Ornamental plants
T. Oraee; M. Shoor; A. Tehranifar; S.H. Nemati; A. Oraee
Abstract
Introduction Climate change predictions indicate that drought and extreme heatwaves will become more frequent and extreme in many regions. Drought is the main abiotic stress that severely reduces plant yield across the globe. Thus, this may have negative consequences for the agricultural soils, ...
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Introduction Climate change predictions indicate that drought and extreme heatwaves will become more frequent and extreme in many regions. Drought is the main abiotic stress that severely reduces plant yield across the globe. Thus, this may have negative consequences for the agricultural soils, as it limits the availability of water and nutrients to soil microorganisms and plants that develop on these soils. To cope with this situation, the use of organic amendments is the best option. Recent studies have shown that the application of organic fertilizers can affect soil moisture and thus, mitigate the negative effect of climate change on that parameter. Organic amendments increase soil organic matter content thus improving soil physical, chemical, and biological properties, and therefore, can confer drought resistance to soils. The application of organic residues has been presented as a great strategy against soil degradation in semiarid environments. However, the interactions between organic amendments and drought in hollyhock plants are not fully known. Here, we evaluate whether the organic amendment influences the physiological traits of hollyhocks and soil properties under drought conditions. Materials and Methods The experiment was conducted in the research field at Ferdowsi University of Mashhad, Iran. The experiment consisted of three factors (cultivars, organic amendments, and drought) with organic amendments and drought having four and three levels, respectively. Drought treatments were controlled by a TDR at 80, 60, and 40% FC. The three sources of organic amendments were used cow manure, rice hull and wheat straw. Seeds were planted in cocopeat, perlite, and peat mixture trays in the greenhouse with an average temperature of 20 °C and under a photoperiod of 14 hours of light and 10 hours of darkness with a light intensity of 400 μmol-1 m2. In the 5-6 leaf stage, seedlings were transferred in pots (18 cm high and 8 cm in diameter) containing field soil. The plants were transferred to the field with four different substrates (field soil, field soil + manure, field soil + rice hull, and field soil + wheat straw) and were exposed to drought stress for one month during the flowering stage. This analysis examined both the physical and chemical properties of the soil, including changes in the macroelements nitrogen, phosphorus, and potassium. Results and Discussion Soil nitrogen changes were significantly affected by the interactions of ecotype with drought, ecotype with the medium, and drought stress with medium. The highest nitrogen changes were recorded in Mashhad ecotype under 80% FC. Nitrogen content in amended soil had an increasing trend during the experiment, but the amount of nitrogen had a decreasing trend in soil. In all media under stress, the amount of soil phosphorus was increased and the highest amount of phosphorus was observed in soil + manure at all irrigation regimes. The highest amount of potassium in both ecotypes was observed in soil + manure. The amount of potassium in amended soils under stress significantly increased, but in all organic amendments with increasing drought stress from 80 to 40% FC, the potassium content decreased. In both ecotypes, soil salinity was increased in all culture media. Han et al. (2016) stated that the amount of nitrogen, phosphorus, and potassium in the amended soil was higher than the substrates containing chemical fertilizer. The medium EC was alkaline at the end of the experiment and the salinity of the culture medium increased compared to the control. This study revealed a negative correlation between electrolyte leakage and dry weight in hollyhock plants. Furthermore, all measured physiological and growth parameters were significantly affected by the treatments. Notably, the Mashhad ecotype grown in soil supplemented with animal manure at 80% field capacity (FC) exhibited the highest levels of physiological traits (SPAD and relative water content) and growth index (dry weight).The application of manure + soil by providing macro elements reduces the negative effects of drought stress. Conclusion The type of crops grown in arid and semi-arid regions should be reconsidered. Also, some plants with high water requirements should be replaced with plants with low and unexpected water requirements. Because hollyhocks are low-expected plants that grow well in drought areas, so they can be considered as suitable species for cultivation in low-input systems and can tolerate drought situations by 40% FC in amended soil.
Ornamental plants
Ali Sahari Moghaddam; Behzad Kaviani; Ali Mohammadi Torkashvand; Vahid Abdossi; AliReza Eslami
Abstract
IntroductionYew or English yew (Taxus baccata L.) from the family of Taxaceae is an ornamental shrub that is used in various industries. Root induction and formation process at the base of stem cuttings of yew is slow. This species is in danger of extinction. Stimulation of rooting in cuttings causes ...
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IntroductionYew or English yew (Taxus baccata L.) from the family of Taxaceae is an ornamental shrub that is used in various industries. Root induction and formation process at the base of stem cuttings of yew is slow. This species is in danger of extinction. Stimulation of rooting in cuttings causes the plant to grow faster. Polyamines are a group of plant growth regulators that play a variety of roles, including cellular differentiation and development and stimulation of adventitious root production. Some yew habitats have been destroyed because of neglect, destruction, livestock and ineffective exploitation. The yew is propagated by seeds or through cutting and grafting. Propagation of yew through seed is difficult and obtained plants show non-uniformity. Therefore, vegetative propagation is used to produce plants similar to the mother plant. The proliferation of the plant through leafy stem cutting is one of the most famous and the best propagation methods due to the preservation of the genetic structure and uniformity. Increasing the rooting capacity of trees and shrub cuttings is being carried out with a variety of plant growth regulators around the world. Putrescine has shown a better response in compare with other polyamines. The stimulation effect of exogenous application of polyamines, especially putrescine, was shown on the rooting of several plants’ cutting. Literature evaluation showed that there is not any study on the effect of polyamines on the rooting of the yew stem cuttings. Therefore, the aim of this research was to improve the rooting conditions of difficult-to-root cuttings with different concentrations of putrescine (a type of polyamine). Materials and MethodsIn order to investigate the effect of different concentrations of putrescine, an experiment was performed based on a completely randomized block design with 4 replications. Treatments included 0 (as a control), 500, 1000, 2000, 3000, 4000 and 5000 mg.l–1 of putrescine concentrations. In October, 25 cm of the end of the shoot of 5-years-old mother plants were cut and used as hardwood cuttings. The cuttings diameter was 2.5-3 mm. The lower ends of the shoot cuttings were kept at different concentrations of putrescine for 10 seconds and then placed in the cultivation bed. In this study, root percentage, number of roots, root length, stem length, shoot number, leaf number and survival percentage of cuttings were measured. Cuttings cultivation bed was perlite, cocopeat and peat moss. To prevent possible contamination, the bottom of the cuttings were immersed in a 2/1000 fungicide solution of Berdofix a week befor cutting preparation. Results and DiscussionThe results of analysis of variance showed that different concentrations of putrescine on all traits were significant at 1% probability levels. The results of mean comparison showed that the largest number of roots (6.50 per plantlet) and the highest root length (7.70 cm per plantlet) were observed in cuttings treated with 500 mg.l–1 putrescine. The highest number of shoots (5.50 per plantlet) and the highest rooting percentage (97.50) were obtained in cuttings treated with 2000 mg.l–1 of putrecine. The maximum number of leaves (41.25 per plantlet) was counted in cuttings treated with 3000 mg.l–1 of putrescine. Yew can be propagated successfully by stem cuttings. Natural conditions propagation and in vitro propagation beside cryopreservation are effective approaches to conserve plants particularly those putted in the red list. Plant growth regulators have an effective role in increasing the rooting of difficult-to-root cuttings of trees and shrubs. The exogenous use of polyamines as a new group of hormones stimulated root production in some cuttings. Peach × almond hybrid cuttings treated with 2 mM putrescine for 5 min showed the highest rooting percentage, root number and root length with the best quality. Putrescine is capable to influences on other plant growth regulators and has less toxicity than most of them. Polyamines stimulate cellular division in dissection place cells of cuttings such as cambium and phloem. The exogenous application of these compounds, especially putrescine during the root formation phase resulted in an increase in endogenous putrescine, endogenous auxin and peroxidase enzyme activity. In the cutting of the leafy stem of Corylus avellana L., the use of putrescine stimulated rooting. The study, like the present study, confirmed that putrescine can be useful for increasing rooting percentage and root quality. Putrescine had an effective role in the rooting of the stem cuttings. The present study revealed that the lowest root number was counted in cuttings that were not treated by putrescine (control). Polyamines (spermine, spermidine and putrescine) increased rooting percentage and root growth by stimulating root cell division (increased mitotic index of tip root cells) in regenerated pine (Pinus virginiana Mill.) seedlings. Polyamine biosynthesis and antioxidant enzymes activity were increased during root induction and formation. The exogenous application of spermidine in the apple (Malus prunifolia) stem cutting stimulated rooting by changing the concentration of some hormones. Spermidine regulated the expression of genes involved in the production of auxins. The study aimed to investigate the cellular-molecular effect of polyamines on the structure and development of roots in Arabidopsis showed that these organic compounds adjusted the size of the root meristematic zone during the effect on both symptomatic accumulations of hormones and reactive oxygen species (ROS). The same and different results are presented with the present findings by some other researchers. The main cause of these different results is the difference in the amount and balance of endogenous hormones, including polyamines in different species. Plant genotype, type of cuttings, cutting age, environmental factors, nutritional status especially type and amount of carbohydrates in the plant, the transfer rate of these carbohydrates from leaves to roots, the presence and the amount of phenolic compounds, nitrogen compounds, phonological stages and cutting season also play an effective role in these differences.
Ornamental plants
Meisam Mohammadi; Fatemeh Khosravifar; Negin Siahi
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 ...
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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 Methods This research was carried out in 2022 in pots in the research greenhouse of Ilam University as a factorial based on a completely random design with three replications. Experimental treatments included three salinity levels with sodium chloride salt (without salinity, 50 and 100 mM sodium chloride) and three levels of glycine betaine foliar spraying (0, 5 and 10 mM). Glycine betaine application was performed after mowing twice with a distance of 48h from each other, and then salinity with sodium chloride salts was applied. 4 weeks after application of salinity stress, some morphological and biochemical characteristics of plants were measured. The results were analysed using SAS software (v.9.2), and Tukey's test was used to compare the means at the 5% probability level. Results and DiscussionThe 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.
Ornamental plants
N. Zomorrodi; M. Shoor; A. Tehrani far; M. Goldani
Abstract
Introduction Since the beginning of the industrial revolution, the indiscriminate consumption of fossil fuels has led to a dramatic increase in the concentration of atmospheric carbon dioxide. Over the past few decades, the concentration of atmospheric carbon dioxide has increased from 280 to 370 ...
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Introduction Since the beginning of the industrial revolution, the indiscriminate consumption of fossil fuels has led to a dramatic increase in the concentration of atmospheric carbon dioxide. Over the past few decades, the concentration of atmospheric carbon dioxide has increased from 280 to 370 ppm and is expected to increase by about 1.8 ppm each year. Carbon dioxide, such as light, appropriate temperature, water and nutrients, is one of the essential nutrients needed by plants, which is currently less than required by plants. In general, plants need to absorb water from the soil and carbon dioxide from the atmosphere and use it in photosynthesis, which This is done by absorbing carbon dioxide through the through the pores. In general, stomatal properties have a major influence on the response of plants to carbon dioxide treatment. Leaf morphology, including stomatal density, may have a significant effect on the response of plants to carbon dioxide. There seems to be a great deal of variation among plant species in terms of how stomata density changes with increasing CO2 concentration. The opening and closing of the stomata through carbon dioxide absorption, regulates the amount of water wasted when adverse environmental conditions. In fact, increasing carbon dioxide in plants reduces stomatal conductance and transpiration, increases water use efficiency, photosynthesis rate and higher light utilization efficiency. Materials and Methods This study was conducted as a split plot experiment based on a completely randomized design with three replications in the research greenhouse of Ferdowsi University of Mashhad. Treatments included three concentrations of carbon dioxide (380 ppm as control, 700 and 1050 ppm) as the main plot and two species of ornamental ficus (Benjamin and Elastic) as sub plots. At first, cuttings were rooted in boxes containing washed sand infused with carbendazim for 8 weeks. After rooting, the cuttings were transferred to culture media containing appropriate soil mixture and exposed to different concentrations of carbon dioxide for 16 weeks. Were affected. Mean daily temperature of 25 and mean night temperature of 18 °C and 65% humidity were considered equal for all treatments. Then, after the treatments, Stomatal traits were measured. Results and Conclusion The results showed that high concentrations of carbon dioxide can affect the anatomical traits of Ficus ornamental species. In this study, the results obtained from the analysis of variance of the studied traits showed that the effect of different concentrations of carbon dioxide was not significant only for the stomatal index, but for other traits studied in this study. The main effect of carbon dioxide concentration was significant at 1% probability level.The results showed that the traits of stomata diameter in plant species and different concentrations of carbon dioxide were significant at 5 and 1% probability levels, respectively. Also with increasing the concentration of carbon dioxide the diameter of the stomatal decreased so that the highest stomatal diameter was related to the concentration of 380 ppm and the lowest to the concentration of 1050 ppm. In fact, increasing the concentration of carbon dioxide from the level of 380 to 1050 ppm led to a decrease of 19.91 percent in the diameter of the stomatal. Increasing the concentration of carbon dioxide in the environment of plants, initially increases the slope of the concentration of carbon dioxide between the surrounding air and the chamber under their stomata, and then more carbon dioxide through the pores leads to a decrease in the slope due to the abundance of carbon dioxide in the chamber below the stomata, This action reduces the diameter of the stomatal. As the concentration of carbon dioxide increased the stomatal cell density and stomatal area. Among the high concentrations of carbon dioxide the concentration of 700 ppm affected most of the traits, including stomatal diameter, stomatal area, epidermal cell density, stomach length and stomach width. though there was no significant difference between high concentrations of carbon dioxide (700 and 1050 ppm). According to the results of this study, it seems that anatomical traits are influenced by environmental factors and are not recognized as a hereditary factor. Among the species, the elastica species showed the most reaction to carbon dioxideal. Conclusion In general, clarifying the stomatal response to carbon dioxide concentration is important for understanding the stomatal physiology and gas exchange between vegetation and the In general, stomatal properties have a major influence on the response of plants to carbon dioxide treatment. Carbon dioxide at appropriate concentrations can increase growth and also affect the stomach properties to allow the plant to adapt to environmental conditions.
Ornamental plants
R. AbaszadehFaruji; M. Shoor; A. Tehranifar; B. Abedy
Abstract
Introduction Unbalanced and frequent use of chemical fertilizers and pesticides results in the degradation of soil physicochemical properties, loss of soil-born organisms, reduction of quality of produced crops and reduction of yield plant. Nowadays, due to environmental considerations of chemical ...
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Introduction Unbalanced and frequent use of chemical fertilizers and pesticides results in the degradation of soil physicochemical properties, loss of soil-born organisms, reduction of quality of produced crops and reduction of yield plant. Nowadays, due to environmental considerations of chemical fertilizers, use of organic acids for quantitative and qualitative improvement of crops has been increased. Humic materials are natural organic compounds that contain 50 to 90% of organic matters of peat, wood coal and rotten material, as well as non-living organic matters of aquatic and terrestrial ecosystems. Humic compounds indirectly increase soil fertility by providing micro- and macro-elements for root, improving soil structure, increasing medium permeability to water and air, increasing soil microbial population and beneficial microorganisms, increasing cation exchange capacity and the ability to buffer pH of medium or nutrient solution, and providing some special substances for plant roots such as nucleic acids and acetamides.Materials and Methods In order to investigate the influence of humic and fulvic acids on some growth characteristics in ornamental plant of Scindapsus spp., an experiment was conducted based on a completely randomized design with three replications at greenhouse in Ferdowsi University of Mashhad during 2014-2015. The first factor was humic acid in four levels of 0, 0.2, 0.5, 1 g/l, and the second factor was fulvic acid in four levels of 0, 0.2, 0.5, 1 g/l. Cuttings were taken from the plant in late March. Two weeks after transferring the rooted cuttings to pot, the treatments were applied on plants via fertigation. The traits measured in the experiment included plant height, mean number of nodes, internode length, leaf number, leaf length, leaf width, leaf area, root length, root fresh weight, leaf fresh weight, shoot fresh weight, aerial organ fresh weight, root volume, aerial organ volume, root dry weight, leaf dry weight, shoot dry weight, aerial organ dry weight, fresh and dry weights ratios of aerial organ to fresh weight. Statistical analysis of data was performed by 8-JMP software. LSD test was used to compare the means of the data.Results and Discussion Based on the results obtained, the combined use of humic acid and fulvic acid had a significant effect on height, fresh and dry weights of leaf, shoot, aerial organ and root, number of node and leaf and volume of aerial organ, fresh and dry weights of root, length and volume of root and the ratio of fresh and dry weights of aerial organ to root. Thus, combined use of humic acid and fulvic acid caused an increase in all the measured traits compared to the control treatment. Furthermore, an increase was observed in the length, width, and area of leaf, and internode length as the result of application of humic substances when compared to the control treatment. Organic fertilizers increase plant growth by improving soil conditions and increasing availability of plant to nutrients. Humic compounds cause changes in the specific distribution of cytokinins, polyamines and ATP by affecting the activity of root H+-ATPase and the distribution of root nitrate in the stem, thus affecting the growth of the plant stem. Humic materials increase plant growth by using different mechanisms such as hormonal effects, direct effect on plant cell metabolism, increase of cell division, chelating power and nutrient uptake, increase of soil ventilation and enhancement of plant photosynthesis by increasing Rubisco enzyme activity. Increasing nitrogen uptake leads to the increase in the growth of shoots and aerial organs. It also increases the number of branches in plants and increases the production of dry matter by increasing the production of photosynthetic materials.Conclusion In general, according to the results of this experiment, it can be concluded that application of humic substances (humic acid and fulvic acid) together, improved the growth characteristics of the plant and led to the better growth of the plant; therefore, these materials can be a good alternative to plant growth-stimulating chemical fertilizers.
Ornamental plants
N. Alavi Dehkharghani; S.H. Nemati; S.M. Zargarian
Abstract
Introduction
As the population grows and cities expand, the demand for more green spaces has also increased. Grass is widely recognized as one of the most important ground covers in the world. However, the development of green spaces is hindered by a severe shortage of water resources and challenges ...
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Introduction
As the population grows and cities expand, the demand for more green spaces has also increased. Grass is widely recognized as one of the most important ground covers in the world. However, the development of green spaces is hindered by a severe shortage of water resources and challenges associated with managing and maintaining grass. The composition of trees and plants may cause to inhibitory or stimulation effects on crops, called allopathic effects. Therefore, understanding the allopathic effects is important to determine appropriate methods of cultivation and product management to prevent interference of allopathic substances in the growth and production of products.
Materials and Methods
This study was performed in two separate experiments as a factorial based on completely randomized design at Ferdowsi University of Mashhad. In the first experiment, the effect of three different levels of plant residue powder (zero, 0.46 and 1 g) of three types of trees (Pine, Silk and Chinaberry) on germination and growth of Lolium prenne and Festuca arundinaceae grasses with four replications in the greenhouse was investigated. The second experiment, the effect of 5 ml of aqueous extract prepared from plant residues of the mentioned trees on germination and growth of the mentioned grasses in three replications in the laboratory was investigated. At the end of both experiments, some of morophology traits (weight, length, germination index) were measured. Minitab software was used to analyze the data obtained from both experiments.
Results and Discussion
According to the analysis of variance table of the first experiment, the results show that the simple effect of grass treatment on plant and root length, fresh weight, germination percentage and rate are significantly different. In the simple effect of treatment the quantity of plant residues, all traits have a significant difference. Also, in the simple effect of treatment of plant residue kind, plant length, root length, fresh and dry weight, germination percentage and rate were significantly different. Interaction grass and the quantity of plant residues treatment and the interaction of grass and kind of plant residues treatment, all measured traits had a significant difference. The interaction triple treatments plant length, root length, dry weight, germination percentage and rate differences were observed. Therefore, in the interaction triple treatments, the most and least plant lengths were observed related to the treatment of Lolium grass with 0.46 gr of Pine residue powder and the treatment of Festuca with 1 gr of Chinaberry residue powder. Also, the most and least root lengths were related to Lollium grass with 0.46 gr of Pine plant residue powder and Festuca grass with 1 gr of Pine plant residue powder. In the triple of dry weight the most amount was related to Festuca with 1 gr of Chinaberry residue powder and the least was related to Lolium control. The most and least germination percentages belonged to the control Festuca and lollium with 0.46 gr of pine plant residue powder respectively, and in the trait of germination rate, the most amount belonged to the control Festuca and the least to the control lollium has been observed. The results of the second experiment demonstrated a significant difference in all measured traits including grass treatment, plant length, fresh and dry weight, germination percentage and rate, and simple effect of plant extract. Moreover, the interaction of grass treatment and plant residue extract showed significant differences in root length, plant length, fresh weight, dry weight, and germination rate and percentage. Comparison of the mean interaction of grass treatment and type of plant residues revealed that the control Festuca had the highest plant length, while Lolium with Silk residue extract had the lowest. The longest and shortest root lengths were observed in control Lolium and Lolium with Silk residues, respectively. The highest and lowest fresh weight were recorded in Lolium control and Lolium grass along with Silk residue extract, respectively. For the dry weight trait, the highest amount was related to the treatment of Lolium grass with pine residue extract, while the lowest dry weight was observed in Festuca grass and Lolium grass with Silk residue extract. In terms of the germination percentage trait, control Festuca and Festuca with pine residue extract had the highest germination percentage, while Lolium with Chinaberry residue extract and Lolium with Silk residue extract had the lowest. The most and least germination rates belonged to Festuca control and Lolium with Chinaberry residue extract. From these discussions, it can be concluded that the allelchemicals in the powder extract of plant residues have had a significant effect on the yield of these two grasses and have reduced growth and germination. Decreased germination due to allelopathic stress can be due to different abnormalities in metabolic activity, seed saturation potential, death of some dividing cells and embryonic abnormalities.
Conclusion
Based on the results of both experiments, it can be concluded that Chinaberry and Silk trees have a stronger allelopathic effect compared to Pine. Additionally, the performance of both grasses in response to residues and extracts containing allelochemicals was slightly different. For instance, in the second experiment, the impact of Chinaberry extract reduced plant length by 28%, root length by 89%, dry weight by 16%, germination percentage by 75%, and germination rate by 85% compared to the Festuca control treatment. Similarly, the effect of Chinaberry extract on Lolium grass resulted in a 96% reduction in plant growth, 97% reduction in root length, 98% reduction in wet weight, 50% reduction in dry weight, 89% reduction in germination percentage, and 89% reduction in germination rate compared to the Lollium control treatment.
Ornamental plants
V. Ghasemi; A. Ehtesham Nia; A. Rezaei Nejad; H. Mumivand
Abstract
Introduction
Salinity stress impairs the absorption of elements such as potassium, leads to decrease in water and minerals, or due to an increase in Na+ effects the absorption of other elements. Salinity of water and soil is one of the obstacles to the expansion of agriculture in most part of ...
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Introduction
Salinity stress impairs the absorption of elements such as potassium, leads to decrease in water and minerals, or due to an increase in Na+ effects the absorption of other elements. Salinity of water and soil is one of the obstacles to the expansion of agriculture in most part of the world. Salinity causes several physiological and morphological changes in plants and affects growth and photosynthesis. Salinity stress also affects the absorption of nutrients, and finally the plants sensitivity to stress increases. High concentrations of Nacl in rhizosphere reduce the water potential and cause physiological drought stress. In addition, salinity stress can cause ion toxicity and imbalance, which can damage the plant. Salinity stress has been shown to reduce plant biomass by decreasing photosynthetic capacity and chlorophyll content. As stress increases, stomatal conductance and CO2 assimilation decrease, which both negatively impact photosynthesis and lead to a decrease in plant growth. Dianthus is an annual or perennial plant that produces velvety flowers in various colors. Due to its resistance to cold and wide range of colors, it is commonly used in landscaping. However, limited research has been conducted on the response of Dianthus to environmental stress, making it important to investigate its behavior under such conditions.
Material and Method
This research was conducted at greenhouse of municipality of Khomein, Iran. The statistical design was used in the factorial experiment based on CRD. Experimental factors included salinity stress (0, 10, 20, 30, 40, 50, 60, 70, 80, 90 mM) and cultivars (Barbarin and Diana). After preparing the seeds, it is first disinfected using sodium hypochlorite and then planted in plastic pots containing soil, sand and manure. At the end of the experiment, morphological traits, stomatal conductance, photosynthesis rate, Na+, K+ and Na+/K+ was also examined. Gas exchanges were measured using an exchange measuring device (LCA4, ADC Bioscientific,Ltd., Hoddesdon, England). At the time of measuring gas exchanges, the temperature under chamber was 26-29 C and relative humidity was 58-62%. (stomatal conductivity is based on mmol/m2/s and photosynthesis in µmol/m2/s). To measure the concentration of Na+ and K+, the leaf first turned to ash (at 550 C). Then 5 ml of hydrochlorid was added to dissolve the sample and the volume of the filtered solution was reduced to 50 ml with distilled water and the concentration of Na+ and K+ was measured with flame meter. In order to measure the fresh weight of leaves and roots, plant components were separated. Fresh weight was recorded with a scale and then samples were placed in the oven (for 48 h) and weighted again to measure dry weight. Leaf area was measured with a leaf guuge device (A30325) and plant height and root length using a ruler. Statistical analysis of data was performed using Mini Tab and Excel software.
Results and Discussion
Results showed that salinity stress generally affected the growth of both carnation cultivars and reduced vegetative and reproductive growth. According to the results obtained from the study, fresh and dry weight of shoot, root and leaves, root length, plant height, stem diameter, diameter and number of flower, lateral shoot number, stomatal conductance, photosynthesis rate, K+ concentration in Diana and Barbarin cultivars decreased with increasing salinity level. Na+ concentration and Na+/K+ increased with increasing salinity and these two traits were higher in Diana than Barbarin cultivar, which indicates lower resistance of Diana cultivar. The plant's first response to stress is to reduce its leaf area, which reduces the supply of photosynthetic material to the growing parts and consequently hinders growth and flowering. Salinity stress and high osmotic potential in the rhizosphere greatly affect photosynthesis as they decrease pore conductivity. Moreover, excessive absorption of Na+ can interfere with the absorption of other elements, thereby restricting plant growth. Potassium (K+) is an essential inorganic molecule that plays a crucial role in increasing plant resistance to stress. It helps in maintaining turbidity, promoting cell development, and regulating stomatal function. In this study, salinity stress affected the growth and yield of both carnation cultivars, and with increasing stress, all morphological traits decreased. This stress also reduce photosynthesis by reducing stomatal conductance and subsequently reduce other growth characteristics. Growth reduction was observed at high salinity stress concentrations in both cultivars. However, barbarin cultivar showed higher resistance than Diana
Ornamental plants
Davood Vafadari Komarolya; M. Kafi; M. Khansefid
Abstract
Introduction
As urbanization and population density increase, numerous issues arise in society, including a heightened risk of contagious diseases among the population, putting society at risk and in crisis. The purpose of this study was to identify preventive factors for individuals in the community ...
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Introduction
As urbanization and population density increase, numerous issues arise in society, including a heightened risk of contagious diseases among the population, putting society at risk and in crisis. The purpose of this study was to identify preventive factors for individuals in the community to avoid attending urban parks during the COVID-19 pandemic, as well as to evaluate the capacity of these places to promote public health and their functionality during the pandemic.
Materials and Methods
Using library resources and semi-structured in-depth interviews, the research data questionnaire was obtained and for sampling and determination of sample size, simple random sampling method and Cochran formula related to unknown statistical population with error level of 0.05 were used, respectively. Then, in order to analyze the data, the first question which was prioritized was 4-1 points from the first to the fourth priority and the mean score was calculated and the same process was implemented for the second part questions, respectively. After collecting the questionnaires, the data were extracted and the frequency of each of the options in the questions was determined, then to investigate the first part question which was related to the barriers to the presence of people in urban parks during the pandemic period and should be prioritized, i.e. assigning numbers 1 to 4 based on the participants' opinions, the priority was 4 points for priority 1 score 4, priority 2 points. 3, priority 3 points 2 and priority 4 points 1 selected, After averaging the relevant score, comparing them with each other, the most important barriers were mentioned in the results section, respectively. Also, in order to investigate the questions of the second part, the first question was related to the capacity of urban parks to promote public health in pandemic conditions and should have been answered as a single choice for the very significant option of score 4, the significant option of score 3, the average score option 2 and the low-score option 1, and after the average of the relevant points and comparing it with the average capacity of the park was selected. Some of the general health promotion during pandemic were identified and mentioned in the results section.
Results and Discussion
The study revealed that the most significant barrier to people's presence in urban parks was the absence of health warning signs, with an average score of 3.1. Additionally, the capacity of urban parks to enhance public health received a very significant average score of 3.3. However, the performance of these parks during the COVID-19 pandemic was rated as poor, with an average score of 1.4. Other barriers identified to people's presence in parks include:
- Non-conformity of urban parks design with pandemic conditions
- Inappropriate layout of furniture in urban parks
- Inappropriate shape, material and type of furniture in urban parks in terms of public health
Also, the overall results of urban parks capacity in increasing public health and performance of these places during covid-19 pandemic are as follows:
In relation to the capacity of urban parks in order to increase public health in comparison with other urban uses, the results of the survey of the received data are that out of 230 people in the study, 99 people evaluated the capacity of these places as very significant (43%), 103 significant (45%), 21 moderate (9%) and 7 (3%).
In relation to how the current urban parks play a role in covid-19 pandemic compared to other urban uses, the results of the data survey are as such that out of 230 people present in the research, 5 people performed this Places were assessed as excellent (2%), 11 were good (5%), 53 were moderate (23%) and 156 were weak (70%).
Conclusion
Overall, it can be concluded that urban parks have the potential to significantly promote public health, but during the pandemic period, their effectiveness was limited due to various barriers. It is recommended that designers, urban planners, and health professionals work together to create multi-functional designs that address existing barriers as much as possible. This would enable people to attend urban parks during the pandemic with less concern and potentially reduce the negative consequences of pandemic outbreaks and quarantine.
Ornamental plants
Afsaneh Hooshmand; Mitra Aelaei; Masoud Arghavani; Fahimeh Salehi
Abstract
Introdaction
Heavy metals are one of the most important environmental contaminants, particularly in soil and water sources. Mining and metal mining activities are major factors in soil contamination and generally surface soil around mines contain high amounts of these metals. Lead (Pb) is one ...
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Introdaction
Heavy metals are one of the most important environmental contaminants, particularly in soil and water sources. Mining and metal mining activities are major factors in soil contamination and generally surface soil around mines contain high amounts of these metals. Lead (Pb) is one of the heavy metals and important pollutant in arid ecosystem. The use of plants to remove contaminated soil or phytoremediation is an economical method. Today, due to increasing the pollution of soil sources and resultant problems, identification of the resistant plant species against soil pollution is essential. Using lead-contaminated soils requires their decontamination and improvement. There are different methods to remove these pollutions, one of them is the use of phytoremediation to remove pollutants from water and soil or to reduce them. Among the plants that as an ornamental plant can have a covering role in the green space and also perform the work of phytoremediation is the ornamental cabbage plants (Brassica oleracea L.). In this regard, this study was conducted with the aim of investigating the effect of lead heavy metals and the use of brown algae (Polycladia indica) and spirulina (Arthrospira platensis) as biofertilizers on ornamental cabbage plants in the direction of plant treatment. In addition, due to the presence of polysaccharide compounds such as carrageenan and alginate in the cell wall, algae (seaweeds) have a higher ability to absorb many heavy metals.
Materials and Methods
The experiment was conducted as factorial based on a completely randomized design in 2020 at the research greenhouse of Zanjan University. The studied factors including lead from lead nitrate source Pb(No3)2 with three concentrations (0, 25 and 50 mg/kg) were applied to the potting soil in four replications in two stages with an interval of two weeks. The second factor was included no algae, brown algae (Polycladia indica) and spirulina (Arthrospira platensis), which occurred in four replications. The measured traits included morphological traits: number of leaves, leaf surface index. Wet and dry root weight, and physiological traits included total chlorophyll content, total leaf antioxidant, peroxidase enzyme, glycine betaine, malondialdehyde, and leaf lead and phosphorus content. Data analysis was performed using SAS software and means were compared by LSD method.
Results
The results of the variance analysis showed that different levels of lead and the application of algae had a significant effect on the number of leaves per plant, leaf area index, weight, and drying of roots, total chlorophyll, and antioxidants. Moreover, the interaction effect was significant for leaf area, root fresh and dry weight, antioxidants, and leaf lead content. The simple effect of lead at p≤0.01 significantly affected glycine betaine, malondialdehyde, and leaf phosphorus. When comparing the average mutual effects of lead and algae application, it was found that the treatment with no use of lead and spirulina algae resulted in the highest weight and dry weight of the root, with an average of 11.19 and 3.625 grams, respectively. Additionally, despite the decrease in dry weight of the root due to increased lead concentration, using algae, especially for ornamental cabbage (Brassica oleracea L.), increased the dry weight of the root. The presence of natural plant hormones, organic substances, carbohydrates, fiber and amino acids in algae accelerates rooting, reduces stress caused by heavy metals and absorbs more water due to the presence of o developed root system. Also according to the results of comparing the amount of leaf lead with increasing lead, algae as an auxiliary factor can reduce the amount of uptake in the plant. Leaf phosphorus was also significant due to the simple effect of lead and algae. The highest amount of phosphorus with an average of 0.56% was observed in spirulina and the lowest with 0.48% was observed in control.
Conclusion
In general, due to the toxicity of lead metal even in low concentrations, sufficient attention should be paid to the sources of this pollutant entering the environment. In this study, the effective parameters on the uptake of heavy metal lead from the soil by spirulina and brown algae were investigated. The findings of this study indicate that the ornamental cabbage plant is capable of sustaining its growth in the presence of lead and has a high resistance to this heavy metal while simultaneously absorbing it from the soil. Furthermore, the addition of algae as an auxiliary factor can improve the growth of ornamental cabbage under adverse conditions. Therefore, it is recommended that this plant be further examined for its potential to absorb other heavy metals.
Ornamental plants
D. Kazemi; M. Dehestani Ardakani
Abstract
Introduction Different aspects of light including intensity, quality (spectra), and duration (photoperiod) can influence plant growth and development. The growth and development of ornamental plants are also influenced by light intensity and quality. Energy saving in greenhouse production has received ...
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Introduction Different aspects of light including intensity, quality (spectra), and duration (photoperiod) can influence plant growth and development. The growth and development of ornamental plants are also influenced by light intensity and quality. Energy saving in greenhouse production has received much attention lately. One reason for the interest in utilizing light quality to modulate plant growth and morphology is the recent development of light-emitting diodes (LEDs) as a lighting source in greenhouse production. Such small diodes can easily be placed close to the canopy and can be used to apply a narrow-band light spectrum to the plants. Specific requirements for light spectral distribution for specific processes like morphogenesis, photosynthesis, chlorophyll and anthocyanin synthesis have been determined in different species. The aim of the current study was to investigate the biophysical properties of chlorophyll fluorescence of Hypoestes phyllostachya plants in response to different light spectra.Materials and Methods Research experiments were conducted on Hypoestes phyllostachya in a completely randomized design with six treatments of different light quality and three replications. The seeds were planted in plugs and in a mixture of 70% peat moss and 30% perlite. Seedlings were grown in natural greenhouse (control) and LED (100% Blue, 15% Blue +85% Red, 30% Blue +70% Red, 15% Blue +65% Red + 20% White and 30% Blue +50% Red + 20% White). Since the main goal of the study was to compare the effect of LED light quality with sunlight in conventional greenhouse conditions. The LED treatments were applied from fourth month old seedlings until five weeks in a growth chamber with the light/dark regime of 15/9 hours, 23±5°C temperature, and 65±5% relative humidity. While, their pots in the greenhouse with 55±5 mol.m-2.d-1 DLI, 21±5°C average daily temperature and 65±5% relative humidity (Data logger 8808 temp. + RH) were regarded as the control treatment. After five weeks, the fluorescence chlorophyll was measured.Selected leaves were dark-adapted prior to the measurements and OJIP protocol was applied using a fluorometer (FluorPen FP 100-MAX, photon system instruments, Drasov, Czech Republic). The fluorescence measurement was performed using a saturating. FluorPen software was used to extract data from the original measurement. Data extracted were used to analyze the following data according to the equations of the JIP test: fluorescence intensities at 50 μs (F 50 μs, considered as the F0), 2 ms (J-step denoted as FJ), 60 ms (I-step, FI), and maximum fluorescence intensity (FM, FP). The JIP-test was used to quantify the amount of energy that flow via the PSII. Performance index was measured on the absorption basis (PIABS, a multi-parametric expression). Probability that a trapped exaction promote an electron in electron transport chain (ETC) beyond the primary acceptor Quinone (QA−), maximum quantum efficiency of PSII (FV/FM), specific energy fluxes per reaction center (RC) for energy absorption (ABS/RC), trapped energy flux (TR0/RC), electron transport flux (ET0/RC) and dissipated energy flux (DI0/RC) were calculated according. Finally, the data were statistically analyzed with SAS (9.4) software package, and the means were compared by LSD test at p < 0.05 level. Results and Discussion Fast Chl fluorescence induction curves (OJIP) was the main parameters used for the screening of different light treatments. OJIP test is shown to be a proxy to detect PSII bioenergetics and indicates changes in the status and function of PSII reaction centers, antenna, as well as in donor and acceptor sides of PSII. The maximum quantum yield of PSII (FV/FM) and relative maximal variable fluorescence (Fm/F0), significantly increased in 15% Blue +85% Red, 30% Blue +70% Red, 15% Blue +65% Red + 20% White. PIABS, one of the OIJP test parameters that provide valuable awareness about photosynthtic performance, considerably decreased under control and 30% Blue +50% Red + 20% White treatment. Unlike PIABS, ET0/RC did not show a significant difference under different treatments. The specific energy fluxes per RC for energy absorption (ABS/RC) significantly increased under control and 30% Blue +50% Red + 20% White treatment. TR0/RC increased in plants under control and 30% Blue +50% Red + 20% White treatment. Treated plants under 15% Blue +85% Red and 30% Blue +70% Red showed the lowest in dissipated energy flux (DI0/RC). During an ideal condition without any additional stress, the total PSII pool can be completely inactivate and retrieve without a detectable photoinhibition.Conclusion When plants exposed to 100% Blue and 30% Blue +50% Red + 20% White treatments as well as in control plants, FM/F0, FV/FM and PIABS significantly decreased. Also ABS/RC, TR0/RC and DI0/RC, significantly increased.
Ornamental plants
M. Osku; A. Khandan Mirkohi; R. Naderi
Abstract
Introduction The genus Chlorophytum (also known as spider plant) which is mainly cultivated as an ornamental plant for its slash and colored leaves, specifically distributed in the pantropic regions. It is a perennial rhizomatous plant with often short and indistinct rhizomes, while with thicker ...
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Introduction The genus Chlorophytum (also known as spider plant) which is mainly cultivated as an ornamental plant for its slash and colored leaves, specifically distributed in the pantropic regions. It is a perennial rhizomatous plant with often short and indistinct rhizomes, while with thicker or slightly fleshy roots. The roots of these species are considered as one of the important phytochemical components. the use of Chlorophytum comosum as a contaminant accumulator has already been documented in the literature.This plant is a soil conditioner and can absorb lead, cadmium, Se and As while its leaves accumulate mercury. It is also able to absorb toxic organic pollutants such as formaldehyde and benzene and is also able to retain CO2. Leaf surface morphology has been shown to affect the ability of a particular plant to retain contaminants. Chlorophytum comosum introduced as a plant that requires high nitrogen. Nitrogen is an essential macro element for the growth and development of plants which involved in many physiological reactions and it is one of the elements that plants need in all their activities. The effect of N form on plant growth depends on plant species and nitrogen level of the soil. Plants absorb both ammonium (NH4+) and nitrate (NO3-) from soil solution, and these two mineral forms are their most important sources of nitrogen to supply the plant demand. Absorption of ammonium by plants requires less energy than absorption of nitrate. It seems that most plants have the best performance in a certain ratio of nitrate to ammonium (NO3-/NH4+ ratio). This ratio seems to regulate the distribution of absorbed nitrogen between the branches and roots. It may also vary between species. The optimal ratio may also depend on the environmental conditions such as pH, light intensity, and root zone temperature. This study was performed to determine the effect of different levels of ammonium nitrate on growth, yield factors and ornamental aspects of the spider plant as a desired ornamental product. The use of ammonium nitrate to meet the houseplants demand considering the supply of both types of nitrogen sources, increases the yield and quality of these plant. However, despite the importance of the nitrogen in the performance of this ornamental plant (Chlorophytum comosum), the desired amount of nitrogen for its growth and quality has not yet been reported. Therefore, the present study was conducted to investigate the effect of different levels of ammonium nitrate on the growth and physiological characteristics of spider plant to find the best level of application of ammonium nitrate fertilizer as an easily available source to increase the growth and visual quality of this plant.Materials and Methods This research was conducted based on randomized complete block design (RCBD) with four treatments and three replications. Treatments include four levels of ammonium nitrate of 100 (control), 200, 400, 600 mg-1 kg of soil. Treatments applied first at the substrate preparation process and then was applied in the one third depth of each pot, monthly. Desired factors such as morphological characteristics (plant height, leaf number, stolon number, fresh weight, dry weight, root fresh weight, root dry weight, root volume, root depth, root length, pot weight, leaf area) and physiological characteristics (total chlorophyll, total protein, texture nitrate and proline) were evaluated. Also soil analysis was performed before starting of the experiment. Statistical analyses of the data for examined traits were performed using SAS software and comparisons of means using Duncan's multiple range test, at 5% probability level.Result and Discussion The results indicated that the application of ammonium nitrate fertilizer significantly improved most of the studied traits. Supplying ammonium nitrate fertilizer at desired level meet the nitrogen demand of Spider plant during the growth and improved production of biomass. The plant height, leaf number, fresh weight, dry weight, root fresh weight, root dry weight, and leaf area were increased by increasing ammonium nitrate level. Nitrogen fertilizers play an important role for increasing plant yield by expanding shoots and producing sufficient carbohydrates. In addition to plant growth, they also affect plant morphology. Maximum amount of protein, nitrate of tissue and total chlorophyll observed in 400 mg-1kg of ammonium nitrate level. Nitrogen is one of the essential elements that plays an important role in the production of chlorophyll and protein, therefore the use of nitrogen fertilizers leads to synthesis of chlorophyll and protein at higher level. The highest amount of proline (11.20 μg-1 mL) was measured at 600 mg-1kg of ammonium nitrate level and the lowest (3.57 μg-1 mL) in the control, because with high consumption of nitrate, the plant needs more water and nitrogen is a structural component of proline. Accumulation of proline helps the plant to survive and recover after drought stress.Conclusion According to the results of our experiment, application of nitrogen fertilizer had a positive effect on growth, and consequently led to increase the plant vegetative yield. Treatment of 400 mg-1kg of ammonium nitrate level increased growth and yield factors and the ornamental aspect of Spider plant as a desired ornamental crop. Application of 400 mg-1kg of ammonium nitrate level are recommended to access an acceptable quantitative and qualitative yield in this plant.
Ornamental plants
M. Piri; Z. Jabbarzadeh
Abstract
Introduction Lisianthus (Eustoma grandiflorum) from Gentianaceae family is from wild flowers of north and west America. Lisianthus, a relatively new floral crop to the international market, quickly ranked in the top ten cut flowers worldwide due to its rose-like and blue flowers. It is also widely ...
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Introduction Lisianthus (Eustoma grandiflorum) from Gentianaceae family is from wild flowers of north and west America. Lisianthus, a relatively new floral crop to the international market, quickly ranked in the top ten cut flowers worldwide due to its rose-like and blue flowers. It is also widely used as a flowering potted and bedding plant. Lisianthus ‘Mariachi Blue’ is cultivated as a cut flower. Salicylates have very beneficial effects on plant growth and development. The effect of phenolic compounds in many biochemical and physiological processes including photosynthesis, ion adsorption, membrane permeability, enzyme activity, flowering, stimulation of plant resistance systems, heat production and plant development has been proven. The most famous member of this group is salicylic acid, which as a simple phenolic compound, is naturally produced by plants. Salicylic acid (SA) is considered to be plant signal molecule that plays a key role in plant growth, development, and defense responses. Polyamines (PAs) are ubiquitous and biogenic amines that have been implicated in cellular functions in living organisms. In plants they have been implicated in a wide range of biological processes including cell division, cell elongation, senescence, embryogenesis, root formation, floral initiation and development, fruit development and ripening, pollen tube growth and plant responses to biotic and abiotic stress. Sodium nitroprusside is a nitric oxide releasing agent. Nitric oxide is a gaseous free radical that can disperse very rapidly through cell membranes due to its gaseous nature and medium shelf life, without a carrier. Nitric oxide (NO) is an unstable environmentally-friendly gas radical that is used to protect the postharvest longevity of different horticultural crops. In addition to controlling harvested crop senescence, NO is involved in many plant processes, e.g., germination, growth and development, photosynthesis, pigment synthesis, defensive system, and many others. In the present study, we investigated the effects of foliar application of salicylic acid, spermidine and sodium nitroprusside on some morpho-physiological characteristics and vase life of lisianthus flowers ‘Mariachi Blue’.Materials and Methods This study was conducted based on a completely randomized design with 10 treatments, 4 replications which each replication containing 2 pots. The treatments were included spermidine at concentrations of 0.5, 1 and 2 mM, salicylic acid at concentrations of 0.5, 1 and 1.5 mM, sodium nitroprusside at concentrations of 50, 100 and 200 μM and control (without any application of growth regulators) as foliar application at intervals of 15 days for 2 months. Plant characteristics including leaf area, stem length, fresh and dry weight of leaves and flower, number of buds, flowers’ length and diameter, photosynthetic pigments and vase life were assayed. To perform analysis of variance and compare the mean of the studied traits, SAS software version 9.1 was used. The means were compared using the Tukey multi-domain method at a probability level of 1%. Also, Excel (2016) software was used to draw the chart. Results and Discussion The results obtained from analysis of variance in this study showed that the effect of growth regulators used in the study was significant at the level of 1% probability on all morphological traits measured, photosynthetic pigments and vase life of lisianthus flowers. Mean comparison graphs showed that salicylic acid, spermidine and sodium nitroprusside had a positive effect on some morphological traits, photosynthetic pigments and vase life compared to control. It can be concluded that, salicylic acid caused to increase all parameters except the flowers’ fresh weight compared to control. Spermidine increase stem length, leaf fresh weight, flowers’ fresh and dry weight, length, and diameter, chlorophyll index, chlorophyll b, and carotenoid and vase life of flowers. Also, sodium nitroprusside had beneficial effects on all parameters in this research except leaf area, leaf dry weight, chlorophyll a and vase life of flowers. Salicylic acid plays an important role in regulating some physiological processes of plants such as growth and development, ion uptake and transport, stomatal conductivity, and membrane permeability, which is effective in plant photosynthesis and with increasing photosynthesis, plant growth rate increases. Polyamines such as spermidine are involved in a wide range of developmental stages including cell division, embryogenesis, root growth, and flowering. Sodium nitroprusside is involved in the most important plant processes such as photosynthesis, respiration, growth and cell division. Probably, these growth regulators, due to their effect on plant growth, flowering, as well as photosynthetic pigments, have caused the increment of plant biomass and vase life.Conclusion In the present study, the effect of salicylic acid, spermidine and sodium nitroprusside on some growth and flowering characteristics, photosynthetic pigment and vase life of Eustoma grandiflorum ‘Mariachi Blue’ was assayed. According to the results of the present study, it can be concluded that these growth regulators improved growth indices, flowering parameters, photosynthetic pigment and vase life of flowers. According to the results, the appropriate concentrations for salicylic acid were 1 mM, for spermidine, 1 mM and for sodium nitroprusside were also 50 and 100 μM.
Ornamental plants
M. Karimi; F. Salimi; A. Pakdin Parizi
Abstract
Introduction Plant size control is one of the most important factors in the production of ornamental plants. Plant size can be limited by a variety of methods, including genetic control, environmental conditions, and the use of plant growth retardants. Lily (Lilium sp.) is one of the most important cut ...
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Introduction Plant size control is one of the most important factors in the production of ornamental plants. Plant size can be limited by a variety of methods, including genetic control, environmental conditions, and the use of plant growth retardants. Lily (Lilium sp.) is one of the most important cut flowers with different species and cultivars. Some lilies can grow up to one meter in height. Usually the appropriate height of the stem for pot use is 40-30 cm, which is achieved by using growth regulators. This study aimed to investigate the role of uniconazole and cycocel to control height, quantitative and qualitative characteristics of Lilium.Materials and Methods This study was carried out in a factorial experiment based on completely randomized design. Uniconazole (0, 5 and 10 mg L-1) and cycocel (0, 1000 and 1500 mg L-1) were the first factor and application methods of the above compounds (immersion application and foliar application) was the second factor. Disease-free bulbs (with a circumference of 15 cm) Lily (Longifiorum × Asistic cv. Eyeliner) was purchased from Saei Gol Company in Tehran. To apply the immersion treatment, the bulbs were immersed in a solution of cycocel (CCC) and uniconazole (UN) for 7 minutes before planting. Then they were planted in plastic pots. In foliar spraying treatments, the bulbs were first planted in pots and when the stem height reached 10 cm, they were sprayed with CCC and UN. Water was used for control treatment. Leaf number, plant height, total chlorophyll, total phenol, flower diameter, enzyme activity (PPO, GPX or CAT) and time of budding were measured. Analysis of variance was performed using SAS software and mean comparisons were analyzed by the least significant difference test.Results and Discussion The effect of growth retardant, the application method and their interaction was significant on stem height. The shortest plants were observed in foliage application of 10 mg L-1 UN which was not significantly different from the concentration of 10 mg L-1 UN in immersion method. The mechanism of growth retardants is to inhibit the biosynthesis of gibberellins. Therefore, they act as anti-gibberellins to reduce plant height. Uniconazole inhibits the biosynthesis of gibberellins by blocking kaurene oxidase, a P450 enzyme. The largest diameter of lily flowers was observed in immersion application of 1500 mg L-1 CCC however, there was no significant difference between flower diameter of mentioned treatment with immersion method of 1000 mg L-1 CCC and foliar application of 10 mg L-1 UN. Growth retardants increase endogenous cytokinin levels, resulting in increased cell division and improved flower growth and flower diameter. The effect of growth retardant on number of leaves was significant. The highest numbers of leaves were observed in 1000 and 1500 mg L-1 CCC. The effect of growth retardant, the application method and their interaction was significant on chlorophyll and phenol contents. The highest chlorophyll content was observed in immersion application of 10 mg L-1 UN. Growth retardants appear to increase chlorophyll content due to increased cytokines. The results of this study showed an increase in total phenol in plants treated with uniconazole 10 mg L-1. Growth retardants have been reported to increase phenol content by increasing plant resistance to environmental stresses. Catalase enzyme activity was significantly affected by growth retardant. The highest activity of CAT enzyme was related to CCC at 1500 mg L-1. The effect of growth retardant and their interaction was significant on GPX enzyme activity. The highest enzyme activity was obtained in plants sprayed with 1000 mg L-1 CCC. Growth retardants have been reported to increase enzyme activity, causing plant resistance to environmental stresses and delaying lipid peroxidation and membrane degradation.Conclusion Considering that one of the most important goals in the present study was the production of dwarf lilium, it can be said that uniconazole 10 mg L-1 (foliar application and immersion) had a significant effect in controlling stem height compared to other treatments. The effect of this treatment on other traits such as flower diameter, total chlorophyll and total phenol was also significant. The time of budding, leaf number and activity of CAT and GPX enzymes was better in cycocel treatment with a concentration of 1500 mg L-1. Therefore, the use of uniconazole can be recommended for the production of dwarf plants, considering that it works better in two important traits, including controlling stem height and increasing flower diameter. It is also suggested that since the cycocel treatment was effective in increasing enzymatic activity, the effect of this treatment on plant resistance to environmental stresses should be investigated.
Ornamental plants
B. Moradi Ashour; K. Parvizi; M.H. Azimi
Abstract
Introduction
The evaluation of morphological, phenological and agronomical characteristics is one of the first steps for the initial study of germplasm. It can also be conferred as basic information for the breeder to study genetic diversity for particular purposes. Chrysanthemum (Chrysanthemum ...
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Introduction
The evaluation of morphological, phenological and agronomical characteristics is one of the first steps for the initial study of germplasm. It can also be conferred as basic information for the breeder to study genetic diversity for particular purposes. Chrysanthemum (Chrysanthemum morifolium) is a perennial herbaceous plant of the family Asteraceae with simple coniferous leaves and alternate arrangement on its branched stems and has composite flowers. The first stage in breeding programs is to study genetic variation of the selected plants. This study was conducted in order to evaluate the genetic variation of flower traits for selected Chrysanthemum genotypes for three years. Researchers use different methods to estimate genetic diversity of plants including DNA markers, isozymes and morphological traits. Use of morphological traits that are easily measured and have high heritability is a convenient tool to assess the level of genetic diversity of plants.
Materials and Methods
The origin of the tested genotypes was from the gene bank of the Research Institute of Flowers and Ornamental Plants. The results of random crosses between different chrysanthemum clones were evaluated. The research was conducted for four consecutive years. The aim of the first year experiment was positive selection of genotypes. In fact, the best genotypes were selected. In addition, negative selection of different genotypes was performed. During this selection period, similar genotypes were removed. Selected genotypes (20 genotypes) were evaluated based on a completely randomized design with three replications using seven morphological traits including number of flower per plant, period of flowering, flower diameter, number of petal row, petal length, Fresh weight and dry weight of flower. Statistical analyses including analysis of variance, correlation coefficient, and heritability, phenotypic and genotypic coefficient of variation were estimated using SAS 9.0 software.
Results and Discussion
After performing Bartlett test and confirming the uniformity of variances, combined analysis was performed for three years. The results of analysis of variance showed that the effect of the year was significant only for the number of flowers per plant and the flowering period. The results of three-year analysis of variance showed that there was significant difference among the genotypes for the number of flowers per plant, flowering period, number of petal rows, fresh and dry flower weight. There was a significant difference (p≤0.05) among the years only in flowering period and number of flowers per plant. The highest variation observed between flowering period and flower diameter. The highest coefficient of phenotypic and genetic variation obtained for the number of petal rows, flower fresh weight and petal length. The lowest coefficient of phenotypic and genetic variation obtained for fresh and dry flower weight and number of flowers per plant. The highest positive genetic and phenotypic correlation coefficient estimated between flowering period with flower diameter, number of rows of petals and fresh weight of flowers which is important for the simultaneous breeding of these traits. The results of this study showed that flower diameter, flowering period, petal length and number of petal rows showed high general heritability. Therefore these results indicate that the selection process for these traits is effective and can be used in the breeding programs. The results of this study showed that highest number of petal rows belonged to B136 genotype. Genotype 31 with forty-three days of flowering period had the highest flowering length compared to other genotypes. GenotypeC85 had 202 flowers per plant. These genotypes can be used as parents especially to increase the flowering period and the number of petal rows due to the general heritability of over fifty percent of these traits. It is also suggested that traits such as petal color and resistance to important pests (including black chrysanthemum aphid, flower thrips pest) and important diseases (including Fusarium wilt, verticillium wilt and leaf spot) should be studied. The superior genotype can be selected if statistically significant difference observed among of genotypes.
Conclusion
It is a fact that chrysanthemums has characteristics such as variation of flower shape and color, plant size, form and flowering period that is widely used in landscape. In this research significant difference observed among the genotypes. Also some of measured traits had a high general heritability due to the positive and significant correlation of these traits that can be used to improve other genotypes and their traits.
Ornamental plants
E. Saeedipooya; A. Tehranifar; A. Gazanchian; F. Kazemi; M. Shoor
Abstract
Introduction
Turfgrasses, as one of the important components of urban landscapes, have played a vital role in this regard. However, the main problems of turfgrass development are the cost of turfgrass seeds, maintenance costs such as moving, as well as the high water requirement in arid and semi-arid ...
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Introduction
Turfgrasses, as one of the important components of urban landscapes, have played a vital role in this regard. However, the main problems of turfgrass development are the cost of turfgrass seeds, maintenance costs such as moving, as well as the high water requirement in arid and semi-arid regions. Thus, the reduction of lawn culture in the landscape is one of the decision has taken in parks and green spaces organization of Tehran, Isfahan and even Mashhad. For over ten years, researchers have been looking for alternatives to conventional grass lawns to reduce the high cost of maintenance especially irrigation cost in urban landscapes. According to many researches, one of the potential ground cover alternatives that might be used instead of turfgrass is White Clover. Clover (Trifolium spp.) from Fabaceae family is a genus of about 300 species.
Materials and Methods
The aim of this experiment was to compare three common turfgrasses with two clover varieties as turf replacement to reduce landscape maintenance cost specially moving cost. So, some growth and qualitative factors of clover lawn: Trifolium repens var. Calway and Trifolium repens var. Pipolina (micro clover) and three turfgrasses of Festuca arundinacea L. and Lolium perenne L. and commercial sport turf mixture (from NAk-Nederland Ltd.) were compared together. This research was conducted in randomized complete block design with three replications in the research field of the Department of Horticultural Science and Landscape Engineering‚ Faculty of Agricultural‚ Ferdowsi University of Mashhad‚ Mashhad‚ Iran, during 2016 and 2017. The site (59º 38′ E and 36º 16 ′ N; elevation 989 m) is located in an arid and semi- arid region with mean annual rainfall 233.8 mm and long term averages of maximum and minimum temperature are 22.5 ºC and 9.3 ºC‚ respectively. Turfgrass plots were established by directly sowing the seeds in April, 2016. The planting rate of the seedling considering their pure live seeds (PLS) were 45 g.m-2 for Lolium perenne, 34 g.m-2 for Festuca arundinacea, 6.5 g.m-2 for Trifolium repens, 5.5 g.m-2 for micro clover and 39 g.m-2 for commercial mixture of sport turf. The plots were 1 m2 (1m×1m) in size and were prepared after plowing and leveling the soil. The seeds were hand sown and covered with a thin layer of leaf compost and sand.
Results and Discussion
According to the results in the first evaluation of emergence percentage, Lolium perenne had the highest emergence percentage. After 36 days from culture, all plants had 92-98 % coverage which did not have any significant difference among grasses with clover lawns. In terms of density, uniformity and weed density, there was no significant difference between the studied plants. In the other hands, white clover showed the best quality after clipping in both years. At the point of growth index, which have done in this experiment by measuring height and dry weight of clipping, grass lawns had the higher growth index in compered to clover lawn in both years. Festuca arundinacea and Lolium perenne had the highest growth index and white and micro clover had the lowest growth. Also, with air warming, Festuca arundinacea became dominated plant in height and clipping dry weight. In July, Festuca arundinacea produced the highest clipping dry weight by 40 gr.m-2, Lolium perenne (19.52), commercial sport turf (15.68), white clover (6.24) and micro clover (0.36) gr.m-2.
Conclusion
One of the problems of landscape is reduction of maintenance costs such as mowing. So, the low growth of white and micro clover is a positive factor in reduction of the moving costs than turfgrasses. Also, the coverage and proper density of clover lawns are similar to grass lawns and did not have a significant difference with them. The character of low growth can be effective in reduction of irrigation costs in white and micro clover, which requires more research and examination in future. This is a positive point in the white clover and micro clover that do not need to move or cut every months. Almost, clover moving is recommended for removing their flower. Therefore, it is recommended to use white and micro clover as a replacement with less maintenance costs in landscape. Finally, the results of cultivation of grass and clover as monoculture in this study can be used to produce clover-grass mixtures suitable for the climate of our country (arid and semi-arid regions), instead of importing turf mixtures from European countries.
Ornamental plants
M. Hojatipour; M. Hassanpour Asil
Abstract
Introduction
Lilium flower is a perennial herbaceous flowering plant, belonging to the Liliaceae family. Position of lilies as the fourth best-seller cut flower in the world, as well as the increasing trend of demand for this flower in the global market, indicates the importance of improving the ...
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Introduction
Lilium flower is a perennial herbaceous flowering plant, belonging to the Liliaceae family. Position of lilies as the fourth best-seller cut flower in the world, as well as the increasing trend of demand for this flower in the global market, indicates the importance of improving the quality and solving the sustainability issues of this flower. Gibberellins are one of the most important endogenous plant hormones involved in controlling plant dormancy. Gibberellin is a plant growth regulator that stimulates physiological responses in plants by affecting photosynthesis. Polyamines, including putrescine, spermidine, and spermine, are a group of plant growth regulators that have effects such as increasing cell division, biosynthesis of enzymes, regulating various developmental stages such as differentiation.
Materials and Methods
This study was performed to investigate the effect of gibberellic acid and putrescine on growth, flowering and vase life of Lilium cut flowers. Experiment was performed as factorial based on completely randomized design, included 16 treatments with 3 replications and 2 pots in each replication. The culture medium containing mold leaf soil, sand and perlite (1:1:1) and was prepared by disinfection with fungicide. The first treatment consisted of concentrations of 150, 300 and 450 mg/L gibberellic acid and onions were pre-treated by immersing for 24 hours. The second treatment consisted of concentrations of 0.5, 1 and 2 mM putrescine which was sprayed at the beginning of budding and continued every two weeks until the first bud flower coloring. Growth period conditions in green house were controlled. In this study, different parameters such as bud number, flowering stem length, fresh weight of cut flowers, relative fresh weight of cut flowers, water uptake of cut flowers, vase life, leaf chlorophylls a, b and total, petal carotenoid, percentage of petal cell membrane stability and total soluble solids of petals were examined.
Results and Discussion
The results showed that the application of gibberellic acid and putrescine improved the number of buds and increased cell membrane stability. Actually, gibberellic acid preserves the cell membrane by preventing the breakdown of proteins and increasing the pH, thus increasing the vase life. Also Putrescine protects cell membranes by removing free radicals. It is also known that gibberellic acid used at all levels in the experiment increased the height of the flower stem due to its role in cell division and elongation. Study of the flower stem water content and cut flower fresh weight, which are factors for longer vase life, showed that gibberellic acid increases the plant's ability to absorb water and increases these two traits. So that the highest cut flower fresh weight with 13 g difference compared to the control level belonged to the treatment level of 450 mg/L gibberellic acid. Also putrescine reduces plant water loss by increasing membrane permeability to calcium and increases the flower stem water content and cut flower fresh weight, which increases vase life. Also, gibberellic acid by creating water potential in the cell and putrescine by strengthening water relations and preventing blockage of water vessels increased the relative water uptake of cut flower. Thus, the greatest effect was observed on the third day post-harvest and the highest amount (2.47 ml. g-1 FW) on the third day belonged to the highest level of both treatments. Results also showed that all the levels of putrescine increased TSS due to its effect on the synthesis of sugars and carbohydrates in compared to control. The results showed that application of gibberellic acid and putrescine respectively at 300 mg/L and 2 mM, significantly increased the vase life compared to the control. The best vase life (15 days) occurred at 300 mg/L gibberellic acid and 2 mM putrescine. Although gibberellic acid increased growth and flowering of Lilium, but putrescine effectiveness on vase life of cut flower was more evident. The highest amount of leaf total chlorophyll (0.514 mg. g-1 FW) belonged to the treatment of 450 mg/L gibberellic acid and 2 mM putrescine and the lowest amount of leaf total chlorophyll (0.085 mg. g-1 FW) belonged to both treatments were at the control level. Also, in the study of petal carotenoid content, the highest amount belonged to the treatment of 450 mg/L gibberellic acid and 2 mM putrescine.
Conclusion
According to the results obtained from the present research, it can be concluded that use of gibberellic acid and putrescine had great effects on most of traits in compared to control treatment. The use of putrescine and gibberellic acid improves the flowering and vase life conditions by increasing water uptake and consequently increasing the relative fresh weight.
Ornamental plants
R. Abdi; Z. Jabbarzadeh
Abstract
Introduction The genus Rosa from the family Rosaceae with over 150 species is one of the most important ornamental plants in the world. From a commercial point of view, cut roses play a key role in trade of cut flowers. Nitric oxide regulates key physiological processes that depend on the concentration ...
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Introduction The genus Rosa from the family Rosaceae with over 150 species is one of the most important ornamental plants in the world. From a commercial point of view, cut roses play a key role in trade of cut flowers. Nitric oxide regulates key physiological processes that depend on the concentration of this compound such as hypocotyls growth, defensive responses, growth and development, photosynthesis, and phytoalexin generation in stressful conditions. Polyamines are key biomolecules that have a role to play in the regulation of many plants’ growth and development processes and their responses to different environmental stimuli. This study was performed to investigate the effect of foliar application of sodium nitroprusside (as a NO donor) and putrescine (as a polyamine) on ‘Avalanche’ rose in hydroponic conditions.Materials and Methods This study was conducted in the research and production greenhouses of Urmia University and the research laboratory of the Department of Horticultural Sciences of the Faculty of Agriculture in 2019-2020 on rose (Rosa hybrida ‘Avalanche). This experiment was conducted as a factorial trial based on completely randomized design with two factors including sodium nitroprusside in four concentrations of 0, 50, 100 and 200 μM and putrescine in four concentrations of 0, 1, 2 and 4 mM with 3 replications as a foliar application under hydroponic conditions in greenhouses and in pots. The treatments were applied two weeks after transplantation, every 15 day-interval for 4 months. In order to investigate the effects of putrescine and sodium nitroprusside on some morphological and physiological characteristics of plants, two weeks after the end of treatments, sampling was performed to measure morphological and physiological characteristics. The measured indicators included: fresh and dry weight of flowering stem, chlorophyll a, b and total chlorophyll, carotenoids and also in the postharvest stage were guaiacol peroxidase and ascorbate peroxidase enzymes activity and bending of flowering stem. The SAS software version 9.2 was used to analyze the variance and compare the mean of the studied traits. Comparison of means was performed using the Tukey’s range test method at a probability level of 1 and 5%. Also, Excel (2016) software was used to draw the graph.Results According to the means comparison of measured parameters, sodium nitroprusside along with putrescine increase the flowering stem fresh and dry weight, photosynthetic pigments of leaves and antioxidant enzymes activities at the postharvest stages. Sodium nitroprusside at a concentration of 50 μM with 4 mM putrescine increased the fresh and dry weight of the flowering stem. Also, the concentration of 100 μM sodium nitroprusside with 4 mM putrescine significantly increased chlorophyll a, b, total chlorophyll and carotenoid content compared to control. It should be noted that preharvest application of sodium nitroprusside along with putrescine cause to improve postharvest characteristics of rose. In this research, application of 100 and 200 μM SNP alone or with different concentrations of putrescine increased guaiacol peroxidase and ascorbate peroxidase activity and reduced bending of flowering stem of rose ‘Avalanche’ at the postharvest stage. Probably polyamines (such as putrescine) and nitric oxide increase photosynthesis potential with increasing photosynthetic pigments and protecting cell membranes thus increase growth and flowering traits of plants such as increasing the flowering stem weight of rose in this research. At postharvest stage, senescence of flowers is an inevitable phenomenon that cause to produce free radicles in plants. Free radicles injure the plant membranes lipids and change the antioxidant enzymes activities. This despite the fact that nitric oxide and putrescine protect antioxidant enzymes against free radicles as a result can improve vase life of rose. Conclusion Based on the results of the present study, it can be concluded that putrescine, with SNP, improves growth characteristics as well as increases the postharvest traits and quality of cut flowers of rose. According to the results, it is observed that among the different concentrations of putrescine, the concentration of 4 mM had the greatest effect on the growth and physiological parameters of rose while the concentration of 100 and 200 μM sodium nitroprusside had a greatest effect on physiological characteristics and postharvest traits of rose. In general, both SNP and putrescine had a positive and favorable effects on improving growth and postharvest indices, but the effective concentration varied depending on the type of parameter.
Ornamental plants
B. Gholamian Dehkordi; S. Reezi; M. Ghasemi Ghehsareh
Abstract
Introduction Cyclamen persicum is a genus of Primulaceae family and is a winter pot plant that can be marketed within seven months under proper growing conditions. In recent years, the rapid development of lighting technology has increased the use of several types of LED lamps ...
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Introduction Cyclamen persicum is a genus of Primulaceae family and is a winter pot plant that can be marketed within seven months under proper growing conditions. In recent years, the rapid development of lighting technology has increased the use of several types of LED lamps because of their efficient roles to generate visible light via a lot of wavelengths. Application of some plant growth regulators (PGRs) like GA3 is well-known as an environment-friendly growth regulatorwhich is extensively employed to increase the productivity and and changing the phenotypic features of several ornamental plants.Materials and Methods In this experiment, cyclamen large red flower seeds, i.e. the Halios series, were planted in early May, and then kept in a dark and cool greenhouse for one month. After germination and the emergence of cotyledonary leaves, transplants exposed to two levels of the LED light spectrum for 4 months consisting of the ratios of 70:20:10 and 40:40:20 via white:red and blue with the same intensity 100 µmol/m2/s subjected to a 16-hour photoperiodic conditions. At the end of the third month of growth, GA3 was sprayed on the leaves at four concentrations of 0, 20, 40, and 60 mg/l three times around the experiment. NPK fertilizer with a ratio of 10-52-10 was then applied once a week and a ratio of 20-19-19 fertilizer until the roots were fully established. Afterwards, the leaf area was measured using Digimizer version 5.4.3 software, in which the flowering date was calculated from of transferring time the plants of each treatment under light. In the following, chlorophyll and carotenoid contents were measured using Lichtenthaler and Wellburn method. Leaf soluble sugar was measured using the Oregon method and the chlorophyll fluorescence indices were measured using FluorPen FP 100.Results and Discussion According to the results, the highest leaf number of cyclamen seedlings in the treatment of 40:40:20 was equal to seven, whereas the highest leaf area (9.8 cm2) observed under the light treatment of 70:20:10. the blue LED light can affects on differentiation of leaf mesophilic cells as well as the development of intercellular spaces, and the red light affects the production of a plant hormone so-called Meta-Topolin, which stimulates cell division and leaf expansion. Here, it should be noted that adding white LED light to the composition spectrum increases both growth and photosynthesis because of its deeper penetration into the plant canopy. The maximum root length was achieved at a concentration of 60 mg/l GA3 equal to 5.1 cm. It should be mentioned that GA3 is effective to increase the growth of cells in different parts of the plant (such as roots) by stimulating mitotic division. The closest date to cyclamen flowering time (90 days) was obtained in 70:20:10 treatment. . The highest amount of chlorophyll b was achieved from the interaction of light treatment 40:40:20 and concentration of 0 mg/l GA3 equal to 0.35 mg/g. Results showed that the red light is needed for the photosynthesis, whereas the blue light is needed for chlorophyll and chloroplast synthesis, stomatal opening, and photomorphogenesis. The highest amount of leaf soluble sugar of cyclamen seedlings was achieved from the interaction of 40:40:20 and the concentration of 0 mg/l GA3 equal to 0.53 mg/ml. Carbohydrates mostly accumulate in the leaves under blue light, whereas the red light can cause them to accumulate by preventing the transferring the photosynthetic products from the leaves. Among chlorophyll fluorescence indices, the highest VJ index was obtained from 40 mg/l GA3 concentration equal to 0.51. VJ was measured from the first light pulse, in which its increase via increasing the performance of the photosynthetic apparatus reveal the ability of seedlings to make better use of environmental conditions applied to produce more carbohydrates as well as to enhance the growth quality. The highest values of φ-E0 and Ψ-0 indices in GA3 0 treatment were 0.44 and 0.54, respectively, indicating that increasing them improves the performance index of the photosynthetic apparatus. The external GA3 increases only the amount of chlorophyll and soluble protein content in the leaves of some plants, and interferes with the greater light reflection, chlorophyll fluorescence and eventually the performance of photosystem II. In this regard, the highest amount of ABS/RC index was observed in the interaction of 40:40:20 and concentration of 60 mg/l GA3 equal to 2.27, which is equal to increasing the performance index of photosynthetic device. During the plant growth, the use of monochromatic LED light compared to the full visible spectrum or red + blue lights would lead to creating some defects in the electron transport chain.Conclusion An increase in PI (Plant Photosynthetic Performance Index) means that the plant is operating under conditions of normal photosynthesis. In general, an increase in this index indicates the ability of seedlings or mature plants to make better use of environmental conditions to produce more carbohydrates and improve growth quality. The relationship between increasing the amount of chlorophyll b, leaf soluble sugar and ABS / RC index all in 40:40: 20 treatment while confirming this correlation, shows that since most of the light absorption by chlorophyll is in the red and blue light spectrum. 40: 40: 20 is better than 70: 20: 10 with more red and blue light. The effect of light of any quality or GA3 at any concentration on the qualitative traits of seedling or adult plant growth is directly related to plant genotype and no specific effects can be determined for them. The use of complementary LED light may in some respects lead to a further increase in the quality of Cyclamen seedlings, but it is only reasonable to use them if it compensates for other production costs, including electricity consumption. Finally, chlorophyll fluorescence indices are also independent of each other in terms of their effect on the performance of the photosynthetic apparatus.
Ornamental plants
T. Oraee; Mahmoud Shour; A. Tehranifar; S.H. Nemati
Abstract
Introduction: The Hollyhock (Alcea rosea) is a summer flowering biennial plant that is native to China and belongs to the Malvaceae family. It is one of the most valuable ornamental plants, whose 36 species are cultivated in Iran. It is an increasing garden escape, especially in urban areas, and is usually ...
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Introduction: The Hollyhock (Alcea rosea) is a summer flowering biennial plant that is native to China and belongs to the Malvaceae family. It is one of the most valuable ornamental plants, whose 36 species are cultivated in Iran. It is an increasing garden escape, especially in urban areas, and is usually found at foot of walls, in ruderal areas, and in cracks of pavements and old walls. Also, it is sometimes seen on riverbanks (for instance on dikes of the river Maas), dumps or road- and railway banks. Alcea rosea has been used as an herbal plant in folk medicine for treatment of different diseases such as common cold and cough. This plant is antiphlogistic, astringent, demulcent, diuretic and expectorant. Drought is the most significant environmental stress in agriculture worldwide, and improving yield under drought is a major goal of plant breeding. Seed germination and early seedling growth are potentially the most critical stages for water stress. When subjected to drought stress, plant metabolism is interrupted or inhibited by increasing reactive oxygen species (ROS) and lipid peroxidation, resulting in reduced germination, weaker root and shoot growth and even mortality. Plants have evolved oxygen-scavenging systems consisting of non-enzyme antioxidant metabolites, such as proline and various antioxidant enzymes including superoxide dismutase, peroxidase and catalase.Materials and Methods: In order to examine the effect of drought stress on germination indexes, various antioxidant enzyme changes and non-enzyme antioxidant metabolites in Alcea rosea, an experiment was conducted in complete randomized design with three replications. The drought stress treatment was conducted in five levels with osmotic pressures 0, -2, -4, -6, and -8 bar and with using PEG (Poly Ethylene Glycol 6000) on two ecotypes of Alcea rosea (ecotype 1= Mashhad and ecotype 2= Tehran). The seeds are at first sterilized with hypo chloride sodium for two minutes and then washed superficially three times with distilled water. 25 seeds were transferred to a glass petri dish with 10 cm diameter, and for the duration of the experiment, 5 ml solution with different levels was added to each petri dish. After 14 days at 25±1 ºC temperature, the number of geminated seeds in each day was counted and recorded. In the first part of the experiment, after the end of the germination period, the following growth parameters were measured: germination percentage, germination rate, root and shoot length, and the fresh weight of seedling. In the second part, the activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), malondialdehyde content, lipid peroxidation in terms of malondialdehyde (MDA) content, and proline index were measured.Results and Discussion: The ecotype, drought treatments and their interaction had significant effects on growth parameters (germination percentage, germination rate, radicle and plumule length, and seedling fresh weight), as well as physiological and biochemical parameters (SOD, POD, CAT, MDA and proline). The highest germination parameters were recorded at Mashhad ecotype. Germination percentage and germination rate were severely affected by drought. Maximum percentage of germination (36) was recorded at control group followed by 32.1 at -2 bar and -4 bar PEG treatments in ecotype 1. Germination percentage in two ecotypes further declined to 33% at -8 bar compared to the control treatment. In both ecotypes, plants had the highest germination rate in control media (zero osmotic potential) but germination rate decreased significantly by decreasing water potential. Germination rate of control seeds of ecotype 1 was 11.7, while that of ecotype 2 was 8. 3. Germination rate in two ecotypes further declined to 56% and 38 %, at -8 bar compared to the control treatment, respectively. Ecotype 2 displayed a significant reduction in radicle and plumule length compared to the ecotype 1. Generally, the radicle and plumule length decreased significantly in relation to the drought stress caused by PEG. Ecotype 2 in -8 bar PEG treatment had the highest (41 and 32%) decrease in radicle and plumule length compared to the control temperature. In two ecotypes (Mashhad and Tehran) of Alcea rosea, increasing PEG concentrations resulted in a decrease in fresh and dry weights. Water absorption is the first germination stage. Due to the probable resistance of the ecotype one, water absorption rate is higher, and as a result, the percentage and rate of germination have increased. Ecotype 1 exhibited higher leaf SOD activities in response to -2 bar compared to -8 bar, but the SOD activities in ecotype 2 showed a general increase trend with increases in the PEG concentration. Drought stress resulted in lower antioxidant enzyme activities (POD) in leaves of both ecotypes compared to that observed at the control treatment, but the activity of CAT increased with the increase of drought stress. In both ecotypes, exposure to -8 bar resulted in significantly higher leaf MDA activities. Plants exhibited higher proline in response to -8 bar treatment compared to the control. By increasing the PEG concentration from control to -8 bar, proline content increased about 90 percent. In this experiment, drought stress reduced the rate and germination percentage and delayed subsequent plant deployment. When plants are subjected to drought stress, their metabolism is interrupted or inhibited by increasing reactive oxygen species (ROS) and lipid peroxidation, resulting in reduced germination, weaker root and shoot growth and even mortality. The recent experiment showed that the activity of two superoxide dismutase and peroxidase enzymes decreased with increasing drought stress, and the activity of the catalase enzyme increased; this is in agreement with the results reported by other studies. On one hand, the increase in the activity of the catalase enzyme indicates that it is perhaps the most important enzyme involved under drought condition, which increased over the course of 14 days. On the other hand, limiting the activity of enzymes and increasing the amount of proline showed that increasing the resistance to drought stress in the plant depends on the accumulation of contaminating substances such as proline.Conclusion: Due to the higher resistance of the ecotype 1 and increase in water absorption, the percentage and rate of germination were increased. If water absorption is disturbed by the seed, the germination activity is slowly applied and the later growth of the roots will decrease the germination rate. Therefore, it seems that Mashhad ecotype with increase of catalase and proline has the highest drought tolerance compared to the other ecotype at germination stage. There was a significant correlation between germination percentage with SOD and POD.
Ornamental plants
S. Heidari; S. Reezi; S.N. Mortazavi; ali nikbakht
Abstract
Introduction: Lily (Lilium spp.) is one of the most beautiful and popular ornamental bulbous plants that belongs to the Liliaceae family. Lilies (Lilium spp.) belong to one of the six more important genera of bulbous flowers, which is the fourth most famous plant in the world after Rose, Dianthus, and ...
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Introduction: Lily (Lilium spp.) is one of the most beautiful and popular ornamental bulbous plants that belongs to the Liliaceae family. Lilies (Lilium spp.) belong to one of the six more important genera of bulbous flowers, which is the fourth most famous plant in the world after Rose, Dianthus, and Chrysanthemum. The genus Lilium comprises more than 100 species, which are mainly distributed in the northern hemisphere. These species are taxonomically divided into seven sections, including Martagon, Pseudolirium, Lilium, Archelirion, Sinomartagon, Leucolirion, and Oxypetalum. It has been suggested that early removal of Lily buds should enhance Lily bulb yield. Disbudding improves the process of bulb development through its influence on the accumulation and transport of carbohydrates in Lily bulbs. In several studies, the effect of bud removal on vegetative characteristics and propagation of Lily bulbs including cut flower length, leaf area, size and weight of the bulb, number, and size of bulbs, number, and size of scales have been reported. With considering the importance of Lily bulb production in the country and the lack of current research on new Lilium hybrids, including various Oriental and OT hybrids, this study was conducted to investigate the effect of cultivar and disbudding on the vegetative characteristics of Lily flowers and its effect on production and multiplication of Lily. Materials and Methods: To study the effect of cultivar and disbudding on the growth and bulb production of Lily, a factorial experiment in a completely randomized design with two cultivars (the Tiber and Donato), and three disbudding items (D0= No disbudding, D1= Disbudding at the stage of bud appearance, and D3= Disbudding at the stage of 3 cm bud length) was conducted in three replications. This research was carried out in hydroponic greenhouses in Dehaghan city, Isfahan province, in an area with a longitude of 51˚, 61´ E, 31˚, 96´ N, and 2004 m mean above sea level. Temperature, humidity, and light intensity inside the greenhouse during the growing period was 15-25 ℃, 50-70 percent, and 20-30 kilolux, respectively. Evaluated characteristics included the plant height, stem diameter, number of leaves, leaf area, number of buds, bulb weight, number of the scale, scale size, number of bulblets, and propagation coefficient. Results and Discussion: The results showed that cultivar and disbudding (Except stem diameter) significantly affect all evaluated traits, while their interaction had a significant impact on bulb weight, bulblet number, propagation coefficient, bulb size, and scale size. In the Donato cultivar, plant height, stem diameter, leaf area, bulb weight, bulb size, scale size, number of bulbs, and propagation coefficient were 32.9%, 6.9%, 35.3%, 40.9%, 14.2%, 70.1%, 77.9%, and 8.2%, respectively higher than Tiber cultivar, while in the Tiber cultivar, the number of leaves and number of scales was 12.5% and 54.9%, respectively higher than the Donato cultivar. The highest plant height and leaf area were observed in non-disbudding treatment. However, the shortest stem and the smallest leaf were observed in disbudding at the stage of bud appearance and disbudding at the stage of 3 cm bud length which was 10.1% and 9.4%, respectively less than the non-disbudding treatment. By disbudding at the stage of bud appearance, the maximum number of scales, the heaviest bulb, the largest bulb, and the maximum scale size was measured that increased by 11.3%, 91.2%, 23.3%, and 39.2%, respectively compared to the non-disbudding treatment, while the lowest value of mentioned traits was recorded with non-disbudding treatment. By applying bud removal treatments up to the third level, the number of leaves, the number of bulbs, and propagation coefficient increased by 2.7%, 37.0%, and 3.6%, respectively, compared to the non-disbudding treatment, although there was no statistically significant difference between disbudding at the stage of 3 cm and disbudding at the stage of bud appearance. On the other hand, the lowest value of these traits occurred in the non-disbudding treatment. In the Tiber cultivar, the highest bulb weight, bulb size, and scale size were obtained by disbudding at the stage of bud appearance, which showed an increase of 93.5%, 24.0%, and 53.9%, respectively, compared to the non-disbudding treatment. Furthermore, in the Donato cultivar, disbudding at the stage of bud appearance significantly increased bulb weight, bulb size, and scale size by 89.4%, 22.8%, and 31.5%, respectively, compared to the non-disbudding. Also, the highest bulblet number and propagation coefficient in this cultivar were obtained by disbudding at the stage of 3 cm bud length, which increased 58.3% and 0.7%, respectively compared to the non-disbudding treatment. Conclusion: In general, it can be concluded that the Donato cultivar has a significant advantage in most of the evaluated traits over the Tiber cultivar, which can be attributed to the genetic distance between different Oriental and OT hybrids. Disbudding at the stage of bud appearance, if the end of the branch is not damaged, was the most appropriate treatment for replanting, production, and propagating of Lily bulb.
