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 ...
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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.
M. Sadat; H.R. Khazaie; A. Gazanchian
Abstract
Introduction: Significant impact of green space in the beautification of urban space and creating attractive face for cities has caused to per capita of urban green space be introduced as an important factor in urban development, especially in metropolitan areas. Meanwhile, the important role of covert ...
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Introduction: Significant impact of green space in the beautification of urban space and creating attractive face for cities has caused to per capita of urban green space be introduced as an important factor in urban development, especially in metropolitan areas. Meanwhile, the important role of covert plants, especially lawn grasses, in creating green spaces has caused to add quickly the area of these beautiful plants in the cities. On the other, existence of plants with high water requirements between the lawn 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. Sometimes from this point of view, they create limitations in terms of water supply. Hence, given the limited water resources in Mashhad city and the grass surface area in this city (which is more than 400ha), attempts at the removal of this limitation are necessary. Thus, this research was done with aim of evaluating the effect of mixing different amounts of MSW compost with soil on some root properties of Tall Fescue native grass, under moisture stress conditions.
Materials and Methods: The present study, was conducted in the form of two experiments, in research greenhouse of Ferdowsi University of Mashhad in 2016. The first experiment was conducted in a completely randomized design with four replications. The experimental treatments consisted of ten different levels of compost mixing with soil (10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 ton ha-1) and control treatment (agronomic soil without mixing compost). According to the results of the first experiment, three superior compost ingredients were selected and included in the second experiment. In the second experiment, these were considered, 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 non-stress, respectively as the second factor. They were compared in factorial pattern by a completely randomized design with four replications. So that, their effects should be investigated on some of the characteristics of the grass root of Tall fescue.
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 the 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, the interactions between different amounts of compost and drought stress levels were significant on all studied traits of grass root. So that, with increasing drought stress severity in different amounts of compost, characteristics of total length of root, volume of root and level of root would be increased and traits of drought weight of root and average thickness of root would be decreased. The results showed that in the treatment of 90 tons of compost per hectare, the plant has understood less level of the stress due to increased water holding capacity. Therefore, the lower part of the dry matter allocated to the development of roots.
Conclusion: By increasing severe of drought stress characteristics of total length of root, volume of root and level of root were increased and traits of drought weight of root and average thickness of root were decreased, it seems that tall fescue grass cleverly has tried to deal with for confronting drought stress with target of increase the amount of moisture available for itself. Also, based on the findings of this study, application of 90 tons of compost per hectare significantly improved root studied traits for tall fescue grass in drought stress conditions. Therefore, using this amount of compost for tall fescue grass in low water conditions and occurrence of moisture stresses is recommended.
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 ...
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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.
saleh Mohammadi; Hamireza khazaie; Ahmad Nezami; Yahya Tajvar
Abstract
Introduction: Among citrus producing provinces in the country, Mazandaran province ranks first with 1.88 million tons yields. Orange is one of the horticulture crop which is sensitive to low temperature stress. Low temperature stress is one of the abiotic stresses that its negative effects is the disruption ...
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Introduction: Among citrus producing provinces in the country, Mazandaran province ranks first with 1.88 million tons yields. Orange is one of the horticulture crop which is sensitive to low temperature stress. Low temperature stress is one of the abiotic stresses that its negative effects is the disruption of the electron transfer process through the thylacoid membrane. Actived oxygen radicals can be reacted with methyl unsaturated fatty acid groups and produce active fatty acid radicals. Very reactive formed radicals are capable of initiating lipid peroxidation chain reactions, which leads to the accumulation of free oxygen radicals that can lead to degradation of plant chlorophylls and membrane peroxidation and disruption of photosynthesis, accumulation of ROS, damage to cell membranes, destruction of plant pigments and nucleic acids. Plants can resist against low temperature stress by water saving and utilization of antioxidant system. The amount of free proline in many plants increases in response to environmental stresses such as cold and drought stress, and this physiological response can affect the resistance of the herbal substance under stress. Due to the diversity of citrus native genotypes in the country, the aim of this study was to determine the tolerance of native genotypes against low temperature stress in north of the country.
Materials and Methods: This experiment was conducted during the years 2015_2016 at the Citrus and Semi-Traditional Fruit Research Center in Ramsar with the aim of determining the low temperature tolerance of six native pseudo orange genotypes at 4 temperature levels (3, 0,- 3,- 6), compared to The test was carried out by Unsho and Sensitive Persian Lime (low temperature stress). Therefore, in this study, the vulnerability to low-stress conditions in controlled environmental conditions was compared with that of temperature treatments (3, 0, _3 and -6 degrees Celsius) in six genotypes of native pseudo-orange (number 1-6) sensitive cultivar (Persian lime) and resistant cultivars (Unsho) were investigated. This experiment was conducted as a factorial in a completely randomized design. The results of analysis of variance showed that temperature, genotype and interaction of these two treatments were significant in lipid peroxidation, proline, antioxidant capacity, ion leakage, hydroxylation, chlorophyll a and chlorophyll content. The temperature of the device began to decrease at a temperature of 6 ° C. The temperature of the device was 1 ° C / hour, after which the samples were kept at the specified temperatures for 3 hours and at the end of this period (3 Clock) sampling was performed to measure the traits. Accordingly, the leaf aquaculture was calculated by calculating the leaf area using a leaf surface gauge device. Ionic leakage measurements were also investigated using the method of the conversation and Meg Donald method. The presence of genotypes under cold stress led to an increase in malondialdehyde. In these conditions, due to increased oxidative activity, the accumulation of antioxidant compounds such as superoxide dismutase, glutathione peroxidase and catalase increased. The data obtained from this research were based on factorial experiment in a completely randomized design with three replications of analysis of variance and then averages were compared by Tukey test at 5% level using SAS software.
Results: Orange is a low temperature stress sensitive horticultural plant. Therefore, in this study, the vulnerability to low temperature stress in controlled environment (3, 0, 3- and -6 degrees Celsius) in six native poderotal genotypes (No.1-6) sensitive cultivars (Persian Liam) and resistant cultivars (Unsho) were studied. This experiment was conducted as a factorial in a completely randomized design. The results of analysis of variance showed that temperature, genotype and interaction of these two treatments were significant in lipid peroxidation, proline, antioxidant capacity, ion leakage, hydroxylation, chlorophyll a and chlorophyll content. Meanwhile, soluble carbohydrate was only affected by the simple factor of genotype. No effects on chlorophyll b and carotenoid pigments were significant. The highest incidences (99.33%), ion leakage (91.63%) and lipid peroxidation reaction (with a mean of 3.33 μg / kg of fresh leaf weight) were recorded in sensitive lambspeed control at 6 °C. In contrast, the highest amount of proline (32.01 mg / g leaf weight) and antioxidant capacity (73.36%) was recorded in the control group at 3 °C. Among the native pseudo-orange genotypes, in this study, different reactions were also observed under low-temperature stress conditions. Accordingly, after the control of the bird, the native pseudo-orange genotype number one was better than the one under temperature decrease. However, in most of the studied orange genotypes, in most of the destructive traits, the native pseudo-orange genotype number 6 was in the same statistical position or close to the sensitive Peninsula. The presence of genotypes under cold stress led to an increase in malondialdehyde. In these conditions, due to increased oxidative activity, the accumulation of antioxidant compounds such as superoxide dismutase, glutathione peroxidase and catalase increased.
mahdi yaghoobi; mahdi parsa; Ali Gazanchian; hamidreza khazaie
Abstract
Introduction: Lack of water resources is one of the most problems ofincreasing urban green spaces. Over the last threedecades, turfgrass and lawn researches have put significant effort into developing and evaluating turf species that have good drought resistance. As water conservation becomes an important ...
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Introduction: Lack of water resources is one of the most problems ofincreasing urban green spaces. Over the last threedecades, turfgrass and lawn researches have put significant effort into developing and evaluating turf species that have good drought resistance. As water conservation becomes an important issue, considerable interest is increasing in identifying grasses that require less water. Plants with good drought resistance are those that are able to survive stress by means of drought avoidance, drought tolerance at leaf water potentials, or both. The efficient use of water is made possible by understanding the effects of irrigation water on crop development and yield. Drought affects the visual quality, growth rate and evapotranspiration. Researchers reported that turfgrass subjected to drought conditions for short periods could sustain a fairly good appearance by irrigation about half of its consumptive use whenever soil moisture level falls to near permanent wilting point. Drought stress caused decrease in RWC and visual quality of many grass cultivars. In drought conditions resistance grass showed increase in proline content on their leaves. Therefore the use of native grasses with high-strength instead of grass imported with low-resistance is one way to increase green space and reduce costs. The purpose of this study was comparednative grasses with commercial grass cultivars.
Materials and Methods: This study was to evaluate the yield and resistance of native grasses to drought stress in 2014. This experiment was conducted in Khorasan Agricultural Research Center. NativeAgropyron grass species includedAgropyronelangatum, A. desertrum, A. cristatum and commercial cultivarwassuper sport and third level of stress, including severe stress (45% FC), moderate stress (65% FC) and control (85% field capacity) were experimental treatments. Plants were cultured in PVC containers measuring 9 cm in diameter and 60 cm deep under greenhouse condition. Soil was mixture of 70% loam soil, 20% pit mass and 10% sand. Greenhouse air temperature was maintained between 22 and 28 centigrade degree. All plants were maintained under well watered conditions for 45 days before drought stress. This experiment was designed in factorial experiment based on completely random with fourreplicates. After the stress treatment parameters such as length and width of leaves, chlorophyll a, chlorophyll b and total chlorophyll content, visual quality, electrolyte leakage, RWC and proline content of leaves were measured. Length and width of leaves were measured with ruler. Proline content, RWC percent, chlorophyll a, chlorophyll b and total chlorophyll content of leaf, visual quality and leaf electrolyte leakage weremeasured with standard protocols. Analysis of the data by statistical software JMP 8 and graphs with Excel 2010 was drawn.
Results and Discussion: Result of the experiment showed that those native species have different response to soil moisture stress conditions. The highest and lowest lengths of leaf were observed under45% field capacity in A. elangatum and super sport grass, respectively. The results showed that width of leaves of A. elangatum increase and then decrease in super sport. Under drought stress conditions A. desertrum has best visual quality with 6.07 score. Highest chlorophyll a and total chlorophyll were observed in A. elangatum. The lowest electrolyte leakage under drought stress was obtained from A. elangatum with 17.91 percent. RWC content in the native A. elangatum increased to 82.12 compared with super sport (control). A. elangatum under drought stress showed highest proline content and commercial cultivar (super sport) indicated lowest proline content at 45% field capacity irrigation. Selahvarzi and et al. (2009) found that visual quality of tall fescue decrease in drought stress. In drought stress, RWC percent decrease in grass species. Proline content was increasedupondrought stress inLoliumperenecool season grass. Many studies on native cultivar indicated that native turfgrass cultivar have more resistance to drought stress compared with exotic turfgrass cultivars.
Conclusions: According to the results, we said native grass species under drought stress conditions have better quality compared with imported grass cultivar such as Super sport. Visual quality in native grass was suitable for use in urban landscape, that visual quality show little change in drought stress and leaves were fresh in this conditions. The best visual quality of two native species A. elongatum and A. desertrum was observed under 65% field capacity. Nativegrass cultivars were more resistance than imported grass cultivars. This study showed that native grass such asA. elongatum and A. desertrumhas low cost to use and these turfgrass need to lower water irrigation than commercial grass Super sport. Then two species can be introduced as low-input cultivars.
ramin mahdavi; madhi parsa; ali gazanchian; hamidreza khazaie
Abstract
Introduction: Over the last three decades, turfgrass breeders have put significant effort into breeding and developing turf species that have good drought resistance. As water conservation becomes an important issue, an interest is increasing in identifying grasses that require less water. Lack of water ...
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Introduction: Over the last three decades, turfgrass breeders have put significant effort into breeding and developing turf species that have good drought resistance. As water conservation becomes an important issue, an interest is increasing in identifying grasses that require less water. Lack of water resources is most problems to increasing urban green spaces. Plants with good drought resistance are those that are able to survive stress by means of drought avoidance, drought tolerance at leaf water potentials, or both. The efficient use of water is made possible by understanding the effects of soil moisture water on crop development and yield. Drought affects the visual quality, growth rate and evapotranspiration. Researchers reported that turfgrass subjected to drought conditions for short periods could sustain a fairly good appearance by soil moisture about half of its consumptive use whenever soil moisture level falls to near permanent wilting point. Drought stress caused decrease in RWC and visual quality of many grass cultivars. In drought conditions resistance grass showed increase in proline content on their leaves. Therefore the use of native grasses with high-strength instead of imported grass with low-resistance is one way to increase landscape areas and reduce costs. The purpose of this study was to be compared native grasses with commercial grass cultivar “Super sport”.
Materials and Methods: The objective of this study was to evaluate the effect of soil moisture stress levels included 85% (control), 65% and 45% of field capacity on native species Brumos tomentellus, Festuca rubra and F. arundinacea and commercial cultivars Super sport (control) under greenhouse conditions. Plants were cultured in PVC containers measuring 9 cm in diameter and 60 cm deep. Soil was mixture of 70% loam soil, 20% pit mass and 10% sand. Greenhouse air temperature was maintained between 22 and 28 centigrade degree. All plants were maintained under well watered conditions for 45 day before drought stress. This experiment was conducted as factorial experiment based on completely random design with four replications. Measured parameters were length and width of leaves, chlorophyll a, chlorophyll b and total chlorophyll content, visual quality, electrolyte leakage, RWC and proline content of leaves. Length and width of leaves measured with ruler. Proline content, RWC percent, chlorophyll a, chlorophyll b and total chlorophyll content of leaf, visual quality and leaf electrolyte leakage was measured with standard protocols. Analysis of the data by statistical software JMP 8 and graphs with Excel 2010 was drawn.
Results and Discussion: Result of the experiment showed those native species have different response to soil moisture stress conditions. The highest and lowest length of leaves were observed in 65% field capacity in F. arundinacea and super sport grass, respectively. The results showed that width of leaves of B. tomentellus increased and decreased in super sport. Under soil moisture stress conditions, F. arundinacea has best visual quality with 7.66 score. Highest chlorophyll a and total chlorophyll were observed in tall fescue grass. The lowest electrolyte leakage under drought stress was obtained from F. rubra with 25.66 percent. RWC content in the native F. arundinacea increased to 77.80 compared with super sport (control). B. tomentellus under soil moisture stress showed the highest proline content and commercial cultivar (super sport) indicate lowest proline content at 45% field capacity. Selahvarzi and et al. (2009) found that visual quality of tall fescue decrease in drought stress. In drought stress RWC percent decrease in grass species. Proline content was increased in drought stress at Lolium perene cool season grass. Much studies on native cultivar indicated that native turfgrass cultivar have more resistance to drought stress compared with exotic turfgrass cultivars.
Conclusions: According to the results, we said native grass species under drought stress conditions have better quality compared with imported grass cultivar Super sport. Visual quality in native grass were suitable for use in urban landscape, that visual quality showed little change in soil moisture stress and leaves were fresh in this conditions. Native grass cultivars were more resistance than imported grass cultivar. This study showed that native grass such as F. arundinacea and F. rubra has low cost to use and these turfgrass need to lower water soil moisture than commercial grass Super sport.
Golnar GhazianTafrishi; hossein arouiee; Majid Azizi; Hamidreza Khazaie; Saeedreza Vessal
Abstract
Introduction: Plants native to tropical and subtropical climates which grown in the temperate climate zone, suffer chilling injury when exposed to non-freezing temperatures for a certain period of time. The optimum growth temperature for cucumber (a tropical plant) is 20 to 25°C. Cucumber is sensitive ...
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Introduction: Plants native to tropical and subtropical climates which grown in the temperate climate zone, suffer chilling injury when exposed to non-freezing temperatures for a certain period of time. The optimum growth temperature for cucumber (a tropical plant) is 20 to 25°C. Cucumber is sensitive to temperatures lower than 10 °C. Cucumber area of production exposes to late spring and early autumn cold weather in Khorasan-e-Razavai, Iran. Studies showed that chilling leads to an alteration in fatty acid composition of membrane lipids and its permeability, changes in photosynthetic pigments content and decrease in photosynthesis. Many researchers pointed to a possible role of polyamine compounds in plant defense against environmental stresses. Exog enous application Spd could prevent the electrolyte and amino acid leakage or recovering the plasma membrane damage in rice and cucumber in response to salinity, chilling and water stressed conditions.
Materials and methods: A factorial experiment, based on completely randomized design was conducted to investigate the effect of short-term chilling on cucumber plantlets which was earlier treated with spermidine. Factors were included two levels of temperature (6 and 12°C) and four levels of spermidine (0, 0.25, 0.5 and .0.75 mg/L). The studied cultivar was ‘Super-Dominus’. In order to determine the extent of chilling injury, plants of each treatment were rated based on visual symptoms. By assigning values of 1, 2, 3, 4, and 5 while 1: no visible symptoms 2:5% of leaf area necrotic, 3: 5-25% of leaf area necrotic, 4: 26-50% of leaf area necrotic but plant still alive, 5: lost, entire plant necrotic and collapsed. Measured traits were root and shoot length, root and shoot dry weight, root and leaf electrical leakage, and leaf chlorophyll content.
Results and discussion: Plants which exposed to low temperature showed chilling injury symptoms (5-25% leaf area necrotic). The symptoms reduced (less than 5% leaf area necrotic) by using 0.25 and 0.5 mg/L spermidine. The symptoms enhanced by 50% by applying 0.75 mg/L spermidine at 6°C. Analysis of variance showed that there was significant difference between temperature levels, spermidine levels and interaction between them in respect to root length, shoot length, shoot dry weight and root and leaf electrical leakage. Root dry weight, root to shoot ratio and chlorophyll content just affected by temperature and spermidines levels but not by interaction between them. Root and shoot length and dry weight decreased by low temperature. At cold stress condition growth decreased due to a reduction in photosynthesis and carbohydrate metabolism .Root and shoot length decreased more than 79% at 6°C compare with 12°. Root to shoot ratio increased at cold condition which was the result of lower root weight loss in response to cold temperature compared with shoot weight losses. Electrical leakage (EL) enhanced in leaf and root cells at chilling temperature, but the enhancement was significantly more at root cells. Electrical leakage enhanced more than 52% in root cells at 6°C compared with 35% in leaf cells. EL suppressed, using 0.25 and 0.5 mg/L spermidine while an increase observed in El at 0.75 mg/L spermidine. The lowest EL percentage observed for leaf samples treated with 0.25 and 0.5 mg/L spermidine at 12°C. The highest EL percentage belonged to root samples treated with 0.75 mg/L Spd at 6°C .Chlorophyll content (ChlC) decreased at cold condition. ChlC was 52% at12°C compared with 37% at 6°C. High significant correlation observed between chlorophyll content and shoot dry matter (r2= 0.96**). Root and shoot length and dry weight and leaf chlorophyll content enhanced using 0.25 and 0.5 mg/L spermidine at both chilling and control temperatures. A decrease observed in measured traits applying 0.75mg/L spermidine. There was no significant difference between 0.25 and 0.5 mg/L spermidine levels in respect of measured traits expect for shoot dry weight. Spermidine enhances chilling tolerance in cucumber by prohibiting the activity of NADPH oxidase. The capacity of PAs to enhance the tolerance of cucumber to chilling injury is attributed to the scavenging of H2O2 production under chilling condition.
Conclusion: Results showed that root and shoot length and weight, root and leaf electrical leakage and chlorophyll content of leaf adversely affected by chilling stress. Using 0.25 mg/L spermidine modulates plant responses to chilling stress. There was no significant difference between 0.25 and 0.5 mg/L spermidine in respect of measured traits. But all measured traits adversely affected using 0.75 mg/L spermidine at both 6 and 12°C.
saeed khaninejad; Hamidreza Khazaie; Jafar Nabati; Mohammad Kafi
Abstract
Potato is one of the most productive crops in agriculture and is a valuable food source in developing countries. Mycorrhizal fungi involve a symbiosis with most of crop roots and leads to improve the crops growth and yield. In order to investigate the effect of mycorrhiza fungi species on yield of potato ...
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Potato is one of the most productive crops in agriculture and is a valuable food source in developing countries. Mycorrhizal fungi involve a symbiosis with most of crop roots and leads to improve the crops growth and yield. In order to investigate the effect of mycorrhiza fungi species on yield of potato cultivars a factorial experiment was arranged in a randomized complete block design with eight treatments (seven mycorrhiza fungi species and control treatment) on two potato cultivars, Agria and Fontane, in three repetitions. Results show that there is no significant difference in tuber yield and shoot P content in Agria and Fontane, but leaf area and shoot dry weight and total tubers weight in Fontane were higher than Agria. Control treatment and A. longula had the least and G. mosseae، G.intraradices and G. versiform had the highest tuber weights. Among fungi G. mosseae produced the highest tuber yield in both cutivars. Inoculation of root medium with G. versiform produced the highest average tubers weight compared to other treatments. Phosphorus content of treated plants with mycorrhiza was higher than control.
A. Eskandari; H.R. Khazaie; Ahmad Nezami; Mohammad Kafi; A. Majdabadi
Abstract
Abstract
In order to Study the effects of irrigation regimes on physiological traits, yield and water use efficiency of potato (Solanum tuberosum L.) in Mashhad weather condition, an experiment was conducted in 2009 at research field of the College of Agriculture, Ferdowsi University of Mashhad, using ...
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Abstract
In order to Study the effects of irrigation regimes on physiological traits, yield and water use efficiency of potato (Solanum tuberosum L.) in Mashhad weather condition, an experiment was conducted in 2009 at research field of the College of Agriculture, Ferdowsi University of Mashhad, using factorial experiment based on randomized complete blocks design with 3 replications. Experimental factors were 3 irrigation regimes including: I1: provided with 100% of water requirement of potato, I2: provided with 70% of water requirement of potato applied before tuber initiation and I3: provided with 70% of water requirement applied at all growth period of potato as first factors and 3 potato cultivars (Agria, Almera and Sinora) as second factors. The results indicated that about physiological traits when provided with 100% water requirement of potato the highest of relative water content, quantum efficiency of photosystem II, leaf area index and canopy height related to this irrigation regime. Even though with reduce in irrigation volume because of decreasing in LAI, the SPAD index in some cases was higher. Also in all irrigation regimes total tuber yield of Agria cultivar was better than to others. Considering to the calculation of water use efficiency with 30% decreasing in irrigation volume before tuber initiation, Agria had the highest WUE in provided with 70% water requirement. Finally, it seems that with decreasing in irrigation volume at Mashhad weather condition, Agria had the best growth and more acceptable yield compared to other genotypes.
Keywords: Potato, Irrigation regimes, Cultivar, Water Use Efficiency
R. Sasani; H. R. Khazaei; Ahmad Nezami
Abstract
Abstract
Dormancy in potato minituber buds is one of the limiting factors on planting them after harvesting. This study was undertaken in a completely randomized Nested with arrengment three replications to examine the effective hormonal and temperature treatments on rapid breaking of minitubers dormancy ...
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Abstract
Dormancy in potato minituber buds is one of the limiting factors on planting them after harvesting. This study was undertaken in a completely randomized Nested with arrengment three replications to examine the effective hormonal and temperature treatments on rapid breaking of minitubers dormancy at 2008. Treatments included gibberellic acid (2 and 5 mg/l), benzyl adenine (5 and 10 mg/l), zeatine (1.5 and 3 mg/l) and temperature (5, 10 and 15oC). Results showed that germination rate and percentage, length of sprouts, number of active sprouts, tuber weight were affected by hormonal and temperature. Germination rate and percentage were not significantly different amoung hormones under temperature 15oc but lowest was respectively 14.4 and 11 for control. Most effect on length of sprouts was resulted in 5 mg/l gibberellic acid. Temperature 10oc had most affect on number of active sprouts. Under low temperature effect of hormones on studied was not significant. Loss of Tuber weight under low temperature (5oc) and high temperature (15oc) was high and low respectively.
Key words: Potato, Dormancy of minituber, Dormancy breaking
Hamidreza Khazaie; Mohammad javad Arshadi
Abstract
Abstract
In order to investigate the effects of nitrogen fertilizer levels on THE yield and quality of potato, (Solanum tuberosum L.) a field experiment was conducted based on randomized complete blocks design with 3 replications in the Research Field of the College of Agriculture, Ferdowsi University ...
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Abstract
In order to investigate the effects of nitrogen fertilizer levels on THE yield and quality of potato, (Solanum tuberosum L.) a field experiment was conducted based on randomized complete blocks design with 3 replications in the Research Field of the College of Agriculture, Ferdowsi University of Mashhad. Nitrogen topdress fertilizer was applied in two levels of 100 and 150 kgN.ha-1 and in two nitrogen indexes of 90 and 95 percent. In this research, chlorophyll meter was used to identify the required proper time of potato crop to nitrogen fertilizer. The results indicated that 95 percent OF nitrogen index versus 90 percent OF nitrogen index has a better efficiency in THE AUGMENTATION of potato crop yield. But in 95 percent index, nitrogen fertilizer levels of 100 and 150 kgN.ha-1 did not SHOW significant difference in tuber yield. Nitrogen indexes and nitrogen fertilizer levels did not have A significant effect on the tuber dry matter percent. 95 percent nitrogen index and nitrogen fertilizer levels caused A significant DECREASE on the tuber specific gravity. 90 percent nitrogen index and nitrogen fertilizer level of 100 kgN.ha-1 caused A significant DECREASE on the tuber of protein. The percentage of medium and large tuber increased when the nitrogen fertilizer was increased. In general it seems that THE nitrogen fertilizer application, in addition to producing desirable yield of tuber, leads to make desirable quality of tuber and economy in nitrogen fertilizers application by using chlorophyll meter.
Keywords : nitrogen fertilizer , yield and quality of potato , chlorophyll meter , nitrogen index
