soil of Zanjan University research field. Its absorption was less than critical. Organic matter content was 0.4% and lime equivalent was 14.1% pH of soil 7.57 and EC of abstract soil paste was 2.21. Pots were treated with municipal water for 25 days after planting. EC values of water was 400 µS / cm that irrigated the plants every three days. The desired bio-fertilizers were added to the pots with irrigation water. After 25 days, 15 pots of treatments 4 to 6 were subjected to drought stress. 40 days after planting before drying of the plants, weight, moisture content of plant tissue, leaf proline content, total free amino acid, and total soluble sugars in leaf extract were measured. Analysis of variance was performed using SAS software and LSD test at the 5% level was used to compare the means.
Results and Discussion: Results of analysis of variance showed that the effect of different treatments on aerial fresh weight was significant at 1% level. Fertilizer treatments under stress and non-stress conditions significantly increased aerial fresh weight. Among non-stress treatments, the highest fresh weight was obtained from treatment 2 (10.03 g / pot) and the lowest was in control treatment (6.55 g / pot). Among the drought stress treatments with application of different fertilizers used, treatment 8 (9.19 g / pot) had the highest and treatment 6 (7.04 g / pot) had the lowest fresh weight. Application of potassium sulfate fertilizer increased the fresh weight of aerial part both under stress and non-stress condition. Potassium soluble bio-fertilizer alone and in combination with other bio-fertilizers increased radish aerial fresh weight, which was not significantly different from potassium sulfate fertilizer. In radish, drought stress affected the tuber fresh weight more. The radish plant uses the water of the tuber reserve in drought stress so that the leaves are less susceptible to stress. In non-stress conditions, application of potassium sulfate fertilizer and bio-fertilizers in radish increased yield. Potassium sulfate effect was greater. In stress conditions, the effect of bio-fertilizers was more than potassium sulfate in stress condition. The effect of potassium soluble bio-fertilizer application was almost identical with the combined application of different biofertilizers. Drought stress increased the concentration of proline, amino acids and soluble sugars in leaves and tubers of radish. Increasing concentration of these compounds indicated that plants were resistant to drought. Application of potassium sulfate and bio-fertilizers decreased these concentration and the effect of bio-fertilizers was more than that of potassium sulfate. The amount of ion leakage also increased under drought stress but leakage decreased by using potassium sulfate and bio-fertilizers. Drought stress also reduced the starch concentration in leaves and tubers of radish, which is a consequence of drought stress.
Conclusion: In general, application of potassium sulfate and bio-fertilizers moderated the effects of drought stress and in some cases the effect of biofertilizers was greater. Integrated use of bio-fertilizers was not significantly different from the use of potassium soluble bio-fertilizer alone. So, the results of this study showed that the use of bio-fertilizers can be included in the plant nutrition program as a factor in reducing the negative effects of stress on plants.
Research Article
Shahin Jahangirzadeh khiavi; Behrooz Golein
Abstract
Introduction: Citrus fruits are the most common semi-tropical crops in the world. Acid lime (Citrus aurantifolia Swingle) is an important commercial fruit crop, cultivated in the south of Iran. High variation of acid lime fruits is observed in the south of Iran due to crossing within the other citrus ...
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Introduction: Citrus fruits are the most common semi-tropical crops in the world. Acid lime (Citrus aurantifolia Swingle) is an important commercial fruit crop, cultivated in the south of Iran. High variation of acid lime fruits is observed in the south of Iran due to crossing within the other citrus species and frequent bud mutation. Recently, Witch’s Broom Disease of Lime (WBDL) become a major limiting factor for lime production in the South of Iran as well as the main threating factor for lime industry in Iran. Having knowledge about the genetic of this plant is helpful for designing citrus breeding program. Therefore, in this research morphological traits were used to understand the genetic relationships and diversity of this gene pool.
Materials and Methods: Thirty citrus samples, including 23 undefined local and native genotypes and seven known cultivars were collected from four regions in Iran (Darab (54.53E, 28.75N), Manojan (57.49E, 27.40N), Minab (57.07E, 27.14N) and Ramsar (50.64E, 36.92N)). Forty-one (32 qualitative and nine quantitative) traits were investigated using leaves, fruits and seeds. The selection of morphological traits were made based on IPGRI descriptors. The similarity was calculated by simple matching coefficient and dendrogram was designed based on UPGMA algorithms. Principal components analysis was performed.
Results and Discussion: Genetic diversity of 23 lime genotypes and seven commercial cultivars were investigated by using 41 morphological characters. Based on gained data similarity matrix (Jaccard, Dice and Simple maching) were calculated and dendrogram based on UPGMA algorithms were designed. To finding better similarity coefficient, cophenetic test was done, it showed that if used SM coefficient 79 percent of data of similarity matrix was shown in designed cluster based on UPGMA algorithm. According to results, range of similarity was between 0.141 until 0.683. Maximum similarity was observed between two lime cultivars (Persian lime and Mexican lime). Average of similarity was calculated 0.39. In cluster analyses of studied samples at 32 level of similarity samples were divided into four main groups. First group has only one member and it was pomelo, as it is one of the ancestors of citrus fruits, this is quite acceptable. The notable point for second main group that it included all examined samples of Minab. As in this region most of cultivated citrus are lime, there is little gene mixing with other citrus. The third group consist of two cultivars sweet orange and Citon that intended in present investigation. Fourth group which was the biggest created groups that included more than half the samples (56%) was more complex because it consists of samples of limes and lemons that intended in investigation as control and samples of Darab and Manojan. This main group at level of 0.38 divided into three sub-groups, at first, Lisbon lemon was separated from other samples and next Manojan samples created their special sub-group and finally third sub-group which consist of 11 members (samples of Darab, MA6 from Manojan and three commercial cultivars, Persian lime, Mexican lime and Rough lemon). Principle Component Analysis (PCA) showed the first five principal components, which contributed 59.01% of the total variability of investigated samples. Maximum variability was contributed by the first component (22.77%) followed by the second component (12.54%), and the third component (9.85%). A two‐dimensional plot (2D plot) generated from PCA showed three groups. This grouping was roughly in line with the distribution of the samples in the resulting cluster analysis based on SM coefficient and UPGMA algorithm. Principle Component Analysis using 41 descriptors showed that 26 of 41 descriptors were informative and contributes significantly to the variation present in the germplasm.
Conclusion: This study described and estimated the extent of phenotypic variation present among the samples of limes from Iran germplasm. Morphological analyses among 23 genotypes and seven commercial cultivars from four regions of Iran were successfully used to calculate genetic diversity and genetic relationships. According to our results, it was confirmed that morphological analyses in limes and other Citrus species were exploit to determine genetic diversity and relationship, successfully. Characterization by using morphological descriptors based on 41 characters, revealed significant diversity in traits of leaf, fruit and seed. This investigation display the use of morphological characters to study genetic diversity of Iranian lime genotypes from four different regions that their relationships were somewhat clarified. The results of this study also opened a door to tackle the long standing problem of citrus classification and identification in Iran. But, we suggest that this type of study needs to be continued due to Iran has a very large and numerous citrus germplasm. In south and central regions of Iran, it is being propagated by seed which gives researchers a chance to find new genotypes that need to be classified, investigated and introduced as a new cultivar.
Research Article
Mahboobeh Naseri; Hossein Arouiee; Maryam Mohammadi
Abstract
Introduction: Spinacia olerace is the most important leaf vegetable of the Chenopodiacea family, which has a special place in human nutrition because of its variety of minerals and vitamins. Cultivation of this plant in Iran is several thousand years old and accordingly Iran is considered as the main ...
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Introduction: Spinacia olerace is the most important leaf vegetable of the Chenopodiacea family, which has a special place in human nutrition because of its variety of minerals and vitamins. Cultivation of this plant in Iran is several thousand years old and accordingly Iran is considered as the main place and a source of spinach in the world. Growth of plants is affected by genetics, environmental conditions, growing season, nutrients, and soil, harvesting method, temperature, intensity and quality of light. Among these factors, soil nutrients have a significant influence on plant growth and yield. Nowadays, the consumption of organic matter as fertilizer due to its high cost and limited availability is not sufficient and the major nutritional needs of plants are met by chemical fertilizers, which can lead to environmental problems and, over time, reduced yields. In this connection humic acid is a naturally occurring organic compound and contains 2% to 5% organic matter. Humic acid can be used to seedling nutrition and improve its quality and quantity. Given the recent use of organic acids such as humic acid to improve crops and horticulture, but little research has been done on transplant birth, this experiment was conducted to investigate the application of different levels of humic acid in irrigation water at the time of irrigation. Different effects and their effects on growth indices and spinach production were investigated.
Material and Methods: The present experiment was conducted to investigate the application of different concentrations of humic acid at different times and its effects on quantitative and qualitative indices of spinach in a factorial completely randomized design with three replications in research greenhouse at Torbat Heydariyeh University. Treatments consisted of three concentrations of humic acid (0, 3 and 6 ml/L) at two application times (one-week and two-week). The mean daily greenhouse temperature at the time of plant growth was 25°C and the mean nighttime temperature was 18°C, the average relative humidity was 60%. After seedlings were planted in the main pots at four-leaf stage, they were irrigated with humic acid (0, 3 and 6 ml/L) at different intervals once a week, twice weekly. The humic fertilizer used belonged to Green Seed Company, containing 24% humic acid and 3% folic acid and 2% potassium. Five weeks after treatment, the traits were measured. Transplant growth indices including number of leaves (by counting the number of shoots per plant), leaf length and width, leaf area, canopy, height, chlorophyll index, chlorophyll a, b, carotenoid and dry weight of each plant were determined.
Results and Discussion: Based on the results of this experiment, the effect of humic acid concentration on morphological and physiological traits of spinach transplant was significant. The highest leaf number (4.6) at 3 ml concentration and the lowest number (3.5) were at zero concentration. These traits were subjected to humic acid titer, but the increase in concentration had no significant effect on these traits. The increased number of leaves and traits mentioned in the early stages of transplant growth is probably due to the rapid expansion of the root system of the plant at high concentrations of humic acid, which in turn leads to increased nutrient uptake, better plant growth and subsequent growth. Leaf number and other traits become leaf dependent. The results showed that the highest chlorophyll a (1.8 ml/g fresh leaf), chlorophyll b (2.5 ml/ml fresh leaf), carotenoids (7.1 ml/ml). Fresh leaf g) and biomass (150 mg) at 3 ml concentration and the lowest at zero concentration. The highest chlorophyll index (74.1 ml/ml fresh leaf g) was also found in the concentration of 6 ml and the lowest was obtained from zero concentration. Humic acid increased spinach transplant biomass by increasing the amount of photosynthetic pigments and leaf area or the same photosynthetic capacity. In most of the traits, the two-week application time was higher than the one-week, so that spinach transplant biomass increased by 110% over the two-week application period. So that spinach transplant biomass was 156 at the two-week application and 74 mg at the one-week application. Based on the results of this experiment, humic acid application can improve the quantitative and qualitative traits of spinach transplant and its production.
Conclusion: Production of vegetable seedlings have an important role in the production and olericulture economy. Specializing in different activities in the vegetable production process will simplify the production process and increase efficiency. This means that the best conditions for seedling growth should be provided during transplanting. Application of humic acid organic fertilizer instead of chemical fertilizer can reduce environmental pollution in line with sustainable agriculture and healthy eating with vegetables to prevent the accumulation of chemicals in the human body to be effective. In this regard, the results of this study showed that using low humic acid as organic fertilizer can improve morphophysiological traits of spinach transplant.
Research Article
Maryam Mohammadiyan; Hamed Kaveh
Abstract
Introduction: there is a growing request for healthy fresh-cut products globally. However, due to the higher respiration of this kind of products and their suseptability to bacterial and fungal pathogenes, they spoil immediately after processing. These microbial activities usually cause a decrease in ...
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Introduction: there is a growing request for healthy fresh-cut products globally. However, due to the higher respiration of this kind of products and their suseptability to bacterial and fungal pathogenes, they spoil immediately after processing. These microbial activities usually cause a decrease in the quality and marketability of the product, including changes in its aroma, taste and appearance. The fresh-cut fruit and vegetable industry is one of the relatively new sectors and while the industry is growing, it is producing new products. Tissue rupture and cell rupture in these products leads to a decrease in their shelf life. On the other hand, these products need serious attention due to increased enzymatic activity, respiratory factors and microbiological considerations.In recent years, there has been growing evidence of consumption of minimally processed fruits and vegetable for the prevention of many chronic diseases. Some chemicals like chlorine, calcium chloride, etc., are used for sanitization purpose in fruit and vegetable industry, but these chemicals form carcinogenic chlorinated compounds, which have adverse human health impacts. Therefore, advanced alternative sanitization techniques, processing methods and improved packaging materials may be implemented for ensuring safety and extending the shelf life of fresh-cut fruit and vegetables. Application of edible coatings showed acceptable results on microbial load reduction and better preservation of processed products from the fruit to vegetables. Apple with proper nutritional value as a healthy snack have been considered in the diet of schools, public consumption and families. Finding a safe treatment to increase shelf life of freshly cut apples without harmful effets on environment and consumer is the main goal to this reaserch. Materials and Methods: In this study, the effect of fennel essential oil (Foeniculum vulgare L.) with Aloe vera gel (in 3 levels of zero, 10 and 25 ml / l) and two magnetic field intensity (0 and 60 ml Tesla) in 3 replications during 7 days and in two storage temperatures (8 and 25 ° C) were observed. All treatments except the control were coated with Aloe vera gel. It was done in factorial format with a completely randomized design. In which traits such as color quality, SSC, pH, physiological weight loss, and browning rate were studied. Discussion and Conclusion: The results showed that the presence of the magnetic field in all samples treated with Aloe vera gel reduced the degradation, decrease oxidation and increase preservation of the appearance indices of apple slices. The presence of Aloe vera gel in all cases reduced water content reduction and weight loss. In the samples treated with different levels of fennel essential oil, fungal and bacterial growth was prevented, but in terms of appearance indices, it had a great decrease in quality and increased browning. No mold and fungal growth was observed in the samples at 8 and 25 ° C. Apparently, apples treated with 25 ml of essential oil lost their marketability. The use of Aloe vera treatment alone and without essential oil with a 60 ml Tesla magnetic field was found to be the best treatment. In general according to the results of this study, the application of fennel essential oil, which has antioxidant properties in lower concentrations, is useful to prevent the prevent fungal and bacterial growth, but is not suitable in terms of maintaining the appearance and reducing tissue destruction and causes faster and higher oxidation. Apple slices treated with high essential oil concentration became completely brown and lost their marketability even more than the control samples. Finally, it could be said that Aloe vera gel treatments in which a magnetic field was applied, in addition to water retention, had the best appearance and less oxidation. However, the use of Aloe vera gel and magnetic field to maintain the appearance is very useful and can be used in this industry.
Research Article
Ali Akbar Shokouhian; Farzad Letafatti; Bahram Fathi Achachelooee; Ali Asghari; Robab Olfatti
Abstract
Introduction: Grape is a non-climacteric fruit. Its ripening is associated with increased sugars, decreased acidity and development of color and flavor. Edible films and coatings could be used as a selective protection method to extend storage life of fruits. Edible coatings reduce the absorption amount ...
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Introduction: Grape is a non-climacteric fruit. Its ripening is associated with increased sugars, decreased acidity and development of color and flavor. Edible films and coatings could be used as a selective protection method to extend storage life of fruits. Edible coatings reduce the absorption amount of brine, osmotic solution and frying oil into foods, improve mechanical properties, facilitate displacement and storage strengthen food structure, reduce spoilage and increase its shelf-life. The coatings provide a protective layer for fresh fruits and act as like as modified atmosphere packaging, change the composition of internal gases, and increase the storage-life of fruits by reducing respiration rate. Zein, is an important protein in corn seed and consists about 45 - 50% of the corn proteins. This protein contains a group of Prolamines found in the corn endosperm. Zein has unique properties for preparing edible films and coatings in comparison to other plant proteins due to its high percentage of nonpolar amino acids. Gluten is an insoluble in water protein of wheat that its disulfide bonds play an important role in the establishment of gluten films. Prepared films from wheat gluten are pure and transparent, but commercial gluten produces an opaque film due to gelatinization of its existing starch. Wheat gluten-based films have satisfactory mechanical resistance and very low oxygen permeability. Gluten can encapsulate flavors, colors, or medicines, providing slow-release materials. Bacteria, fungi, or other pest- or weed-control agents can be encapsulated in gluten granules that are then coated with oil to slow drying and maintain vitality. Materials and Methods: This study was carried out to investigate the effects of gluten and zein coatings on postharvest quality of grape cultivars in a factorial arrangement based on randomized completely design with application of corn’s Zein coating treatments at four levels (control, 2, 4 and 6% w/w) and also wheat gluten at four levels (control, 2, 4 and 6% w/w) were performed in the grape cultivars (Meshkin cultivar). Grape fruits were harvested from the gardens of Meshkin city and moved to the laboratory in the University of Mohaghegh Ardabili. Then, after applying the treatments, fruits were kept at 0° C and humidity of 90-95% in cold storage. In this study, pH, total soluble solids, total acidity, starch, anthocyanin, firmness, taste, fruit storage-life, TSS/TA, weight loss, appearance and vitamin C content of fruits were measured in 30 days after applying the treatments. Results and Discussion: The results of analysis of variance showed that using of zein as grape coating had significant effect on total soluble solids, vitamin C, taste and weight loss (p < 0.01) and on the TSS /TA attribute (p < 0.05).The use ofgluten also had a significant effect on total soluble solids, anthocyanin, weight loss and vitamin C (p < 0.01) and also on the fruit starch (p < 0.05). Interaction effect of gluten and zein treatments were significant on total soluble solids, vitamin C (p < 0.01) and fruit weight loss (p < 0.05). Based on the obtained results, the highest starch content, anthocyanin, maturity index and taste were achieved by using of gluten at 4 and 6% and the lowest amount of these substances was related to control treatment. A higher amount of anthocyanin (2.45 mg / 100 g) was retained in 6% gluten treatment, Moreover, in the fruit ripening index, the best result (41) was obtained from 6% zein treatment. The taste of the fruit was also more attractive in the 6% zein treatment without gluten consumption with a score of 8.5. Also, the best results in preservation of vitamin C (17.9), soluble solids (24 brix), fruit appearance (9.5 points) and the least weight loss of fruit (6.5%) were obtained from the combination of gluten and 6% zein treatment. Comparison of the means showed that vitamin C and soluble solids were better preserved by combined using of 4 and 6% gluten with 6 and 4% zein in storage period. These results showed that vitamin C and soluble solids had the lowest stability under control conditions. Also, the control treatment had the highest weight loss and the lowest score in the fruit preservation index. In overall, the best results in most of the studied parameters were obtained from the treatment combination of 6% gluten and zein. Conclusion: Based on the obtained results, gluten and zein coatings in comparison to control treatment at levels of 6%, had significant positive effects on post-harvest quality and storage of grapes.
Research Article
Reza Najafi; Taher Barzegar; Farhang Razavi; Zahra Ghahremani
Abstract
Introduction: Eggplant (Solanum melongena L.) is an important non-climacteric fruit grown in tropical and subtropical regions. The total production in Iran and world for eggplants in 2018 were estimated 54077210 and 666838 tons, respectively, and Iran ranked fifth in the production of this product. The ...
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Introduction: Eggplant (Solanum melongena L.) is an important non-climacteric fruit grown in tropical and subtropical regions. The total production in Iran and world for eggplants in 2018 were estimated 54077210 and 666838 tons, respectively, and Iran ranked fifth in the production of this product. The health-promoting attributes of eggplant are derived from the phytochemicals with good source of antioxidants (anthocyanin and phenolic acids), dietary fiber and vitamins. Fruit deterioration during long term storage is associated with appearance quality reduction, calyx discoloration, softening and pulp browning caused by the oxidation of phenolic compounds. Hydrogen Sulfide (H2S) is a flammable and colorless gas, that similar to carbon monoxide and nitric oxide, is known as third leading signaling molecule. It has been reported that H2S play an imperative role in the postharvest physiology and chilling injury of various fruits and vegetables. In recent years, exogenous phenylalanine (PA) application has been employed as a beneficial procedure for enhancing quality in fruits and vegetables by promoting higher phenols and flavonoids accumulation arising from higher PAL enzyme activity and proline accumulation exhibiting higher ROS scavenging capacity. Thus, the aim of this study was to investigate the postharvest application of H2S and PA on quality and postharvest storage of eggplant fruit during storage at 7 °C for 21 days. Material and Methods: Eggplant fruits (Solanum melongena cv. Hadrian) were harvested at commercially maturity stage in Jun 2019 from a greenhouse in Hashtgerd city, Iran. Fruit selected for uniform size, shape, and color, and immediately transported to the laboratory. They were divided into seven parts for the following treatments: control (0), hydrogen Sulfide (H2S) at 0.1, 0.2 or 0.3 mM and phenylalanine (PA) at 2.5, 5 or 7.5 mM. Each treatment was done in three replicates, consists of 24 fruits from each replicate, and then randomly divided into four groups include six fruits. One group was analyzed 24 hrs. after harvesting and another groups stored at 7 ± 1 °C and 85% RH for 21 days. At 7-day intervals, one group was taken at random and transferred for one day at 20 °C (shelf-life), and subjected to physicochemical analysis. For H2S fumigation, fruit was placed at the bottom of a sealed 15 L container with different aqueous sodium hydrosulfide (NaHS) solution concentrations for 10 min, and for PA treatments, the fruits were immersed in 10 L of fresh phenylalanine solution for 10 min and in distilled water as a control. The fruits were allowed to completely dry at room temperature before storage. Results and Discussion: The results showed that fruits treated by PA and H2S exhibited higher fruit firmness, chlorophyll, anthocyanin, total soluble solids (TSS), vitamin C, pH and titratable acidity (TA) accompanied by lower weight loss and chilling indices during storage at 7 ºC for 21 days. In control eggplant fruits, fruit firmness (24.2%), chlorophyll (45.8%), vitamin C (34.1 %), anthocyanin content (66.2 %) and TA (44.8) decreased, and weight loss (7.5 %), TSS (8.2%) and chilling indices (4.5 %) increased during 21 storage time. The maximum fruit firmness (1.37 and 1.34 kg cm-2), anthocyanin content (5.02 and 4.2 mg L-1) and TA (18.67 and 1.37 %), and the lowest weight loss (3.67 and 3.7 %) and chilling index (1.6 and 1.3 %) was found in fruits treated with H2S at 3 mM and PA at 7.5 mM during storage at 7 °C for 21 days, respectively. It has been reported that texture correlates with firmness and higher firmness is a characteristic indicator of good texture during postharvest storage of fresh products. Soluble solid contents, titratable acidity (TA) and sugars have been known as important attributes contributing in overall sensory quality of fruits and vegetables. Development of the chilling injury disorder significantly reduces quality of fruits and vegetables due to diminished consumer’s acceptance. So, start of chilling injury symptoms eventually becomes economically critical postharvest constraint that defines the storage life potential of the products. Decline chilling injury in responses to H2S and PA treatments may resulted from higher ROS scavenging enzymes SOD, CAT, APX and POD activity and proline, phenols and flavonoids accumulation giving rise to conferring chilling tolerance. Conclusion: According to results, PA at 7.5 mM and H2S at 3 mM had the highest positive effect on maintain firmness and fruit quality and reducing weight loss and chilling, therefor postharvest treatment of PA and H2S can be proposed to improve fruit quality and postharvest life during storage period.
