Medicinal Plants
Behrooz Rahimkhani; mahboobeh naseri; ahmad ahmadian; Masoud alipanah
Abstract
Introduction:
From the past, medicinal plants have been used as one of the most important resources for medicinal purposes. Even now, the use of medicinal plants is expanding in many developed. Salinity stress is one of the most important influencing factors in reducing plant growth. Salinity stress ...
Read More
Introduction:
From the past, medicinal plants have been used as one of the most important resources for medicinal purposes. Even now, the use of medicinal plants is expanding in many developed. Salinity stress is one of the most important influencing factors in reducing plant growth. Salinity stress limits plant growth by reducing metabolic and physiological activities in the plant. One of the consequences of salinity stress in the plant is the production of abscisic acid in the plant. One of the methods that have been tested in recent years to reduce the effects of salinity stress in plants is the use of seaweed and its extract. According to the studies conducted in some plants, seaweed extract can cause the growth and expansion of the roots and help to increase the absorption of water and minerals through the roots. Also, based on the research conducted on some plants, the use of seaweed increases the amount of chlorophyll in the plant and accelerates the time of flowering and fruit formation in the plant. Echium amoenum is a perennial plant belonging to the family Borage is a valuable plant in terms of its medicinal properties is considered. in general environmental factors have a significant effect on flower production in these plants. Therefore, for the successful cultivation of medicinal plants, including in general environmental factors have a significant effect on flower production in these plants. Therefore, for the successful cultivation of medicinal plants, including Echium amoenum, providing optimal environmental conditions is a priority, providing optimal environmental conditions is a priority.
Ascophyllum nodosum seaweed extract contains significant amounts of high-use mineral elements such as nitrogen, potassium, calcium, magnesium, and low-use mineral elements such as iron, copper, and manganese. Therefore, according to the current results, in this study, the effect of foliar spraying of algae extract was investigated. The morphological characteristics of Echium amoenum seedling under salt stress were investigated
Materials and Methods
In order to investigate the effects of foliar spraying of seaweed extract on borage flower seedlings under salinity stress conditions, a factorial experiment was conducted with two factors of seaweed and salinity stress with sodium chloride salt, in the form of a completely randomized design in the greenhouse. The seeds were purchased from Pakan Seed Company of Isfahan and soaked in normal water for 24 hours, and then they were transferred into small pots containing three parts of peat moss and one part of perlite. One week after transferring the seedlings to the main pots, foliar spraying with seaweed extract was done. Foliar-spraying was repeated once every two weeks and in total the seedlings were sprayed three times with seaweed extract. In this experiment, a concentration of 1500 ppm of seaweed extract and three levels of salinity (EC=1.6, 4, 8) were used.
The seaweed extract used in this experiment belonged to Akadin Company. The type of seaweed from which the extract was prepared was Ascophyllum nodosum and it is a type of brown algae. One week after the first foliar application of seaweed extracts, the application of salinity stress began. In order to prevent shock in plants, salinity treatment was done gradually and in three stages. In order to prevent salt accumulation, washing with ordinary water was done once every two weeks.
Results and Discussion
The results showed that the use of seaweed extract can significantly protect plant growth under salinity stress. Seaweed extract increased the amount of proline and potassium in the leaves of the plant and thereby reduced the harmful effects of salinity stress on the borage plant. In addition, foliar spraying of borage plant with the use of seaweed extract increased the amount of chlorophyll in the plant, and in this way, by increasing the amount of photosynthesis in the plant; it helped the plant to grow better under salt stress conditions. The results of this research showed that the use of seaweed extract helps the plant to maintain its conditions against salt stress by increasing the amount of proline and absorbing potassium in the tissue. In addition, foliar spraying with seaweed extract preserves the structure of chlorophyll in the plant under salinity stress, and in this way, by increasing the photosynthetic efficiency, it helps the plant grow better under salt stress. According to the obtained results, it can be concluded that the use of seaweed can reduce the negative effects of salinity stress in the seedlings of Iranian borage. In addition, due to its low price and availability, it can be used as a suitable bio-fertilizer to protect plant growth under salinity stress conditions.
Growing vegetables
Farhad Shakarami; sadegh Mousavi-Frad; Abdolhossein Rezaei Nejad; Farhad Beiranvand
Abstract
Introduction
Salinity in water and soil stands as a crucial environmental factor that significantly hampers global agricultural production. Over recent decades, the escalating demand for irrigation in arid and semi-arid regions has intensified this issue, making it a major agricultural challenge. Salinity ...
Read More
Introduction
Salinity in water and soil stands as a crucial environmental factor that significantly hampers global agricultural production. Over recent decades, the escalating demand for irrigation in arid and semi-arid regions has intensified this issue, making it a major agricultural challenge. Salinity stress, characterized by reduced water absorption, heightened salt uptake (especially sodium, chlorine, and boron), and the generation of reactive oxygen species, induces oxidative stress in plants, severely impacting their growth and overall performance. To enhance plant tolerance to salinity stress, elicitors are employed as a short-term and viable solution to mitigate the adverse effects of stress. Copper, serving as a cofactor and essential element for numerous enzymes involved in photosynthesis and respiration processes, plays a crucial role in sustaining natural plant growth and metabolism. Copper ions function as cofactors in enzymes like superoxide dismutase (Cu/Zn SOD) and polyphenol oxidase, contributing to the removal of reactive oxygen species. However, the absence of this element in plants cultivated in alkaline and saline soils of arid and semi-arid regions can lead to nutritional disorders. In this context, copper nanoparticles emerge as a suitable alternative to chemical fertilizers due to their quicker and more efficient impact. Their use not only mitigates the negative consequences of excessive fertilizer application but also reduces the frequency of application. The Persian leek (Allium ampeloprasum subsp. Persicum) is a valuable edible-medicinal plant native to Iran, belonging to the Amaryllidaceae family. It holds significance in Iran as a key leafy vegetable, valued for its freshness and high processing potential among horticultural plants. Given the nutritional and medicinal importance of Persian leek and the prevalence of salinity stress, this study aims to explore the impact of copper nanoparticle spray in modifying the effects of salinity stress on the morphophysiological and biochemical characteristics of Persian leek.
Materials and methods
A factorial experiment was conducted using a completely randomized design with three replications in the research greenhouses of Lorestan University's Faculty of Agriculture. The experimental conditions included daytime temperatures ranging from 20 to 28 °C, nighttime temperatures from 15 to 20 °C, relative humidity set at 60-70%, and a light intensity of 400-500 µmol m-2 s-1. The first factor involved foliar spraying of copper nanoparticles at control levels (zero), 150, and 300 mg/liter, while the second factor comprised salinity stress at control levels (zero), 50, 100, and 150 mM sodium chloride. F1 seeds were obtained from Pakan Bazr Company and planted in 1.5-liter pots, with each pot containing three plants. The copper nanoparticles were applied through foliar spraying twice on the shoot parts at the four-leaf and six-leaf stages. Salinity stress was introduced one week after the foliar application, implemented through irrigation once every three days at a level corresponding to 90% of the field capacity. The soil mixture comprised an equal ratio of agricultural soil, cow manure, and sand, maintaining a clay-sand loam texture. Following three months of applying salt stress, a comprehensive assessment of morphophysiological characteristics was carried out. This included the measurement of plant height, stem and bulb diameter, leaf count, fresh and dry weights of stem, root leaf, root volume and length, shoot/root ratio, dry matter (%), stress tolerance index, relative water content (RWC), electrolyte leakage, malondialdehyde content, photosynthetic pigments, chlorophyll stability index, as well as the activity of peroxidase and ascorbate peroxidase.
Results and Discussion
The results indicated that salinity stress had a detrimental impact on various aspects of plant growth, including a decrease in plant height, stem and bulb diameter, leaf number, and the fresh and dry weights of the stem, bulb, and root. Additionally, there was a reduction in root volume and length, along with decreased levels of photosynthetic pigments. The percentage of electrolyte leakage, malondialdehyde content, and the activity of antioxidant enzymes, namely peroxidase and ascorbate peroxidase, also increased, highlighting the adverse effects of salinity stress on plant development. The decline in plant growth can be attributed to multiple factors, including diminished cell division, ionic imbalance, reduced water absorption, impaired uptake of essential elements, and the impact of toxic ions, particularly sodium and chlorine. Other contributing factors include impaired absorption, regeneration, and metabolism of nitrogen and protein, as well as stomatal closure, collectively resulting in reduced photosynthetic efficiency. Salinity stress further leads to a reduction in soil water potential and an increase in the osmotic pressure of the soil solution. Consequently, the plant requires more energy to absorb water from the soil, leading to increased respiration and alterations in the hormonal balance of plant tissues, ultimately causing a decrease in growth and negative effects on the plant. The application of copper nanoparticles at both concentrations demonstrated positive effects on various growth components, including plant height, stem and bulb diameter, leaf count, and the fresh and dry weights of the stem, bulb, and root, as well as increased root volume and length. Additionally, the use of copper nanoparticles resulted in a decrease in the percentage of electrolyte leakage and malondialdehyde content, coupled with an increase in the concentration of photosynthetic pigments and the activity of antioxidant enzymes, including peroxidase and ascorbate peroxidase. Notably, the concentration of 150 mg/liter exhibited a more pronounced effect in enhancing plant growth, with a diminishing impact observed at higher concentrations. Copper \nanoparticles improve plant growth under stress conditions by influencing the content of cellular antioxidants and modulating the hormonal balance of plant tissues.
Conclusion
The findings of this study indicated that increased salinity stress led to higher electrolyte leakage and malondialdehyde content, along with a reduction in RWC and photosynthetic pigments. These changes caused a decline in the morpho-physiological characteristics of Persian leek. However, salinity stress also increased the activity of peroxidase and ascorbate peroxidase enzymes. Foliar application of copper nanoparticles under these conditions had beneficial effects on the plants. Specifically, at a concentration of 150 mg/liter, the negative effects of salinity stress on the morpho-physiological indices of Persian leek were alleviated. This improvement was due to an increase in the activity of antioxidant enzymes, RWC, and the concentration of photosynthetic pigments.
Pomology
Sayeede Khodaei; Ebrahim Ganji Moghaddam; Mahbube Zamanipour
Abstract
IntroductionSince Iran is one of the arid and semi-arid regions of the world and due to the great importance of water in agriculture, it is very important to conduct research to improve drought stress in order to produce more quality products. In this regard, this study was conducted to investigate the ...
Read More
IntroductionSince Iran is one of the arid and semi-arid regions of the world and due to the great importance of water in agriculture, it is very important to conduct research to improve drought stress in order to produce more quality products. In this regard, this study was conducted to investigate the effect of mycorrhiza species on some morphological and physiological characteristics of peach seedlings under drought stress. Arbuscular mycorrhizal fungi coexist with the roots of various plants and have a broad effect on their growth. These fungus are effective in the initial establishment of the plant under drought conditions. Arbuscular mycorrhizal fungi increases plant resistance to dehydration by increasing growth and uptake of nutrients, especially phosphorus. Matherials and MethodsIn order to investigate the effect of three species of Arbuscular mycorrhizal fungi on some vegetative characteristics and phosphorus absorption of peach seedlings under drought stress conditions, a factorial experiment was conducted based on a randomized complete block design with four replications. The experimental factors included: drought stress at four levels (100, 80, 60 and 40 percent of field capacity) and the second factor application of mycorrhizal fungus at four levels: application of three species of mycorrhiza fungi and three species of fungi, each in three concentration (75, 100, 125 g in a pot) with chemical fertilizer (100 g triple super phosphate for each pot) and fertilizer (without mycorrhiza) and control (without fertilizer and mycorrhiza). The measurements were comprised root traits, stem diameter, vegetative growth of branches, leaf area index, vegetation index, relative leaf water content, chlorophyll fluorescence, leaf electrolyte leakage, leaf phosphorus and colonization root percent. Results and DiscussionResult showed that application of mycorrhizal fungi seems to be effective in reducing the effects of dehydration stress. The use of these fungi had a positive effect on reducing leaf electrolyte leakage under severe dehydration. According to the results obtained in this experiment, the highest efficiency in drought stress conditions was observed in G. mosseae and G. intraradices. Under drought stress conditions, the lowest values of root volume, greenness index, chlorophyll fluorescence, leaf electrolyte leakage, root colonization and leaf phosphorus content were observed. With increasing of drought stress, all of the mentioned traits reduced and mycorrhiza fungi had a positive significant effect on all studied traits. In this study, it was found that with increasing stress intensity, the traits were negatively affected and led to irreparable damage to the product. Therefore, it is expected that by preventing or minimizing the effects of stress, an effective step was taken to increase performance. The significant decrease in root colonization with increasing stress is probably due to the decrease in the growth of hyphae. The most important step after spore germination is the growth of hyphae resulting from germination, which plays an essential role in root colonization. Apparently, hyphae growth is more affected by osmotic potential than spore growth. The results obtained from this research showed that the roots of peach seedlings have significant symbiosis potential with arbuscular mycorrhizal fungi (Peymaneh & Zarei, 2013). According to Miyashita et al. (2005) Leaf photosynthesis activity can be used as a useful tool for classification of drought tolerant plants. Sajjadinia et al. (2010) regarding the relative water content and photosynthesis of several pistachio cultivars reported high correlation and high diversity in different stages and cultivars and stated that the decrease in relative water content strongly reduces transpiration, stomatal conductance and photosynthesis, which our results are consistent. With the escalation of tension, the greenness index also decreased; So that in the conditions of severe stress (40% of crop capacity), the amount of greenness index reached the lowest value. In the conditions of severe stress due to interruption of continuous irrigation, the plants entered from the stage of mild stress to the stage of severe dry stress, which seems that under these conditions, the decrease in the concentration of chlorophyll, in addition to the decrease in the amount of synthesis, is caused by the decomposition of chlorophyll due to the increase in the amount chlorophyllase, peroxidase and phenolic compounds. According to Schutz and Fangmier (2001), the decrease in the amount of chlorophyll in stress conditions is related to the increase in the production of oxygen radicals in the cell. These free radicals cause peroxidation and as a result the decomposition of this pigment. The greenness index is considered one of the most important growth parameters, which is reduced by drought stress conditions, and the results indicate that the treatment of mycorrhizal fungi in all three types of inoculated mushrooms has improved the greenness index and the adverse effects It has removed the drought stress to a great extent (Figure 6), which can be attributed to the improvement of water and food absorption by mycorrhizal roots (Larsson et al., 2008). Conclusion In general, this study showed that the best treatment related to the mycorrizha fungi was mosseae, which had the most effect on reducing the negative effects of stress
Growing vegetables
Leyla Cheheltanan; Saeed Khosravi; Hosein Nemati
Abstract
IntroductionGrasses are narrow-leaved plants that are used as cover plants in landscape. These plants are one of the basic and necessary components of the green cover of most gardens, parks and as the background color of landscape. In Iran, due to the high costs of planting and management of grass, high ...
Read More
IntroductionGrasses are narrow-leaved plants that are used as cover plants in landscape. These plants are one of the basic and necessary components of the green cover of most gardens, parks and as the background color of landscape. In Iran, due to the high costs of planting and management of grass, high water requirements, climatic incompatibility and damage to water and soil salinity, it is recommended to remove from the green space in some cities, especially in areas with low water and water and soil saline. If it is possible to benefit from the role and influence of these plants by observing the technical points and choosing the best species for each area. Salinity stress is the second limiting factor for the growth of plants in the world after drought, which affects the efficiency and performance of plants. Increase in salinity causes a decrease in the water potential in the soil. In this condition, the plant spends most of its energy to maintain the water potential, cell mass, and water absorption to have minimal growth. The aim of this research is the effect of external application of glycine betaine on the accumulation of osmolality compounds and the antioxidant system of sports grass under salt stress. Materials and MethodsThis research was done in factorial form in completely randomized design with 3 replications on Rashid variety cucumber. The factors included 4 levels of temperature (25, 30, 35 and 40 degrees Celsius) and 3 levels of salicylic acid (0, 0.5 and 1 mM). When the seedlings reached the two-leaf stage, they were sprayed with different concentrations of salicylic acid two times with an interval of five days. One week after the application of salicylic acid, temperature treatment was gradually applied. After applying each heat treatment, the corresponding pots were transferred to the greenhouse with a temperature of 25 degrees Celsius. Then, fresh and dry weight of root and shoot, leaf surface, chlorophyll index, electrolyte leakage, proline, polyphenol oxidase enzyme activity and superoxide dismutase enzyme activity were measured. Results and Discussion The results showed that salinity stress decreased all the study morphological, physiological and biochemical parameters including plant height, shoot fresh and dry weight, number of tiller, leaf area, chlorophyll content, protein and total antioxidant capacity in the studied plants. It also increased peroxidase enzyme, H2O2 and proline in plants, but glycine betaine application significantly improved the morpho-physiological characteristics of plants compared to the control under salt stress conditions. Thus, the highest height, shoot fresh and dry weight, leaf area, number of tiller, chlorophyll content, and protein and antioxidant capacity were observed in plants sprayed with glycine betaine. Also, the highest content of glycine betaine and activity of catalase and peroxidase enzymes and the lowest content of glycine betaine and H2O2 were observed in in plants sprayed with glycine betaine and 10 mM glycine betaine was more effective than 5 mM. The occurrence of salinity in plants disrupts the absorption of ions and causes the reduction of nutrients and increases sodium ions. One of the effects of salinity in plants is the reduction of photosynthetic activity, which results in the reduction of chlorophyll, carbon dioxide absorption, photosynthetic capacity, plant height, shoot fresh and dry weight, number of tiller and leaf area. One of the most strategies to deal with stress is accumulation of osmolyte and increasing the antioxidant activity, which makes plants resistant to environmental stresses. Salinity, through the toxic effect of Na+ and Cl- ions, affects the growth and performance of the plant by reducing the soil water potential, disrupting water absorption and imbalance of nutrients in the plant. The results obtained from comparing the average results of glycine betaine show that glycine betaine increased plant height, shoot fresh and dry weight, number of tiller, leaf area, chlorophyll content, total protein and antioxidant capacity, but on the other hand, it increased proline and H2O2 decreased, which is due to the accumulation of glycine betaine as a protector in plants under salt stress conditions. In stress conditions, glycine betaine can protect photosynthetic activities including photosynthetic enzymes, proteins and lipids in thylakoid membranes in the combination of photosystem II, and also the task of protecting cell membranes against osmotic stresses in the plant. ConclusionThe results obtained from this research showed that salinity stress reduced all the morphological, physiological and biochemical characteristics in the sport grass plants, but glycine betaine application played a positive role in reducing salinity damage and maintaining plant quality. Glycine betaine is known as one of the effective molecules in stress signaling, so it can protect the plant cells against stress by reducing the destruction of the membrane and by increasing the salt tolerance mechanisms. Also, glycine betaine 10 mM is introduced as the best treatment to reduce salinity damage in sport grass during present study.
Postharvest physiology
M. Rahemi; M.H. Nazaran; S. Abolghasemi; S. Sedaghat; M. Zare
Abstract
Introduction
Low temperature storage is the most important method used to preserve harvested products. Keeping products at low temperatures, above the freezing point up to 10 degrees Celsius, can cause frost damage in fruits and vegetables, especially tropical and subtropical products. The use of heat ...
Read More
Introduction
Low temperature storage is the most important method used to preserve harvested products. Keeping products at low temperatures, above the freezing point up to 10 degrees Celsius, can cause frost damage in fruits and vegetables, especially tropical and subtropical products. The use of heat treatments as safe, organic and alternative physical methods is increasing, these treatments are used to maintain the quality after harvesting and also to prevent frostbite of garden products. Also, one of the recommended methods to reduce fruit waste is to increase the calcium concentration of the fruit by using calcium solutions. Calcium is one of the most important mineral elements that is involved in determining the quality of the fruit and its shelf life. Studies conducted on the use of nano fertilizers in some species of fruit trees has shown their potential role in improving the yield of the product and the physical and chemical properties of the fruitThis study was conducted to investigate the effect of postharvest treatments of calcium chloride and nano chelated calcium fertilizers on chilling injury and physiological characteristics of local orange fruits stored at 2 ±0.5° C and 85% relative humidity for 60 to 120 days.
Materials and Methods
In this research, orange fruits of the local cultivar Citrus sinensis at the stage of commercial maturity based on the taste index (10TSS/TA⋍) were prepared from Darab city of Fars province and transferred to the Physiology Laboratory of Horticultural Sciences Department of Shiraz University. Then the fruits were disinfected with 2% sodium hypochlorite and washed with distilled water. Treatments included calcium chloride and nano chelated calcium fertilizers at different concentrations of zero, 3 and 6 dissolved in cold water (20°C) and hot water at 45 °C for 25 and 15 min, respectively. Sampling was done on days 60 and 120. To simulate shelf life conditions, before measuring the parameters, the fruits were kept at laboratory temperature for two days. In this research, the changes in fruit tissue firmness, freezing index, weight loss percentage, soluble solids, total acidity, ascorbic acid, ion leakage, potassium ion leakage, malondialdehyde, calcium content of fruit skin and flesh, fruit color, catalase enzymes and peroxidase were measured. Data analysis was done using SAS software version 4.9 and comparison of averages was done by LSD test at 5% probability level.
Results and Discussion
There was a significant difference between nano chelated calcium and calcium chloride in calcium enrichment in pulp and fruit skin Calcium chloride and nano chelated calcium treatments dissolved in hot water reduced weight loss, soluble solids content, acidity, ascorbic acid, ion leakage and malondialdehyde and the activity of the antioxidant enzymes catalase and peroxidase. Nano chelated calcium increased calcium content by 44% in fruit skin and up to 41% in fruit pulp compared to calcium chloride. Nano chelated calcium 3 and 6 % showed more stability in fruit weight (159 and 400%, respectively) compared to calcium chloride after two months of storage. After 60 and 120 days of storage, the content of ascorbic acid in fruits treated with 6 nano chelated calcium was 73% higher than calcium chloride. Nano chelated calcium 3 % compared to calcium chloride prevented 39.6 of potassium ion leakage during 60 days of storage. The amount of ascorbic acid in the 3% and 6% nano calcium treatment and the tissue hardness in the 3% nano calcium chelate treatment after two months of storage were estimated to be higher than the control and calcium chloride. Calcium nano chelate 6% improved the calcium content of fruit flesh and skin due to increased permeability. Warm water pretreatment with calcium compounds is an efficient and recommendable treatment for the preservation of orange fruits in cold storage conditions due to the improvement and reduction of the severity of the increase in indicators related to the occurrence of frost damage in the skin of fruits.
Conclusion
One of the primary concerns during storage is the loss of fruit weight. Calcium nano chelate, in comparison to the control and calcium chloride treatments, exhibited the least weight loss over the two months of storage. This is attributed to the critical role of calcium in influencing the shelf life of fruits. It was observed that immersing fruits in calcium compounds dissolved in hot water and utilizing 6% nano chelated calcium had a significant positive impact on enhancing and preserving the quality of orange fruits during cold storage.
Pomology
M. Fattahi; A. Mohammadkhani
Abstract
Introduction
UCB-1 hybrid rootstock is propagated from the seed of a controlled cross between a P. atlantica female and a P. integerrima male. Clonal propagation of this rootstock is also necessary since it produces identical genotypes. UCB1 has recently been introduced in Iran. However, little ...
Read More
Introduction
UCB-1 hybrid rootstock is propagated from the seed of a controlled cross between a P. atlantica female and a P. integerrima male. Clonal propagation of this rootstock is also necessary since it produces identical genotypes. UCB1 has recently been introduced in Iran. However, little research has been done on this subject. Water stress is one of the most important environmental stresses and occurs for several reasons, including low rainfall, high and low temperatures, salinity, and high intensity of light, among others. Drought stress is a multidimensional stress and causes changes in the physiological, morphological, biochemical, and molecular traits in plants. Proline is also found widely in plants and accumulates in large quantities in response to environmental stresses such as drought. It is the essential amino acids that accumulate in different tissues of the plant, especially in the leaves through the effect of water stress, and that the accumulation of it has a function in the regulation of osmosis in the cell as the proline is increased in the cytoplasm to counterbalance effort osmosis cell sap. Proline is an indicator of water stress tolerance and its increase in the leaf proof that the plant suffered drought stress, also is the way the plant tolerance to drought stress.
Materials and Methods
A pot experiment was conducted, to investigate the effectiveness of foliar applied proline in mitigating the concurrent effects of drought stresses on UCB1 rootstock, at greenhouse of Faculty of Agriculture, University of Shahrekord. Experiment was carried out in a completely randomized design with split arrangement having three replications. Chl. and carotenoid contents were determined according to Lichtenthaler (1987). Leaf discs were obtained from expanded leaves of each pot in the morning. The leaf discs were weighed immediately to obtain the fresh weight (FW), and submerged in distilled water for 4 h at 4◦C in dark condition and then weighed to prepare turgor weight (TW). The leaves were dried in a forced-air oven at 70◦C for 24 h, and the dry weight (DW) was recorded. The RWC of samples was calculated using the following equation (Bastam et al., 2012): RWC = [(FW–DW)/(TW–DW)] × 100
Levels of glycine betaine were quantified as described previously by Arakawa et al. (1990). To determine the free-proline concentration, leaves were homogenized in 5 ml of ethanol at 95%. Proline concentration was calculated with a standard curve and expressed as µg g−1fresh mass (Paquin and Lechasseur, 1979).
Results and Discussion
The UCB1 proximate analysis in the present study depicted that imposition of drought stress increased the leaf and root proline content and electrolyte leakage. Exogenous application of proline as foliar spray significantly increased the moisture content of leaf and root, RWC, Chl a and total chlorophyll. Exogenous proline application upregulated leaf and root proline contents and decreased the lipid peroxidation (decrease electrolyte leakage), resulting into improvement in chlorophyll contents. 150 mg. l-1 proline application gave maximum alleviation against stress.
Numerous reports depict that the exogenous application of proline as a foliar spray can play an important role in enhancing plant tolerance against drought stress, and our results are consistent with them. This ameliorating effect of exogenously applied proline can take the form of osmoprotection, cryoprotection, or protection against reactive oxygen species.For example, in various plant species growing under stress conditions, exogenously supplied proline provided osmoprotection and facilitated plant growth. Normally, proline accumulation in plants, is in response to drought or salinity stress occurs in the cytosol where it contributes substantially to the cytoplasmic osmotic adjustment. It actively takes part in plant osmotic adjustment under stressful environmental conditions. In addition to its role as an osmolyte for osmotic adjustment, it actively takes part to stabilize subcellular structures, biological membranes, proteins, and scavenge free radicals. It also plays a vital role in buffering cellular redox potential under stressful environmental conditions.
Conclusion
In summary, our results showed that, drought induces a decrease in moisture content, RWC, T Chl and carotenoids and an increase in some osmoregulators (proline, glycine betaine, TSC). The most favorable treatment was 150 mg.l-1 proline foliar spray. 150 mg.l-1 proline application gave maximum alleviation against stress. Foliar application increased the moisture content of leaf and root, as well as increased the Chl a, total, RWC and proline content of leaf and root. It can be suggested that the foliar application of proline (150 mg L-1) used as a plants defense factor against drought stress conditions.
Growing vegetables
M. Ghoreyshi; F. Nekounam; T. Barzegar; J. Nikbakht
Abstract
Introduction
Water stress is the most prominent abiotic stress limiting agricultural crop growth and productivity. Deficit irrigation stress as a consequence of the progressive decrease in water availability has been a hot topic regarding food security during the last two decades. Growth and development ...
Read More
Introduction
Water stress is the most prominent abiotic stress limiting agricultural crop growth and productivity. Deficit irrigation stress as a consequence of the progressive decrease in water availability has been a hot topic regarding food security during the last two decades. Growth and development of plants is influenced by reduction in turgor that results in decreased nutrient acquisition from dry soil. When water supply is limited, plant growth and yield is reduced and plant structure is modified by decreasing in leaf size. The effect of deficit irrigation on fruit yield and quality has been reported by numerous researchers with different results. In melon, deficit irrigation reduced marketable fruit number and yield, average fruit weight, fruit diameter and did not affect rind thickness and seed cavity, but increased total soluble solids content. Although the effects of water stress have been studied on growth and yield of different crops during the last years, recent information on the response of African horned cucumber yield and quality to deficit irrigation remains limited, particularly about the results of restricted water distributions in arid and sub-arid environments. The main goal of this study was to evaluate the effect of controlled deficit irrigation on growth, physiological parameters and yield and fruit quality of African horned cucumber.
Material and Methods
Field experiment was performed based on a completely randomized block design with three irrigation regimes (60, 80 and 100 %ETc), whit three replications at Research Farm of University of Zanjan during the 2019. The African horned cucumber seeds were sown on 1th July 2020 at recommended spacing of 50 cm in row with 120 cm between rows. The irrigation system consisted of one drip line every crop row. The three irrigation levels were calculated based on actual evapotranspiration (ETc): (1) control, irrigated 100% crop water requirement, (2) deficit irrigation 80% ETc and (3) deficit irrigation 60% ETc. The Water requirement of the plant for control treatment was estimated using long-term average daily data of meteorological parameters recorded at Zanjan Meteorological Station and following relation. Before starting the differential irrigation at five-leaf stage, all treatments were supplied with similar amount of water to maximize stands and uniform crop establishment. During plant growth, the relative water content, proline content, electrolyte leakage, chlorophyll and carotenoids, P and K contents were measured. After fruit harvest, vine length of each plant, leaf dry weight and stem diameter were measured. The fruits were harvested when color changed from green to yellow. Fruit weight, fruit number per plant and fruit yield per plant was measured. Immediately after harvest, fruit firmness, total soluble solid, total phenols content, antioxidant capacity and vitamin C were determined.
Results and Discussion
As the results showed water deficit stress significantly reduced plant length, chlorophyll content, and increased carotenoids content. Based on the findings, deficit irrigation caused a significant reduction in leaf relative water content. According to the results, phosphorus and potassium contents in African horned cucumber leaves decreased with deficit irrigation treatments. The highest P and K contents were found under irrigation 100 %ETc treatment. Drought stress and associated reduction in soil moisture can decrease plant nutrient uptake by reducing nutrient supply through mineralization. The proline content increased with the deficit irrigation treatments; in particular with sever deficit irrigation (60 %ETc). Mean comparisons of data showed that deficit irrigation led to a significant increase in electrolyte leakage compared to control.
Water deficit stress caused significant reductions in yield. The highest fruit number per plant and yield were obtained under irrigation 100% ETc. The average fruit weigh significantly increased in response to increase water deficit stress. Deficit irrigation treatments significantly decreased vitamin C and fruit firmness. Significant differences among irrigation treatments were observed for total phenols and total soluble solid contents. The phenols and total soluble solid contents increased with the decrease of irrigation water applied. Antioxidant capacity was affected significantly by the irrigation treatments, and water deficit stress increased antioxidant capacity, which no significant difference was observed between irrigation 100 and 80 %ETc.
Conclusion
Water deficit has been shown to adversely affect plant growth, fruit yield, and leaf water status of African horned cucumber, but led to increase the TSS and antioxidant capacity. According to the results, fruit yield reduced 13.9 % under irrigation 80% ETc compared to irrigation 100% ETc, However, water consumption was saved by 20% and improved fruit weight and fruit quality with increasing soluble solids and antioxidant capacity.
Pomology
Sh. Sorori; A. Asgharzade; A. Marjani; M. Samadi
Abstract
Introduction Drought is one of the most important environmental stresses. It limits crop production in the world and has adverse impacts on growth of plants and their metabolic processes. By changing some of the metabolic processes, drought stress changes the behaviour of plants and, eventually, ...
Read More
Introduction Drought is one of the most important environmental stresses. It limits crop production in the world and has adverse impacts on growth of plants and their metabolic processes. By changing some of the metabolic processes, drought stress changes the behaviour of plants and, eventually, makes them resistant to some stresses. Given the water crisis in Iran, and since most of the available water is used in the agriculture sector, there is a need to change the current cropping pattern. The substitution of low-water-use for high-water-use plants could be an important water management strategy. Every physiological and biochemical factor involved in water conservation in plants is an effective factor in introducing tolerant varieties.Materials and MethodsThe required chemicals ( 80% acetone, 95% ethanol, ninhydrin, glacial acetic acid, benzene, proline, pure glucose, anthrone, sulfuric acid, potassium phosphate, polyvinylpyrrolidone [PVP], EDTA, hydrogen peroxide and guaiacol) were purchased from the Merck Company. This study was carried out in the spring and summer of 2019 in the Research Greenhouse of Islamic Azad University of Bojnourd. The rooted cuttings of 18 dominant grape varieties in the region (Kolahdari, KajAngoor, Fakhri, sefid Beryan, Divaneh, Sahebi, La’l, Siyah, Shiregi, Garmeh, Khalili, SanjariKajAngoor, Keshmeshi, Ghareghat, Maskeh, Asgari, Flame Seedless and White Seedless) were planted in plastic pots with a diameter of 35 cm and a height of 40 cm. The soil was a mixture of blown sand, leaf litter, and garden soil in the 1:1:1 ratio. Before the experiment, all pots were irrigated to reach field capacity.The factorial experiment was conducted using completely randomized design with three replications. The first factor was irrigation cessation (15-day drought stress) and control (irrigation to field capacity level). The second factor was variety (18 varieties).To apply the stress condition, irrigation cessation continued until leaf wilting signs were appeared. Based on previous experience, the duration of tolerance to drought stress was approximately 2 weeks. During the experiment, the minimum and maximum greenhouse temperatures were, respectively, 18.5 °C and 34 °C and natural light was used.Results and Discussion The results of analysis variance showed that drought stress significantly increased the amount of electrolyte leakage (6.29), and activities of peroxidase (0.056 katal per ml) and catalase (0.92 katal per ml). It also decreased leaf relative water content (61.95%), relative chlorophyll content (16.85) and contents of chlorophyll a (3.45 mg/g), chlorophyll b (1.12 mg/g) and carotenoids (2.84 mg/g).Grape varieties respond differently to drought stress and, in general, water scarcity reduces their leaf RWC and chlorophyll contents. According to Schutz and Fangmier (2001), a decrease in chlorophyll content under stress conditions is because of an increase in the production of oxygen radicals in the cell. These free radicals can cause peroxidation and decomposition of the pigments. The intensity and greenness of the leaves reduce with decreasing the chlorophyll concentration and accelerating the process of aging.Reduced greenness of the leaves under long-term stress conditions may be partially due to reduced nitrogen flow into the tissues and changing activities of such enzymes as nitrate reductase. Since nitrogen is a constituent of a chlorophyll molecule, its deficiency in plants may slow down the formation of chlorophyll. Lawlor and Cornic (2002) showed the effectiveness of carotenoid, as an auxiliary pigment, in protecting thylakoid membranes and preventing chlorophyll photo-oxidation. Drought stress increases the activity of the peroxidase and catalase enzymes in both drought-sensitive and -resistant varieties; however, the activity of antioxidative enzymes is significantly higher in the stress-resistant varieties.The studied cultivars were divided into the three groups include of tolerant (White Seedless, Garmeh, Maskeh, Flame Seedless, Fakhri, Khalili and Divaneh), semi-susceptible (Kolahdari, Sefid Beryan, Sahebi, Laal, Shiregi, Kaj Angoor Sanjari and Asgari) and sensitive (Siah, Ghare-Ghat, Kaj Angoor Sanjari and Keshmeshi) cultivars to drought stress. Among the studied cultivars, White Seedless had the highest levels of relative leaf water (77.81%), relative chlorophyll content (28.62), carotenoids (4.81 mg/g) and the lowest amount of electrolyte leakage (31.5) and Garmeh the highest chlorophyll a (6.64 mg/g) and chlorophyll b (2.12 mg/g) contents and peroxidase (0.0618 katal per ml) and catalase activities (0.959 katal per ml).Conclusion The grape plant adaptation to drought stress is the result of changes in many morphological, physiological, and biochemical mechanisms, which cause changes in the rate of electrolyte leakage, leaf RWC, proline content, soluble solids, speed of photosynthesis, enzymatic activities, etc. The results showed that the white seedless variety had the highest leaf RWC, relative chlorophyll content, carotenoid content, and the lowest electrolyte leakage. Besides, Garmeh variety with the highest chlorophyll a and b, peroxidase, and catalase contents is amongst the most resistant varieties.
M. Sadat Farizani; H.R. Khazaee; ali gazanchian
Abstract
Introduction: Beautification of urban space and creating attractive face for cities by development of green space has caused to capita of urban green space be introduced as an important factor in urban development. Meanwhile, the important role of cover plants, especially turf grass, in creating green ...
Read More
Introduction: Beautification of urban space and creating attractive face for cities by development of green space has caused to capita of urban green space be introduced as an important factor in urban development. Meanwhile, the important role of cover plants, especially turf grass, in creating green spaces has caused to add quickly the area of these beautiful plants in the cities. Nevertheless, existence of plants with high water requirements between the turf grasses, have created limitations in terms of water requirements supply. The grass planted in the country is mainly from imported seed types that are not so compatible with dry and semi-arid conditions in our country and from this point of view, sometimes they create limitations in terms of water supply. One of the native grasses in the country, is Tall Fescue (Festuca arundinaceous), which is a variety of cool-season, perennial and herbaceous grasses. One of the strategies to preserve grass under drought stress is improving soil structure with the aim of increasing the moisture. Organic compounds that improve soil physical and biological conditions (such as municipal waste compost and manure) can be effective. Using compost improves soil structure and strengthens soil mineral content and allows soil to retain moisture for longer. Because compost can hold water about two to six times its volume and prevent it from being wasted. Compost in heavy soils, improves soil porosity and makes the soil better ventilation elderly. In light soils, it acts like a sponge and by keeping water and food safe, it will greatly prevent them from being washed. Therefore, present research was done to evaluate the effect of mixing different amounts of Municipal Solid Waste (MSW) compost with soil on some physiological properties of Tall Fescue native grass under moisture stress conditions.
Materials and Methods: This research was conducted in the form of two experiments in research greenhouse of Ferdowsi University of Mashhad. The first experiment with aim of evaluating percentage and rate of grass emergence was conducted in a completely randomized design with four replications that the experimental treatments consisted of ten different levels of compost mixing with soil (10 up to 100 t.ha-1) and control treatment (agronomic soil without mixing compost). In the second experiment, three values of 70, 80 and 90 tons of compost per hectare plus control (no compost consumption) as the first factor and three levels of moisture stress of 25, 50 and 100 percent of field capacity as intense stress, mild stress and without stress, respectively as the second factor that were compared in factorial by a completely randomized design with four replications.
Results and Discussion: The results of the first experiment showed that the amounts of 70, 80 and 90 tons per hectare increased significantly the percentage and rate of grass emergence due to increased fertility and higher water holding capacity and in these treatments, the positive effect of rising water holding capacity has been dominated on negative effect of electrical conductivity of the soil and this topic has led to an improvement in the percentage of grass emergence in these treatments. Furthermore, in the amounts of 70, 80 and 90 tons of compost per hectare, the bulk density of soil significantly decreased and the C/N ratio dramatically increased. In the second experiment, with increasing drought stress in different amounts of compost, the total chlorophyll content decreased and relative water content of plant, proline and electrolyte leakage increased. In the compost treatment of 90 tons per hectare, due to its high ability to store water, the cell membrane integrity was more preserved and it was done less understanding of stress. The shoot dry weight decreased significantly as a result of increasing the severity of drought stress.
Conclusion: Based on the findings of this study, application of 90 tons of compost per hectare significantly improved some of physiological traits for Tall Fescue grass in drought stress conditions. Also, it seems that Tall Fescue grass cleverly has tried to deal with drought stress with target of increase the amount of moisture available for itself. Therefore, using 90 tons of compost per hectare for Tall Fescue grass in low water conditions and occurrence of moisture stresses is recommended.
yahya selahvarzi; S. Sarfaraz; M. Zabihi; M. Kamali
Abstract
Introduction: Drought is known as one of the most important factors limiting the growth and production of plants in urban landscape. Drought has limited production of 25% of the world's agricultural lands. Water allocated to the landscape irrigation has high value and should be used optimally ...
Read More
Introduction: Drought is known as one of the most important factors limiting the growth and production of plants in urban landscape. Drought has limited production of 25% of the world's agricultural lands. Water allocated to the landscape irrigation has high value and should be used optimally with high efficiency. Soil texture is a classification instrument used both in the field and laboratory to determine soil classes based on their physical texture. Soil texture can be determined using qualitative methods such as texture by feel, and quantitative methods such as the hydrometer method. Soil texture has agricultural applications such as determining crop suitability and predicting the response of the soil to environmental and management conditions such as drought or calcium (lime) requirements. Soil texture focuses on the particles that are less than two millimeters in diameter which include sand, silt, and clay. Soil texture affects the water content and drainage ability of soils. This is because texture controls the nature of soil pores, i.e. the voids or spaces between the mineral particles in a clay soil. For example, there are many minute pores or micro pores between the tiny clay particles. Being small, they tend to retain water but to exclude air. As a result, clay soils are prone to drain poorly and to become waterlogged. By contrast, sandy soils are dry soils. On the other hand, application of new techniques to maintain soil moisture is essential. One of these techniques for increasing soil water retention is use of natural moisture absorbing materials such as zeolite. Zeolites are one of the new and effective substances to improve the soil water retention and preserve water and minerals in the soil. Zeolites contain elements such as potassium, calcium, sodium, silicon, aluminum, magnesium, iron and phosphorus that can be considered as the best dietary supplement and fertilizer and play an important role in the utilization and production of the most agricultural products. Ligustrum vulgar L., belongs to the Oleaceae family, is native to warm regions, European and Asian countries including Iran. This plant is one of the most widely used perennial plants in the landscape spaces. This study was designed to investigate the effects of drought stress and soil texture on growth and some qualitative and quantitative traits of the Ligustrum vulgare. Materials and Method: In order to investigate the effect of zeolite and soil texture on quantitative and qualitative traits of Ligustrum vulgare under drought stress, a factorial experiment was conducted based on completely randomized design with three replications, in the greenhouse of Agricultural Faculty, Ferdowsi University of Mashhad in 2019. The treatments consisted of four types of soil texture (100% soil, 100% sand, 80% soil + 20% zeolite, 80% sand + 20% zeolite) and three levels of irrigation (25, 50 and 100% field capacity). Plant height, number of leaves, number of lateral branches, maximum root length, root volume, shoot and root dry weight and length of lateral branches were measured in each pot. Physiochemical traits such as relative water content, electrolyte leakage and photosynthetic pigments were also measured. Statistical analysis of data was analyzed by JMP8 software. Graphs were plotted using excel and all mean comparisons were performed by LSD test at p < 0.05%. Results and Discussion: According to the results, decreasing irrigation levels reduced vegetative traits such as fresh weight and dry weight. Relative water content also decreased, but ion leakage increased by decreasing irrigation levels. The highest stem fresh weight (18 g), root fresh weight (29 g), total fresh weight (56 g) and total dry weight (20 g) were observed in soil + zeolite, and the highest leaves fresh weight, root volume and plant height were obtained in soil and soil + zeolite treatments. The lowest root volume was observed in sand and zeolite treatments which had no significant differences. In addition, ion leakage was lower in the treatments containing zeolite than the other treatments. The highest amount of SPAD (72) and chlorophyll b (31.5 mg / g fresh weight) were observed in sand + zeolite treatment and 25% field capacity. According to the results, it seems that soil and soil + zeolite in low irrigation conditions were more suitable environment for growth of Ligustrum vulgare and sandy bedding would reduce plant growth in normal conditions as well as under drought stress.
H. Nastari Nasrabadi; S.F. Saber Ali
Abstract
Introduction: Melon (Cucumis melo L.) is one of the most important vegetables in Cucurbitaceae family and one of the most important economic crops in the Torbat-e Jam city (Longitude: 60 ̊48', latitude: 35 ̊31', altitude: 928 m). Growth and yield of agricultural crops are affected by biotic ...
Read More
Introduction: Melon (Cucumis melo L.) is one of the most important vegetables in Cucurbitaceae family and one of the most important economic crops in the Torbat-e Jam city (Longitude: 60 ̊48', latitude: 35 ̊31', altitude: 928 m). Growth and yield of agricultural crops are affected by biotic and abiotic environmental stresses. Cold stress can be one of the most important environmental factors reducing crops yield. Cold acclimation in plant is a complex process involving many morphological, physiological and biochemical changes, including a significant reduction in tissue hydration during cold hardening. Melatonin (MEL, N-acetyl-5-methoxytryptamine) is a conserved substance, which has been discovered in all living organisms, from bacteria to mammals. MEL regulates the growth of root, shoot, and explant, activates seed germination and rhizogenesis, and delays leaf senescence. In addition, the most frequently mentioned functions of MEL are related to various abiotic stresses such as drought, radiation, low/high temperature, heavy metals, and salinity stresses. Materials and Methods: In order to investigate the effect of PEG priming and melatonin on cold stress resistance of melon seedlings, a factorial experiment was conducted in a completely randomized design with three replications in Torbat-e-Jam University. In this experiment polyethylene glycol 6000 was used to produce drought stress at three levels (0, 0.18 and 0.58 MPa) and melatonin was used at two levels (0 and 200 μmol). When melon seedlings were at 4 leaf stage, the amount of polyethylene glycol was added to the irrigation solution for a week and to prevent drought stress, drought stress was increased for 3 days and increased one third of the required concentration daily. Recovery was performed for three days after drought stress and during this period melatonin was added to the irrigation solution at the required concentration. Seedlings were then exposed to cold stress (T0: non-stress and T1: cold conditions). Control plants were kept in greenhouse conditions. Results and Discussion: Comparison of the mean results showed that there was an increasing trend in proline production by increasing drought stress. The highest amount of proline (0.80 µmol g-1 FW) was recorded at the highest level of drought pretreatment with no melatonin and without cold stress (D2M0T0), and then a decreasing trend in proline production was observed. The results showed that melatonin significantly increased leaf relative water content compared to the control. Interaction effects of drought pretreatment and temperature showed that there was a trend of decrease in relative water content by increasing drought pretreatment. Ghanbari and Sayyari (8) reported that drought pretreatment stress maintains relative water content of tomato seedlings under cold stress conditions. Drought pretreatment significantly reduced the amount of chlorophyll a and total chlorophyll. The results showed that the highest levels of drought pretreatment stress (D2) and melatonin (M1) maintained chlorophyll a under cold stress conditions. Results showed that the amount of chlorophyll b was decreased by drought pretreatment stress, but it increased by melatonin application in all compounds. Based on the results, it was found that only simple effects of treatments at 1% of probability level had significant effects on soluble sugars content. Comparison of the mean simple effects of drought pretreatment showed that under drought stress the amount of soluble sugars increased significantly and the highest sugar content was recorded at the highest drought stress level. The amount of soluble sugars in plants under cold stress also increased significantly. Melatonin application also significantly increased the amount of soluble sugars. Kabiri et al. (19) reported that the use of melatonin increased soluble sugars in Moldavian balm seedlings under osmotic stress which is similar to this study results. It was found that melatonin significantly increased phenolic compounds under stress conditions and significantly decreased electrolyte leakage.
H. Farhadi; M.M. Sharifani; M. Alizadeh; H. Hokmabadi; Sasan Aliniaeifard
Abstract
Introduction: Agriculture of Iran is known worldwide for its pistachio (Pistacia vera L.) and is one of the most important non-oil exports. Therefore, attempts to improve the yield can be one of the primary goals in the pistachio industry in Iran. Due to the drought problem in Iran, increasing the cultivation ...
Read More
Introduction: Agriculture of Iran is known worldwide for its pistachio (Pistacia vera L.) and is one of the most important non-oil exports. Therefore, attempts to improve the yield can be one of the primary goals in the pistachio industry in Iran. Due to the drought problem in Iran, increasing the cultivation area to increase production may not be a good option. Therefore, the purpose of this study was to compare the drought tolerance of different pistachio seedlings from open pollination and pollinated with domestic species pollen and controlled crosses using integerrima pollen in order to find the most tolerant genotypes.
Materials and Methods:
The first step: Controlled pollination and hybrid seed production In order to produce hybrid seeds, a controlled pollination using integerrima pollen grains at Razavi Pistachio Research Institute was conducted for five cultivars; Ahmad Aghaei, Akbari, Sorkheh Hosseini, Garmeh and Fandoghi. Each replication had a tree and from each tree, seven branches were selected that had at least three to four flower buds and four branches from it for controlled pollination, two branches for open pollination and a branch was considered for negative control. Before the flower clusters were fully opened, 70% alcohol was sprayed on the branches to prevent the possibility of unwanted pollen. In order to ensure controlled pollination, in the bud swelling stage, the branches were isolated by double-layered bags measuring 30 × 45 cm. Pollen was collected from the Arzooieh area of Kerman province to select the male parent of integerrima. Then, a combination of flour and integerrima pollen (1:1 ratio) was injected into the insulating bags and pollination was performed. In late summer, hybrid seeds were harvested.
The second stage: Drought resistance test of hybrids obtained from first step The experiment was conducted as factorial based on a Completely Randomized Design with four replications at the research greenhouse located in Gorgan University of Agricultural Sciences and Natural Resources during 2019-2020. The treatments were consisted of ten pistachio genotypes; Ahmad Aghaei, Akbari, Sorkheh Hosseini, Garmeh, Fandoghi and (hybrids between integerrima as the pollinizer and genotypes of Ahmad Aghaie, Akbari, Sorkheh Hosseini, Garmeh and Fandoghi were applied as the maternal parent and three levels of drought including control (field capacity), mild stress (65% of field capacity) and severe stress (30% of field capacity) were applied on 3 months old seedlings for 84 days. Seeds obtained from free and controlled pollination were planted in pots with a diameter of 33 cm and a height of 35 cm on April 6, 2017. Three seeds were planted in each experimental unit, and after planting and ensuring establishment, the number of plants in the pot was reduced to the final level of one in each pot. Each replication was consisted of four experimental units or four pots, and each pot was contained a plant. At the end of the experiment, growth and physiological parameters were measured. Statistical analysis of the results was performed using SAS 9.1 software.
Results and Discussion: Results of statistical analysis showed drought stress had a significant effect on leaf number, stem length, root length, leaf relative water content, electrolyte leakage, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, and leaf and root proline content. With increasing drought levels, all traits except root length, electrolyte leakage and proline content were reduced in comparison with control. Sorkheh Hosseini × integerrima, Ahmad Aghaei × integerrima, Akbari × integerrima interactions and genotypes of fandoghi and fandoghi × integerrima interaction were superior in the most of traits by drought, respectively. Based on the results it seems hybrids of Sorkhe Hosseini × integerrima, Ahmad Aghaei × integerrima and Akbari× integerrima crosses will be used as genotypes with dry-tolerant genes to modify cultivars in arid regions.
F. Dezhabad; M. Haghighi
Abstract
Introduction: Most plants, especially those that are native to hot areas, show signs of injury when exposed to low temperatures. Damages caused by cold stress occurs at the cell and organs level, which reflects it at the plant surface. Color change, chlorosis, general reduction of growth, cellular tissue ...
Read More
Introduction: Most plants, especially those that are native to hot areas, show signs of injury when exposed to low temperatures. Damages caused by cold stress occurs at the cell and organs level, which reflects it at the plant surface. Color change, chlorosis, general reduction of growth, cellular tissue destruction, non-absorption of nutrients, reduction of photosynthesis, non-transferring photosynthetic materials are from early effects of cold stress. Cellular responses to colds including loss of thoracic pressure, vacuolization, collapse of cytoplasmic membrane balance, cytoplasmic flow loss, and general organ dysfunction. The susceptibility of the plant to frost is different depending on the type of plant, variety, tissue morphology and other cellular characteristics, as well as the cold conditions of the period, time and cold intensity. In addition, it seems that organs of the plant have different degrees of cold tolerance. If the temperature of the aerial part is favorable, the low temperature of the root zone can be one of the factors limiting the root system and plant growth. The consumption of balanced boron content by neutralizing the negative effects of cold stress and mechanisms such as maintaining the structure of the membrane, improving and increasing root growth, increasing the synthesis of proteins needed for the plant, adjustment of stomatal movements and improved stomatal conductance, increased cell division, increased nitrogen metabolism and chlorophyll production, and its consequence was increased photosynthesis and dry matter production, increased activity of antioxidants, calcium / potassium ratio adjustment, optimizing the transfer of calcium in the plant, adjusting the amount of water and conducting it in the cell, increasing the moisture content and relative content of leaf water, transferring soluble materials and increasing water use efficiency creates a relative resistance to low temperature stress. Although the root temperature is very effective in plant growth, it has been less attractive. Therefore, the aim of this study was to investigate the effect of low temperature of root and shoot on the ability to restore plant growth and physiological activity in the presence and absence of boron.
Materials and Methods: In order to compare the impact of sudden low temperature stress of root and shoot on recovery of vegetative and physiological traits of tomato, a research was conducted in two separate experiments under controlled conditions in the greenhouse of Faculty of Agriculture, Isfahan University of Technology. Two experiments were factorial based on completely randomized design with 10 replications including two concentrations of boron (0, 0.5, 1 and 1.5 in ppm) and two temperature levels of shoot and root sections (10 degrees’ Celsius temperature, and 11 rootstock temperatures and 22 ° C optimum and control temperatures). Indicators included photosynthesis rate, respiration rate, stomatal carbon dioxide, stomatal conductance, chlorophyll fluorescence, chlorophyll index, water use efficiency, proline, antioxidant, phenol secretion from root and leaf extracts, leaf relative water content, soluble protein concentration, ion leakage, leaf water potential, root and shoot dry weights and starch content. Finally, the analysis of the results was done by statistical software statistic and comparing the meanings by LSD test at 5% level.
Result and discussion: The results showed that the highest amount of photosynthesis, root dry weight and dry weight of the aerial part were in the consumption of 0.5 ppm of boron during abrupt stresses of low temperature on the root after the recovery period. The highest amount of stem proline and electrolyte leakage were also obtained from 0.5-1.5 ppm of boron consumption during abrupt low temperature on the shoot part. According to the results, it was found that when stress has entered from the root zone to the aerial part of the plant, the plant was in the better conditions after the recovery period. It seems that when a cold stress occurred on the roots, the plant can produced more antioxidant substances, including phenol and proline, while counteracting the relative water content of the leaves were more effective with radical agents. Thus, in normal conditions, the roots of the plant operated at a lower temperature than the airspace. They also exhibited more adaptations to the lower air at the lower temperature than the air section and the plant is less damaged. At levels above the boron element due to the effect of boron toxicity and the production of excess free oxygen radicals, the plant probably suffered more severe damage than cold damage.
Conclusions: Sudden low temperatures stresses on the root and shoot had negative effects on the recovery of the vegetative and physiological traits of tomatoes. When lower temperatures were imposed on the shoot, the plant suffered much more damages. Consumption of 0.5 ppm of boron during cold stress by creating optimal conditions for growth also caused the relative neutralization.
Y. Selahvarzi; M. Kamali; J. Nabati; H. Ahmadpour Mir
Abstract
Introduction: Each year, with the onset of cold season and severe drop in temperature, the probability of frost bite and frost damage is a problem for landscaping plants. Many plant species, especially tropical and subtropical species, are damaged when exposed to frostbite, causing damage to ...
Read More
Introduction: Each year, with the onset of cold season and severe drop in temperature, the probability of frost bite and frost damage is a problem for landscaping plants. Many plant species, especially tropical and subtropical species, are damaged when exposed to frostbite, causing damage to their cells, tissues, and organs. Research has shown that by altering membrane properties during cold stress, metabolic balance is disturbed and with the increase in toxic metabolites, secondary damage to the plant can occur. At low temperature, decreases the efficiency of energy transfer to the center of the photosystem II. In addition, low temperatures are the main cause of the formation of reactive oxygen radicals. Also, lowering the temperature in the presence of light, due to the imbalance between light absorption and photosynthesis, increases the risk of light oxidation. Low temperature also reduces the activity of Rubisco. The amount of free proline in many plants increases significantly in response to environmental stresses such as frost stress, and stabilizes the membrane during cold stress.On the other hand, the use of some organic materials such as organic mulches increase temperature of the soil, and thus helps plant from frostbite. Use of organic mulch is widespread in agriculture due to the positive effect in soil temperature, weed control and moisture retention. Also, these mulches are effective in height, growth and flowering, early maturity and total yield of the products. Mulches in the warm seasons reduces soil temperature. Use of mulch can also help plants to withstand frostbite. Organic mulch decomposition in appropriate temperature and humidity conditions, liberates the nutrients gradually and provides for root plant and microorganisms of the soil. Organic mulches can reduce the effect of salt toxicity on plant growth and actively increase soil desalination. The most important benefit of mulch is the increase in soil temperature in the seed area, which accelerates the growth and yield of the product. Use of straw as mulch resulted in accelerated germination in cucumber. Use of straw mulch leads to an increase in temperature at night, thus protecting plants from temperature stress that has a positive effect on the growth and development of wheat.
Material and methods: In order to investigate the effect of freezing stress and using different types of organic mulch for Aquilegia plant, this experiment was conducted as a factorial experiment based on completely randomized design with four replications at Faculty of Agriculture, Ferdowsi University of Mashhad. The experimental treatments included four types of mulch (control (without mulch), 50% soil + 50% manure, 50% soil + 50% leaf needle + 50% soil + 50% rice bran) and five levels of freezing temperature (0, -5, -10, -15 and 20). Characteristics such as percentage of electrolyte leakage, relative water content, chlorophyll index and total chlorophyll, leaves number, leaf area, plant dry weight and proline leaf content were considered.
Results and Discussion: The results showed with decrease of temperature from 0 to -20 °C, stem diameter, leaf area and leaf number in bran mulch treatment decreased by 42.6%, 73.4%, 21.2% respectively, also stem diameter, leaf area and leaf number in mulch of leaf needle were 35.2%, 9/64%, 47.6%, in manure mulch were 20.20%, 46.4%, 7.8% and in the control of mulch decreased, 32.8%, 79.7%, 30.7%, respectively. At -5 °C, the amount of proline was 26% in the leaf and at -20°C, the amount of proline increased 50% compared to the control. Also, the lowest proline (0.73 μmol / g fresh weight) was obtained from the plants that treated with bran mulch. With application of, electrolyte leakage reached 63.6%, 68%, 61% and 57% in control conditions bran, needle and manure, respectively. In short, the least electrolyte leakage was observed in manure. On the other hand, when temperature dropped from 0 to -20 °C, the percentage of electrolyte leakage increased in Aquilegia. Relative water content of the leaf were 24% at 0°C, 38% at -15 °C and 23% at -20 °C. In terms of non-use of mulch, the relative water content was 36% and reached a 42% and 40% with application of manure and needle using mulch. By measuring the total carbohydrate found in Aquilegia leaf, it was observed that the amount of this trait was increased under frost stress. In general, although frost stress reduced the morphological traits of Aquilegia, use of organic mulch resulted in the improvement of these traits. The best results were observed in manure mulch.
Maryam Kaamali; Mahmoud Shour; Seyyed Hossein Neamati; A Lakziyan; Hamidreza Khazaie
Abstract
Introduction: Water deficiency is one of important abiotic stresses that severely effects on plant growth. The effects of drought range from morphological to molecular levels and are evident at all phenological stages of plant growth at whatever stage the water deficit takes place. Growth is accomplished ...
Read More
Introduction: Water deficiency is one of important abiotic stresses that severely effects on plant growth. The effects of drought range from morphological to molecular levels and are evident at all phenological stages of plant growth at whatever stage the water deficit takes place. Growth is accomplished through cell division, cell enlargement and differentiation, and involves genetic, physiological, ecological and morphological events and their complex interactions. The quality and quantity of plant growth depend on these events, which are affected by water deficit. Cell growth is one of the most drought-sensitive physiological processes due to the reduction in turgor pressure. Under severe water deficiency, cell elongation of higher plants can be inhibited by interruption of water flow from the xylem to the surrounding elongating cells. Impaired mitosis, cell elongation and expansion result in reduced plant height, leaf area and crop growth under drought. Chlorophyll content is one of the major factors affecting photosynthetic capacity changing in chlorophyll content of plant under drought stress has been observed in different plant species and its intensity depends on stress rate and duration. Chlorophyll content of leaf is indicator of photosynthetic capability of plant tissues. In the mid-80s, RWC was introduced as a best criterion for plant water status which, afterwards was used instead of plant water potential as RWC referring to its relation with cell volume, accurately can indicate the balance between absorbed water by plant and consumed through transpiration.
Materials and Methods: To study the effects of drought stress on three varieties of petunia, a factorial experiment based on randomized complete block design with four replications was conducted. The treatments consisted of four irrigation levels ((100% control), 80%, 60% and 40% of field capacity) and three varieties of petunia (Supercascade, Tango blue and Tango white). After planting and transplanting and after full deployment in the pot, water stress treatments were applied on three varieties of petunias. At the end of each week fully blossomed flowers were counted, flower diameter, peduncle length and corolla length were measured. In order to determine the stability of the cell membrane electrolyte leakage index was measured. Specific leaf area (SLA) was determined. The amount of chlorophyll a, b, total and carotenoid and relative water content in the leaves were measured. Statistical analysis was performed using the software MSTAT-C. EXCEL was used for diagramming software. Means were compared using LSD test with a 0.05 significance level.
Results and Discussion: Results indicated that interaction impacts of variety and irrigation on dry weight, leaf area, flower number, flower diameter, length Corolla, chlorophyll content, electrolyte leakage, relative water content and proline content was significant. The most shoot dry weight (76/1 g) was in control stress (100% FC) and Tango White variety. Also the most leaf dry weight (07/2 g) and root dry weight (g 43/0) were in Tango Blue variety. With increasing drought stress from 100% FC to 40% FC, leaf area decreased in Supercascade from 314 to 49, in Tango Blue from 405 to 44 and in Tango White from 459 to 69 cm2. In 80% FC, electrolyte leakage increased in all varieties (Supercascade variety 2%, Tango Blue 10% and in Tango White 3%) compared to control. Also electrolyte leakage increased in Supercascade 17%, in Tango Blue 9% and in Tango White10% in 40% FC compared to control. Comparison of interaction effects of drought stress and variety also showed the most proline had accumulated in Tango White and drought 40% of field capacity and then in Tango Blue and stress 40% of field capacity. Generally two varieties of Tango Blue and Tango White in control irrigation had better growth and also in low irrigation were more resistant.
shadan khorshidi; Gholamhossein Davarynejad; leila samiei; mohammad moghaddam
Abstract
Introduction: Most deciduous trees need low temperature to break flower bud dormancy. One of the most important abiotic stresses is low temperature which limits production of temperate fruits. Pear production has been considerably reduced in recent years. Important pear cultivars show different levels ...
Read More
Introduction: Most deciduous trees need low temperature to break flower bud dormancy. One of the most important abiotic stresses is low temperature which limits production of temperate fruits. Pear production has been considerably reduced in recent years. Important pear cultivars show different levels of resistance to cold. Cold compatibility followed by resistance increase is controlled genetically and contains several mechanisms which lead to production of different metabolites such as: polypeptides, amino acids and sugars. The object of this research was to evaluate the frost resistance of different ‘Dare Gazi’ genotypes and other pear cultivars in Mashhad climate condition.
Materials and Methods: This study was conducted to investigate the frost resistance of 23 ‘Dare Gazi’ pear genotypes and nine other cultivars include: ‘William’s’, ‘Bell de june’, ‘Spadona’, ‘Koshia’, ‘Domkaj’, ‘Torsh’, ‘Sebri’ and ‘Tabrizi’. Plant material contained vegetative and reproductive buds of one-year-old shoot samples which were collected from 25-year old trees on March 2014, four days after winter cold (-6.6 °C) in three directions of trees and sent to the laboratory. Frost damages of vegetative and reproductive buds were investigated based on visual observations (%), electrolyte leakage (EC) and proline content. EC was measured with a Metrohm 644 digital conductivity meter and proline content was measured based on Bates et al. (1973) method, using acid ninhydrin. The experiment was performed on completely randomized experimental design with three replications. Statistical analysis was carried out using MSTAT-C and Excel software. Mean values were compared using the least significance difference test (LSD) at 1% levels. Cluster analysis was conducted by SPSS 16 program.
Results and Discussion: Highest EC of reproductive buds was observed in ‘Dare Gazi’ 10, 19, ‘Tabrizi’ and ‘Torsh’ whereas ‘Dare Gazi’ 8, 18 and ‘Bell de June’ had the lowest EC. Based on visual observations, the least percentage of damaged reproductive buds was observed in ‘Dare Gazi’ 22 while ‘William’s’ suffered from frost at the highest damage level (96%). Göndör and Tóth (1998) studied 13 pear cultivars by microscopic observations of flower buds and found that ‘Packham's Triumph’ was relatively resistant under Hungarian ecological conditions. Honty et al. (2008) reported that Kaiser was the most sensitive pear cultivar to low temperatures during endodormancy and ecodormancy. Khorshidi et al. (2014) described that pear reproductive buds of ‘Ghodumi’ were the most tolerant. Considering the vegetative buds, ‘Dare Gazi’ 19 had the highest EC (74.47 %) which was not significantly different from ‘Dare Gazi’ 10, 20 and 3 whereas the lowest one was found in ‘William’s’(24.75%). The highest percentage of healthy vegetative buds was found in ‘Dare Gazi’ 1 (50%) which did not show a significant difference with ‘Dare Gazi’ 12, 5 and 7. ‘Tabrizi’ was the most sensitive and had most damaged vegetative buds (95.99%). Khorshidi et al. (2014) observed the least damaged vegetative buds in ‘Dare Gazi’ and the most damaged buds in ‘Boheme’ and ‘Ghodumi’. Palonen and Buszard (1997) mentioned that hardiness of woody tissue of apples did not seem related to flower bud hardiness. The highest proline content of reproductive buds was found in ‘Dare Gazi’ 20 (21.28 µmol g-1FW) and the lowest content observed in ‘Dare Gazi’ 2 (0.1 µmol g-1 FW). Young (1977) described that increase in proline was not correlated well with relative cold hardiness of citrus rootstocks. Data did not show any significant correlation between EC and proline content. Barka and Audran (1997) studied grape buds and shoots and reached a high negative correlation between proline content and frosttolerance. Yelonsky (1979) indicated that accumulation of proline was not correlated to cold hardiness. The results of present experiment were in agreement with Duncan and Jack (1987) findings which reported that increase in proline was not always correspondent to cold resistance. Based on the cluster analysis, the genotypes laid in two distinct groups. First group included ‘Dare Gazi’1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 17, 18, 19, 20, 23 and ‘Sebri’, ‘Domkaj’, ‘Bell de june’ and ‘Koshia’ and second group include ‘Dare Gazi’ 11,16, 21 and ‘William’s’, ‘Spadona’ and ‘Torsh’. Frost damage, EC and proline content were higher in the first group compared to second group.
Conclusion: Cosidering‘DareGazi’ genotypes, no correlation was found between proline content and frost damage rate. This shows that morphological differences among ‘Dare Gazi’ genotypes could be due to the existing of genetic variation of these genotypes or they are different clones of one cultivar.
Gholam Hossein Davarynejad; S. Shirbani; M. Zarei
Abstract
Introduction: The amount of water available to plants includes one of the most important factors that affect the growth of plants. The objective of the present study was to investigate and compare the tolerance of different fig types (Ficus carica L.) to different low irrigation treatments.
Materials ...
Read More
Introduction: The amount of water available to plants includes one of the most important factors that affect the growth of plants. The objective of the present study was to investigate and compare the tolerance of different fig types (Ficus carica L.) to different low irrigation treatments.
Materials and Methods: A factorial trial based on a completely randomized design with 3 replications was carried out in Ferdowsi University of Mashhad. The treatments of this experiment were four levels of irrigation including; supplying enough water to pots (100% field capacity), mild stress (75% field capacity), average stress (50% field capacity) and severe stress (25% field capacity) on Green, Black, Shah Fig and Matthew cultivars. Some of morphological and physiological traits like stem growth, leaf umber, leaf area, root length, root area, fresh and dry weight of shoot and root, root to shoot ratio, relative water content, electrolyte leakage, total chlorophyll and proline were measured.
Results and Discussion: According to the results, significant differences were observed between different irrigation treatments for all measured parameters. The highest level of stem growth, leaf umber and leaf area were detected in control treatment (100% field capacity), while the lowest contents were observed in severe stress (25% field capacity). The results showed that the fresh and dry weight of shoot and root decreased with increasing drought stress, so that the lowest amounts were observed in severe stress treatment (25% field capacity). The levels of relative water content was significantly affected by different irrigation treatments, since treated plants with severe stress treatment (25% field capacity) had the lowest relative water values, while the highest levels was observed in control treatment (100% field capacity). The highest and lowest of total chlorophyll content was observed in control treatments (100% field capacity) and severe stress (25% field capacity), respectively. Among the study treatments, severe stress treatment (25% field capacity) had the highest amount of root length, root area, root to shoot ratio and control treatment had the lowest root length, root area, root to shoot ratio. The obtained results detected that electrolyte leakage increased with increasing drought stress. The severe stress treatment (25% field capacity), had the highest proline content, followed by the average stress treatment (50% field capacity), while the lowest value was observed in control (100% field capacity). A variation in terms of all measured parameters also was observed among the cultivars and the differences were statistically significant. Among the presently tested cultivars, Black has the best resistant ability to drought stress than in other cultivar.
Conclusion: This research showed all measured parameters were significantly affected by irrigation treatments and cultivars. These data demonstrated that cultivar was the main parameter which influences the morpho-physiological properties in figs.
M. Ghfouri; A. Soleimani; V. Rabie; R. Hemmati
Abstract
Introduction: Due to high quality, Iran pomegranate is quite competitive compared to other countries is unrivaled among agricultural products and has great economic importance. Using essential oil is a new idea to reduce postharvest losses and increase the horticultural crop storage life and control ...
Read More
Introduction: Due to high quality, Iran pomegranate is quite competitive compared to other countries is unrivaled among agricultural products and has great economic importance. Using essential oil is a new idea to reduce postharvest losses and increase the horticultural crop storage life and control of fungal infection. In this context, a factorial experiment based on completely randomized design was conducted to study the postharvest spraying of thyme essential oil on storage life and qualitative characteristics of pomegranate fruit (cv. Tarom red skin)
Materials and Methods: Pomegranate fruit (cv. Tarom red skin) was prepared and transferred to University of Zanjan, Horticulture postharvest physiology lab. Treatments were included essential oil of thyme at four levels (0, 500, 1000, 1500 mg/l) and the cold time storage (6 °C and 85% of relative humidity) at three levels (one, two and three months (by four replications. In the first experiment, 180 normal pomegranate fruits were treated with thyme essential oil. In the second experiment, fruits were infected with spores of the fungus Aspergillus niger and then treated with essential oil. During experiment, total soluble solids (TSS), titratable acidity (TA), TSS/TA ratio, pH, anthocyanin, electrolyte leakage, chilling injury, weight loss and fungal decay were evaluated. Fruit juice TSS was determined with a hand-refractometer at room temperature. TA was determined by titration an aliquot (20 mL) of the juice with 0.1 N NaOH and the results were expressed as a percentage of citric acid. The maturity index (TSS/TA ratio) was evaluated as the TSS/TA ratio. Fruit juice pH was measured using a pH meter. Anthocyanin was performed to method Fuleki & Francis. Electrolyte leakage was measured according to McCollum & McDonald method. Weight loss was measured according to Ershadi method. Chilling injury was measured by Wang method. Decay was visually evaluated and expressed as percentage. An analysis of variance was used to analyze difference between treatments and the Duncan test was applied for mean separation at p
rozita khademi astaneh; Seyed Jalal Tabatabaie; saheb ali bolandnazar
Abstract
Selenium is a non metallic chemical element that affects plant growth and development and but it can due to the presence of antioxidant defense system as a matter of basic human and animal health has been identified. An experiment was conducted to study the effect of Se on physiological characteristics ...
Read More
Selenium is a non metallic chemical element that affects plant growth and development and but it can due to the presence of antioxidant defense system as a matter of basic human and animal health has been identified. An experiment was conducted to study the effect of Se on physiological characteristics and yield of Brussels sprouts (Brassica oleracea var. Gemmifera) with six levels of Se (0, 2, 4, 8, 16 and 32 mg/l) from sodium selenate. The experiment was arranged in a completely randomized design with four replications under greenhouse conditions. The results showed that yield in terms of fresh weight of sprout was significantly (P≤0.01) affected by Se concentration so that increasing Se concentration from 0 to 8 mg/l increased the yield and chlorophyll index, electrolyte leakage (EL) in leaves decreased then with increasing Se concentration decreased the yield and EL in young leaves increased. The highest yield was observed at 8 mg/l Se concentration that was 40% higher compared to the control treatment. With increase concentration of Se in the nutrient solution increased Se concentration and as follow old leaves>young leaves> sprouts. The results showed that Se can be added at the 8 mg/l to the nutrient solution for growing Brussels sprout.
H. Rastegari; Ali Tehranifar; Seyyed Hosein Nemati; M. R. Vazifehshenas
Abstract
To investigate the effect of different concentrations (0, 0.01% and 0.02%) of salicylic acid (SA) on some quantitative and qualitative characteristics of pomegranate fruit cultivar ‘Malase Yazdi’ at ripening,2 and 4month ofstorageat5°C, a factorial experiment based on randomized complete block with ...
Read More
To investigate the effect of different concentrations (0, 0.01% and 0.02%) of salicylic acid (SA) on some quantitative and qualitative characteristics of pomegranate fruit cultivar ‘Malase Yazdi’ at ripening,2 and 4month ofstorageat5°C, a factorial experiment based on randomized complete block with three replications was conducted. Quantitative characteristics including percentage of fruit weight loss, percentage of healthy arils, aril paleness percentage, and fruit quality characteristics including percentage of skin browning and white segments separating the arils (membrane), electrolyte leakage (EL), juice pH, titrable acidity, total soluble solids, antioxidant activity, juice ascorbic acid content and fruit taste index were measured. The results showed that with time until two month of storage, the weight loss of fruit had happened, but then the rate of weight loss reduced. With SA application percentage of healthy arils and aril paleness increased. The lowest and highest percentage of membrane browning was related to concentration of 0.01% of SA after two month of storage (14.8%) and control fruits after four months of storage (96.6%), respectively. SA in 0.02% concentration reduced EL at harvest but with time the EL increased so that SA could not prevent EL increases after 4 month of storage. Also fruit taste index reduced with increasing in SA concentration. Over time and during storage titrable acidity, total soluble solids, juice PH and browning percentage increased significantly while ascorbic acid decreased.
A. Nezami; Seyed Mmohammad javad Mousavi; S. Nezami; E. Izadi Darbandi; M. Yousef Sani; fatemeh keykha akhar
Abstract
Calendula (Calendula officinalis) is relatively cold tolerant plant, but in some years plant seriously injured due to harsh winter. In order to evaluate freezing tolerance of calendula an experiment was carried out at college of Agriculture, Ferdowsi University of Mashhadin a factorial-completely randomized ...
Read More
Calendula (Calendula officinalis) is relatively cold tolerant plant, but in some years plant seriously injured due to harsh winter. In order to evaluate freezing tolerance of calendula an experiment was carried out at college of Agriculture, Ferdowsi University of Mashhadin a factorial-completely randomized design with three replications and plants of two sowing dates (summer and autumn) were exposed to12 temperatures (0, -2, -4, -6, -8, -10, -12, 14- ,16-, -18, -20 and -22oC). Seeds of calendula plants were sown in summer (summer plant) and autumn (autumn plant) in the bed and in six to eight-leaf stages were transplanted to the pots. After the cold acclimation in natural condition, freezing stress was applied with using a thermo gradient freezer. To employ stability of cytoplasmic membrane, percentage of electrolyte leakage (EL%) was measured after freezing. Also survival percentage (Su%) and regrowth of calendula plants determined after three weeks recovery. Leaves EL% in autumn plants was significantly more than summer plants and autumn plants have higher Su%, but plant height, number of lateral branches, numbers of reproductive traits, total dry matter, vegetative and reproductive dry matter in summer plants were more than autumn plants. However, there were no difference between calendula plants for LT50el in both autumn and summer plants, but there was significant difference between them for LT50su and total dry matter, and LT50su and reduced dry matter temperature50 (RDMT50)for summer plants were -18.6 oC and -11.3 oC and for autumn plants were -19.4 oC and -13.7 oC, respectively.
M. Mahmoodnia; Mohammad farsi; S.H. Marashi; P. Ebadi
Abstract
Investigation of the cultivated tomato plant as a plant ideal system along with the drought resistant wild species can be useful to a better understanding of the mechanisms of drought resistance and improvement of tomato plants. To investigate the effect of drought stress on leaf Relative Water Content ...
Read More
Investigation of the cultivated tomato plant as a plant ideal system along with the drought resistant wild species can be useful to a better understanding of the mechanisms of drought resistance and improvement of tomato plants. To investigate the effect of drought stress on leaf Relative Water Content (RWC), electrolyte leakage and photosynthetic parameters in four species of tomato (a cultivated species and three wild species) at two levels of irrigation (field capacity and 40% field capacity) and four time periods (before stress, 10 days after stress, 20 days after stress and recovery) a factorial experiment based on Completely Randomized Design (CRD) was used. Among the tested species, cultivated species showed the highest decrease in RWC. Electrolyte leakage was significantly increased in stress conditions. The rate of photosynthesis and chlorophyll fluorescence yield in the two drought resistant wild species increased in stress conditions unlike of cultivated species, probably because of more adaptation of these species with low water conditions. The results showed that each of these species according to their own mechanism for dealing with drought stress, in one or more properties are superior to other species. it is therefore suggested that the different species for future studies (molecular) with different characteristics to be used.
