Pomology
Esmaeil Khaleghi; Masumeh Zamani Dehbari; Noorollah Moallemi
Abstract
IntroductionCitrus fruits are one of the most commercial fruit products in the world, whose growth and production are affected by abiotic stresses. Drought stress is one of the most important abiotic stresses that affects all the vital processes of the plant. One of the ways to moderate the negative ...
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IntroductionCitrus fruits are one of the most commercial fruit products in the world, whose growth and production are affected by abiotic stresses. Drought stress is one of the most important abiotic stresses that affects all the vital processes of the plant. One of the ways to moderate the negative effects of drought stress is the use of polyamines. Polyamines are a group of biochemical compounds that are used as one of the most effective compounds to resist environmental stresses. Polyamines have a wide role in various plant growth processes, such that they play a significant role in modulating various types of biotic and abiotic stresses. Studies have shown that application of putrescine increases the fresh and dry weight of the shoot and root parts, leaf relative water content, photosynthetic pigments, leaf surface, and photosynthesis in plants under drought stress. Materials and MethodsThis study was conducted to investigate the effect of different levels of putrescine (0, 0.5, 1 and 2 mM) and different levels of irrigation (100, 75 and 50% of evotranspiration potential) on morpho-physical traits of lime seedlings as a factorial experiment based on randomized complete block design with 3 replications.Two-year-old lime seedlings were obtained from a commercial nursery located in Dezful city (approved by the Khuzestan Agricultural Jihad Organization). Then, they were located in 15-kilogram pots and kept for 2 months in the greenhouse to adapting to the environmental conditions. In order to apply the irrigation regime, 4 pots were considered as reference plants and the amount of irrigation water was determined by weighing these pots. First, the weight of reference pots was calculated in field capacity mode. Then, after 7 days, the pots were weighed again and the difference between the primary and secondary weights was considered as the amount of irrigation water of 100% plant evaporation and transpiration, and according to that, 75% irrigation and 50% evaporation and transpiration potential were applied. The first foliar spraying with putrescine was done at first of March in Field capacity (foliar spraying was done once every month for 4 months from March to June). At the end of the experiment, the fresh and dry weight of root and shoot, number of leaves, relative water content, leaf water potential, photosynthesis, transpiration, stomatal conductance, were measured. Statistical data analysis was done using MSTATC software and, Duncan's multi-range test was used to mean comparation at the 5% probability level. Results and DiscussionResults showed that the rate of photosynthesis, stomatal conductance, relative water content of leaves, fresh and dry weight of aerial part and root decreased by reducing the amount of irrigation from 100 to 75 and 50%, of ETcrop. The reduction of growth parameters under drought stress can be due to the closing of the stomata and the reduction of carbon dioxide emission into the leaves, which can lead to lower levels of chlorophyll and photosynthesis, induction of oxidative stress, and finally less growth in plants. It has also been stated that the decrease in growth caused by drought stress in the initial stages of the stress can be due to the decrease in cell growth and development due to the decrease in turgor pressure and the decrease in the intensity of photosynthesis due to the closing of stomata. Also, the results showed that foliar spraying with 2 mM putrescine increased photosynthesis, stomatal conductance, relative water content of leaves, wet and dry weight of aerial parts and roots at all irrigation levels. The researchers believed that the increase in growth parameters, relative water content and photosynthetic pigments with putrescine foliar spraying can be related to the antioxidant properties of putrescine and its osmolality role in dry conditions. Other researches have shown that putrescine may modulate certain ion channels and increase the permeability of the membrane to calcium and cause a decrease in the entry of potassium into the membrane, which causes a decrease in the exit of water from the cell. Also, putrescine may increase leaf water potential and leaf content through osmotic regulation of the plant by increasing proline. ConclusionIn general, the results showed that foliar spraying of putrescine, especially at 2 mM concentration has the greatest effect on increasing growth parameters, including fresh and dry weight of shoots and roots, leaf area, increasing the relative water content, leaf water potential and Gas exchanges and reducing the amount of ion leakage under drought stress conditions.
N. Moallemi; E. Khaleghi; Z. Jafari zadeh
Abstract
Introduction: Plant establishment is difficult in some arid and semi-arid regions of Iran because of lacking rainfall and inadequate distribution and extreme heat. Previous studies stated that plant water parameters and growth characteristics such as plant height, fresh and dry weight of root, stem and ...
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Introduction: Plant establishment is difficult in some arid and semi-arid regions of Iran because of lacking rainfall and inadequate distribution and extreme heat. Previous studies stated that plant water parameters and growth characteristics such as plant height, fresh and dry weight of root, stem and leaf, which is known as the first reaction of plants, were decreased under drought stress. Therefor it is necessary to use practices with objectives to decease the effects of drought stress on plants and increasing water use efficiency. Several studies showed that various morphological and physiological characteristics in plants were influenced by ascorbic acid. In fact, ascorbic acid increased plant resistance to drought stress. The purpose of this research was to investigate the effect of ascorbic acid application on growth traits of ‘Baghmalek’ olive under 100%, 66% and 33% ETcrop < /sub> by analyzing growth traits and relative water content, stem water potential and stomata resistance. Material and Methods: This research was carried out in order to assess the effects of three levels of water deficit (100, 66 and 33 percent of evapotranspiration (ETcrop < /sub>)) and four concentrations of ascorbic acid (0, 250, 500 and 750 mg l-1) on some growth and physiological parameters of young olive plants cv. ‘Baghmalek’as a factorial experiment based on a randomized complete block design with three replications. Fresh and dry root, stem and leaf weight, leaf number, leaf area, stem diameter, relative water content, stem water potential and stomata resistance were measured in this research. Two years old olive trees (Olea europaea cv. ‘Baghmelak’) were used. Seventy two plants were grown in 10 L pots, containing a mixture of field soil: sand: manure (1:1:1). Plants were sprayed with four concentrations of ascorbic acid and irrigated every 10 days, based on the amount of evapotranspiration of plant (ETcrop < /sub>). Parameters such as relative water content, stem water potential and stomata resistance were measured at last week of the experiment and the other parameters were measured every week. Data analysis were performed using MSTATC software and means comparison were carried out by Duncan's multiple range test (DMRT) at 5% and 1% of probability levels. Results and Discussion: The results indicated the growth quality was better in plants treated with 250 mg l-1 ascorbic acid under water stress. Fresh and dry weight of root, stem and leaf growth, stem diameter, leaf number, leaf area were higher in plants treated with 250 mgl-1 ascorbic acid than untreated plants. Interaction between water deficit stress ×ascorbic acid revealed information in plant characters such as fresh and dry weight, stem diameter and leaf area simply declined as sources of water (from 100 to 66 and 33 percent) become limited, in particular in the trees which not receiving ascorbic acid treatments. However, application of 250 and 500 mg l-1 ascorbic acid enhanced the amount of relative content of leaf and water potential of stem in trees under water deficit stress. While stomata resistance was decreased in trees receiving ascorbic acid treatments. Some researcher declared that limitation of photosynthesis could be one of the most important factors for decreasing growth under water deficit stress. In addition, relative water content, cell turgor potential, reduced cell division, cell enlargement and growth plant could be affected by water deficit stress. Also the results indicated that leaf area (5952 cm), leaf number (151.7), stem diameter (6.49 mm), stem length (63.33 cm), root dry weight (18.16 g) and leaf fresh weight (9.35 g) were obtained in irrigated plants with 33% ETcrop < /sub> and untreated with ascorbic acid. Our results showed leaf number (158.7), stem length (74 cm), root fresh weight (78.08 g), stem fresh and dry weight (46.45 and 28.43 g, respectively) and leaf fresh and dry weight (13.35 and 8.45 g, respectively) were highest in irrigated plants with 100% ETcrop < /sub> and treated with 250 mg l-1 ascorbic acid. Conclusion: Water deficit stress could affect directly on relative water content, cell turgor potential and reduce cell division, cell enlargement, plants photosynthesis and plant growth. The use of ascorbic acid could effect on plants resistance to drought. In addition, various morphological and physiological traits could be influence by ascorbic acid. The results of this research indicated that 250 mg l-1 ascorbic acid concentration had more effects on water deficit and it seems ascorbic acid can be used to reducing the negative effects of drought in some regions that rainfall shortage and drought is important problems.
Reza Gholami; noorollah moallemi; Esmaeil Khaleghi; Seyyed Mansour Seyyednejad
Abstract
Introduction: Olive tree (Olea europaea L.) is one of the most important fruit crops that, has a huge economic price. The plant is significant in the Mediterranean countries and Iran for table olive and oil. The nutritional requirements of olive are much lower than those of other fruit trees, but shortfall ...
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Introduction: Olive tree (Olea europaea L.) is one of the most important fruit crops that, has a huge economic price. The plant is significant in the Mediterranean countries and Iran for table olive and oil. The nutritional requirements of olive are much lower than those of other fruit trees, but shortfall in these needs costs tree important physiological disorder. Fertilization, especially Potassium and micronutrients is a cultivation technique that strongly affects the productivity of olive trees. The amount of oil and fruit quality is effected by the correct nutrition. Leaf spraying is an important tool for correcting food deficiencies and improving the quality of the fruit of the planted olive trees under unsuitable conditions, which provides nutrients directly and as soon as possible to the branches and leaves, or fruit. Studies have shown that leaf feeding with potassium, boron and zinc can be useful for increasing the qualitative and qualities characteristics of fruit in most products, especially in arid and semi-arid regions. Thus, the present study was aimed to assessing the effect of zinc sulphate, boric acid and potassium sulphate foliar application on oil content and the qualitative and quantitative characteristics of fruit of three olive, “Caillet”, “Koroneiki” and “Mission” cultivars in unfavorable temperature conditions in Ahwaz.
Materials and Methods: This study was carried out to investigate the effect of foliar spraying of Potassium, Boron and Zinc on the oil content and the qualitative characteristics of the fruit of three olive, “Caillet”, “Koroneiki” and “Mission” cultivars in the olive orchard of Shahid Chamran University in 2016. Spray treatments were included T0 (Distilled water as control),T1 (1000 mg/l boric acid + 1000 mg/l potassium sulfate + 1000 mg/l zinc sulfate) and T2 (2000 mg/l boric acid+2000 mg/l potassium sulfate +2000 mg/l zinc sulfate ) which applied on olive cultivars in four time including a week before the full bloom (the second half of March), two weeks after the full bloom (the first half of April), at pit hardening (the first half of June of the month) and at the stage of oil synthesis and accumulation (first half of July). The research was performed in a factorial experiment based on a randomized complete block design with three replications thirty fruits from each tree were harvested, then the qualitative characteristics of fruit such as fruit fresh weight, pit fresh weight, fresh weight of the pulp, pulp/pit ratio, length and diameter of fruit and pit and also, to determine the amount of nutrients in the fruit and dry weight of the pulp, the samples were placed an oven for 48 hours at 80°C. After drying, the dry weight of the pulp was calculated, then the samples were completely powdered with the milling machine and the Kjedahl method was used Nitrogen, from a Flame Photo Meter to measure Potassium concentration and Atomic Absorption Spectrophotometry method was used for measuring Zinc and Boron of the available in fruit. Data analysis was performed using SAS software and mean of comparison was done by Duncan's multiple range test at 5% probability level.
Results and Discussion: The results indicated that the foliar spray had a significant effect on fruit fresh weight, fresh and dry weight of pulp, the ratio of Pulp/Pit weight, Oil content and amount of K, N, B and Zn of fruit, also fruit and pit dimension, but no significant difference in pit fresh weight were observed. Maximum oil content was 23.69% in Koroneiki cultivar sprayed with T1 treatment. Minimum oil content was 19.62% in Mission cultivar treated with distilled water. The highest and lowest rates in most of the studied traits were related to ‘Mission’ cultivar sprayed with T2 treatment and ‘Koroneiki’ cultivar treated with distilled water. The highest oil content was 23.69% in Koroneiki cultivar treated with T1 treatment. The highest amount of fresh weight of fruit (2.48 g) and pulp fresh weight (1.83 g) were obtained in ‘Mission’ cultivar treated with T2.It can be argued that food is responsible for activating cell division in addition to photosynthesis and organic matter transfer, Boron. Zinc and Potassium nutrients are treated trees, interfering with cell division and the synthesis of acid nucleic and increasing the formation and transfer of carbohydrates and by activating carbohydrate enzymes during fruit growth and development, improve the trait fruit.
Conclusions: The results of this study indicated that the spraying of the leaves of olive fruit trees, especially with T2 treatment (2000 mg / L of potassium sulfate, zinc sulfate and acid-boric), had the most positive effect on the increase of fruit properties compared to other treatments ,and increased the qualitative and quantitative traits of the fruit. Also, the results indicated that the cultivar had an influence on the characteristics of the fruit and by creating appropriate environmental conditions, especially the supply of nutrients during the growth stage of the fruit. Finally, the Mission cultivar has best response to T2 treatment by spraying of potassium, zinc and boron. There were significant differences between mission cultivar treated with T2 and other cultivars on fresh fruit weight, fresh and dry weight of pulp and fruit oil percentage, as well as the concentration of nutrients in fruit. The improvement in fruit characteristics should be due to the formation of more fruits, larger fruit and more fruit weight due to the role of Zinc and Boron in cell division and prolongation of the cell and increasing the volume of intercellular space in mesocarp cells. Conversely, Koroneiki cultivar showed the least reaction to spraying. Therefore, the characteristics of fruits are different in different cultivars, and the type of cultivars and soluble concentrations are effective on the quality of yield, which implies that leaf application can be used to increase the quality of olive fruit in hot areas.
Esmaeil Khaleghi; Noorollah Moallemi
Abstract
Introduction: Iran is located in arid and semi-arid regions, so limitation of precipitation and poor distribution of rainfall with prolonged periods of heat and drought have caused harsh conditions for establishing plants. In general, previous researches have shown that water deficit or drought stress ...
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Introduction: Iran is located in arid and semi-arid regions, so limitation of precipitation and poor distribution of rainfall with prolonged periods of heat and drought have caused harsh conditions for establishing plants. In general, previous researches have shown that water deficit or drought stress had destructive effects on morphological, physiological and biochemical parameters of plants. So that, researchers stated that the first reaction of plants to water stress was decline in growth. Growth parameters such as height, fresh and dry weight of root and stem and leaf area could decrease with increasing water stress. Therefore, use of methods for reducing water evaporation from soil, decreasing run-off and improving transport nutrients were considered in recent years. Superabsorbant polymers are one of the most important compounds in reducing negative effects of drought on plants.
Materials and Methods: This study was conducted to investigate the effect of five different levels of super AB A200 polymer (0, 1, 2, 3, 4 g/Kg of soil) and three levels of irrigation [100 as control, 65 and 30 percentage of plant evapotranspiration potential (ETcrop)] on morphological characteristics of two olive cultivars ‘Baghmaleki’ and ‘Dezphol’ as a factorial experiment based on randomized complete block design with three replications. In this experiment, ninety 18-month-old olive trees of ‘Baghmaleki’ and ‘Dezphol’ were kept for adaptation in greenhouse for one month.The plants were planted in ninety pots including 1/3 sand, 1/3 manure and 1/3 soil with superabsorbent polymer. Superabsorbent polymers (super AB A200) were prepared from Company Rahab Resin (Licensed by Iran Polymer and Petrochemical Institute). Then, the plants were irrigated with 100%, 65% and 30% ETcrop, every three days. Finally, morphological parameters such as root fresh weight, root dry weight, shoot fresh weight, shoot dry weight, height, leaf number, leaf Area and leaf area ratio were measured. Data analysis was performed using MSTATC software and mean comparison was done by Duncan's multiple range tests at 5 and 1% probability.
Results and Discussion: The results showed that interaction effect between irrigation and polymer affected shoot fresh weight, leaf fresh weight, shoot dry weight, leaf dry weight, height and leaf area ratio at p
seyyed mousa mousavi; mehrangiz chehrazi; Esmaeil Khaleghi
Abstract
Introduction: With regard to decrease of precipitation and poor distribution of rainfall during the dry phenomenon of urban, green spaces face problems. In fact, one of the most important environmental stress is drought stress at different stages of plant growth such as seed germination, seedling establishment ...
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Introduction: With regard to decrease of precipitation and poor distribution of rainfall during the dry phenomenon of urban, green spaces face problems. In fact, one of the most important environmental stress is drought stress at different stages of plant growth such as seed germination, seedling establishment and crop production. The effect of drought stress, plants photochemical activity ceased Calvin cycle enzymes and chlorophyll content also varies in the process of photosynthesis under drought stress. Under drought stress, reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), superoxide radicals (O2 • -) and hydroxide (OH •) increase their accumulation in cells that can lead to oxidative stress. To neutralize ROS, antioxidant enzymes systems in plant such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) are active. The response of antioxidants depends on the lack of water, the intensity of the stress and the type of plant species. Also, it is well known that photosynthetic systems in higher plants are most sensitive to drought stress. Indeed, drought is one of the factors affecting photosynthesis and chlorophyll content. Some of researchers reported that chlorophyll might estimate influence of environmental stress on growth because these parameters were closely correlated with the rate of carbon exchange. The aim of this study was an investigation of effect of water deficit different levels on antioxidant system and lipid peroxidation in two species of marigold. Therefore, an experiment was carried out as factorial in a randomized complete block design with three replication at Shahid Chamran University of Ahvaz in 2014 year.
Materials and methods: Experimental treatments were irrigation with three levels: 100% ETcrop (no stress), 75% ETcrop (moderate stress) and 50% ETcrop (severe stress) and two species of marigold (African and French). Catalase activity decreased absorption at a wavelength of 240 nm through catabolizing on the basis of H2O2 according to Beers and Sizer (1952). Peroxidase activity decreased absorption at a wavelength of 470 nm that was measured by using Hemeda and Kelin (1990). Ascorbate peroxidase enzyme extracted from leaf based on defects in the wavelength of 290 nm that was measured by Nakano and Asada (1987). The final product of membrane lipid peroxidation malondialdehyde concentration as the reaction thiobarbituric acid (TBA) was measured. Also, chlorophyll a, b and total chlorophyll were calculated by Arnon’s equations and chlorophyll content index (C.C.I) was measured by chlorophyll content meter (SPAD-502).
Results and discussion: Results of analysis of variance showed that irrigation treatment had significant effect on chlorophyll a, total chlorophyll (Chl a+b), chlorophyll content index and catalase peroxidase, ascorbate peroxidase enzymes activity and malondialdehyde while there was not significantly difference between two species of marigold on any of the measured biochemical characteristics. Also, results revealed that amount of leaf chlorophyll a and total chlorophyll (chl a+b) were reduced by increasing water deficit. In fact, amount of total chlorophyll, chlorophyll a, b and chlorophyll content index were higher in plants that were received 100% ETcrop than 75 and 50% ETcrop. ,The results of enzyme activity were similar to total chlorophyll and chlorophyll a and b. Amount of decreased chlorophyll a and total chlorophyll in plants were received 50% ETcrop were 24% and 47.46%, compared with 100% ETcrop, respectively.
Conclusion: Result showed that different levels of irrigation were significantly different at 5% level on catalase, peroxidase, ascorbate peroxidase enzymes activity and malondialdehyde concentration. Catalase, peroxidase, ascorbate peroxidase enzymes activity and malondialdehyde concentration were increased by reducing the amount of irrigation while there were no different between two species of marigold and interaction between species and irrigation was not effective on measured indexes.
seyyed mousa mousavi; mehrangiz chehrazi; Esmaeil Khaleghi
Abstract
Background and objectives: Water stress is one of the most important environmental stresses in agriculture and urban landscape management. Water stress has been defined as the induction of turgor pressure below the maximal potential pressure. Previous studieshave showed that drought had been negative ...
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Background and objectives: Water stress is one of the most important environmental stresses in agriculture and urban landscape management. Water stress has been defined as the induction of turgor pressure below the maximal potential pressure. Previous studieshave showed that drought had been negative effects on morphological, physiological and biochemical characteristics of plants. Changes in protein expression, accumulation, and synthesis have been observed in many plant species as a result of plant exposure to drought stress during growth plants. The maintenance of plant water potential during water deficit is essential for continued growth and can be achieved by osmotic adjustment mechanisms resulting from the accumulation of compatible solutes such as proline in the cytoplasm. Proline acts as a "compatible solute", i.e. one that can accumulate to high concentrations in the cell cytoplasm without interfering with cellular structure or metabolism. Proline has a protective action which prevents membrane damage and protein denaturation during water stress. Accumulation of sugars in different parts of plants is enhanced in response to the variety of environmental stresses. Marigold(Tagetesspp.) is a genus of annual or perennial, belonging to the Asteraceaefamily, that is used as a marginal flower in the landscape.Due to the fact that drought stress is one of the most important problems especially in the agricultural industry and also in the landscape, it is necessary to study the damaging effects of drought stress on plant characteristics. Therefore, the aim of this study was to investigate the effect of different levels of water stress on physiological and biochemical characteristics of two types of pot marigold.
Materials and Methods: A research was conducted in order to investigate the effect of different levels of water deficit (100 as control, 75 and 50 percent of potential evapotranspiration (ETcrop)) on trend changes of leaf proline, total soluble sugars, relative water content and soluble protein changes in two species of pot marigold (French and African) as a factorial experiment based on a randomized complete block design with three replications. In this experiment, two species of pot marigold seeds (African and French) were planted in the trays including cocopeat. Then seedlings were transplanted to pots with 19 × 16 cm dimensions. After transplanting, the seedlings were irrigated well for 3 weeks. Then plants were irrigated with 100%, 75% and 50% ETcrop. Parameters such as leaf proline and total carbohydrates content, leaf relative water content were measured three times at intervals of once every 21 days but the amount of soluble proteins was measured one time in 63 days after treatment. Data analysis was performed using MSTATC software and mean comparison was done by Duncan's multiple range test at 5% and 1% probability.
Results: The results showed that leaf proline and total soluble sugars increased with incrementin levels of water deficit and the trend changes of leaf traits were increased with the passing of time. So that, in 43 days after water stress treatment, leaf proline content had an increase of 3 or 4 times in 50% Etcrop irrigation treatment compared with the control and 75% Etcrop irrigation treatment, respectively. The highest levels of leaf proline (119.28 mg per gram of fresh weight) and total soluble sugars content (1.8 mg per gram of fresh weight) was related to 50% ETc treatment. The amount of leaf total soluble sugars was also higher in African species compared with French species. The results showed that the leaf soluble proteins and relative water content decreased with reducingirrigation, so that the lowest amount of relative water content (57.9%) and soluble protein (31.57mg per g fresh weight) were obtained in 50% ETc treatment.
Conclusion: When the plants were exposed to progressive drought stress, changes appeared earlier in relative water content, whereas later effects in the levels of free proline, total soluble sugar, total soluble protein. The results showed that irrigation had significant effects on all evaluated parameters such as leaf proline, total soluble sugers, RWC and soluble proteins. Our findings also showed that there was no significant difference between control treatment and 75% ETcrop treatment in the measured indices and it's importancfor optimal management of water in landscape couldbe considered. Finally, it can be expected that African species is better than French species for planting in landscape.
Z. Sedaghat Kish; noorolah moalemi; E. Khaleghi
Abstract
The aim of this study was evaluation of two different methods of auxin application for rhizogenesis in stem cutting of Duranta repens shrub with 2 indivijual experiments and in January and February 2008. Two factorial expriment based on RCBD was used and comparison of means was done with duncan multiple ...
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The aim of this study was evaluation of two different methods of auxin application for rhizogenesis in stem cutting of Duranta repens shrub with 2 indivijual experiments and in January and February 2008. Two factorial expriment based on RCBD was used and comparison of means was done with duncan multiple test at p
