Ornamental plants
Mohadeseh Piri; Zohreh 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.
Seyyedeh Mahdiyeh Kharrazi; Ahmad Sharifi; Saba Nejatizadeh; Azadeh Khadem; Maryam Moradian
Abstract
Introduction: Considering the occurrence of successive droughts in our country and the necessity of optimal water consumption, the use of modern technologies such as closed systems to increase the efficiency of fertilizer and water use will have an effective role in reducing production costs and increasing ...
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Introduction: Considering the occurrence of successive droughts in our country and the necessity of optimal water consumption, the use of modern technologies such as closed systems to increase the efficiency of fertilizer and water use will have an effective role in reducing production costs and increasing yield. The Nutrient Film Technique (NFT) system is one of the hydroponic culture systems in which the nutrient solution is circulated continuously. In this system, a thin layer of nutrient solution will be available to the plant roots, which has a significant effect on reducing fertilizer and water consumption.
Materials and Methods: The present study was conducted to select an optimal system for cultivation of Gerbera plantlets. Plantlets were cultivated in different systems after the acclimation stage: Integrated bedding system as a closed system containing different culture media (Perlite, vermiculite, vermiculite: perlite, cocopeat: perlite and rock wool) and NFT hydroponic system as a closed system. For fertilization, the following fertilizer combination (mM) was used: K2SO4 (0.22), KNO3 (3.62), KH2PO4 (0.71), NH4H2PO4 (0.35), NH4NO3 (0.53), Ca (NO3)2,4H2O (1.48), MgSO4, 7H2O (0.4), MnCl2, 4H2O (0.0049), H3BO3 (0.020), ZnSO4 (0.0061), CuSO4, 5H2O (0.00048), NaMoO4, 2H2O (0.00058), FeSO4, 7H2O (0.0348), Na2EDTA (0.0384). The experiment was conducted in a completely randomized design with six treatments in six replicates. During six months, the growth parameters of the plants including number of leaves, petiole length, fresh and dry shoot weight, leaf chlorosis percentage, leaf necrosis percentage, flower number, flower diameter, flowering stem height, number of days to flowering, end diameter of the stalk and the middle diameter of the stalk were evaluated. Data preparation was done in Excel and data analysis was performed using the Jump 8 software. Mean comparison between treatments was performed with LSD test at 5% probability level and charts were drawn using the Excel program.
Results and Discussion: The results showed that there was a significant difference between treatments for the number of leaves (p <0.01). Seedlings cultivated in the vermiculite culture medium produced the highest number of leaves; however, there was no significant difference between seedlings cultured in vermiculite and vermiculite: perlite media. The lowest number of produced leaves was observed in plantlets grown in the NFT system. Also, the seedlings grown in the rock wool medium had no significant difference with the NFT system. In this regard, the drought stress on plants and the consequent poor growth of plantlets reduced the number of produced leaves. The percentage of necrotic leaves in the NFT system was more than twice the vermiculite culture medium. There was no significant difference between cocopeat: perlite, perlite, rock wool, and NFT systems. Also, the lowest amount of necrotic leaves was found in the vermiculite culture medium, which did not have a significant difference with vermiculite: perlite culture medium. Low levels of leaf necrosis in these treatments indicate the optimal absorption of nutrients and the proper growth of plantlets in these culture media. The results showed that plantlets cultivated in the vermiculite and vermiculite: perlite flowered more quickly than other culture media and also produced more flowers. Plantlets grown in the rock wool medium did not show the desirable performance, which is due to drought stress. Besides, the use of cocopeat in the culture medium did not have a beneficial effect on plants. Measuring the initial electrical conductivity in the cocopeat culture medium also indicates a high EC concentration in this culture medium, which could affect the growth parameters of the plant and lead to poor vegetative growth of plantlets. Since Gerbera plant has bulky roots, the roots of this plant cannot be developed well in the NFT system, so the use of the NFT system is not suitable for Gerbera cultivation. The best performance of plant samples was obtained from vermiculite culture media, but since there were no significant differences between vermiculite and vermiculite: perlite, so to reduce production costs, the use of vermiculite: perlite culture medium in the closed system is recommended for the cultivation of Gerbera plant.
Conclusion: Since Gerbera plant has bulky roots, the roots of this plant cannot be developed well in the NFT system, so the use of the NFT system is not suitable for Gerbera cultivation. The best performance of plant samples was obtained from vermiculite culture media, but since there were no significant differences between vermiculite and vermiculite: perlite, so to reduce production costs, the use of vermiculite: perlite culture medium in the closed system is recommended for the cultivation of Gerbera plant.
Ali Naseri Moghadam; Hassan Bayat; Mohammad Hossein Aminifard; Farid Moradinezhad
Abstract
Introduction: Salinity and drought have adverse impacts on crop production throughout the world, especially in arid and semiarid areas. Salinity decreases crop growth and yield through modifications of ion balance, water status, stomatal behavior, photosynthetic efficiency, salinity-induced nutrient ...
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Introduction: Salinity and drought have adverse impacts on crop production throughout the world, especially in arid and semiarid areas. Salinity decreases crop growth and yield through modifications of ion balance, water status, stomatal behavior, photosynthetic efficiency, salinity-induced nutrient deficiency and changes to the soil structure. Drought is another one of the main factors limiting the growth and development through the anatomical, morphological, and physiological and biochemical changes that the severity of drought damage varies depending on the duration of the stress and plant growth stage. Water stress reduces relative water content, photosynthesis pigments, stomatal conductance, biomass, growth and ultimately plant performance. Narcissus (Narcissus tazetta L. cv. ‘Shahla’) belongs to the Amaryllidaceae family is grown as a cut flower, landscape and medicinal plant that grows throughout the world except tropical regions. It is necessary to know the tolerance of N. tazzeta to drought and salinity stress in order to produce optimal product. According to previous studies, no complete research has been done on the effects of drought and salinity stress on N. tazzeta. Therefore, the present study was carried out with the aim of investigating the combined effects of drought and salinity stress on growth, flowering and biochemical characteristics of N. tazzeta.
Materials and Methods: This research was carried out in Faculty of Agriculture, University of Birjand, in 2017. A pot experiment was conducted in completely randomized deign with factorial arrangement and three replications. The treatments included sodium chloride (NaCl) in four levels 0 (control), 20, 40 and 60 mM and drought stress in four levels 30, 50, 70 and 90% of field capacity. The plants were harvested four months after the start of salt and drought treatments. The investigation traits were included vegetative, reproductive and biochemical characterizes. Measured traits were included root length, volume of root, root fresh weight, bulb length, bulb fresh weight, shoot fresh weight, total dry weight, flower diameter, flower crown diameter, stem diameter, days from planting to flowering, days from flowering to senescence, antioxidant activity, total phenolic content and total soluble sugar of leaf and root. The data were analyzed by SAS version 9.4 and the means separated by Duncan's multiple range test at p < 0.05. Excel was used to draw graphs.
Results and Discussion: The results of simple effects showed that drought and salinity stresses decreased the values of flowering stem diameter, flower diameter, root length, root volume, root fresh weight, bulb fresh weight, bulb length, shoot fresh weight, total dry weight and days from flowering to senescence. In contrast, the values of the number of days from sowing to flowering, total soluble sugars of leaf and root, antioxidant activity and total phenolic content increased under the influence of these two stresses. The results of interaction effects showed that the destructive effects of salinity and drought stress were intensified in co-application conditions, so that the lowest values of growth and reproductive traits were observed in the most severe stress (30% field capacity × 60 mM salinity). Usually, root and shoot length in sodium chloride solution is reduced due to the toxicity of ions and their negative effects on cell membranes. Drought stress and salinity reduce cell division and also reduce the size of cells and consequently the length of the plant decreases. Delay in flowering is due to multiple stresses (osmotic imbalance, nutrient insufficiency and cellular toxicity) that is caused by salinity and drought stresses. These stresses produce ROS compounds that damage the proteins, lipids, carbohydrates, and nucleic acids. Plants for scavenging and detoxifying these compounds from the cell surface use enzymatic (catalase, superoxide dismutase, etc.) and non-enzymatic (phenolic compounds and carotenoids) defense systems that increase the antioxidant activity of the plant.
Conclusion: The results of this study showed that drought and salinity stresses had negative effects on growth and flowering traits, which was exacerbated by the combined application of these two stresses. On the other hand, the highest levels of antioxidant activity, total phenolic content and total soluble sugars were obtained under severe stress conditions (drought or salinity). Salinity and drought stress reduced the flowering rate, quality of flowers and the flower life on the plant, but all the levels of stress reached to flowering stage. Also, the growth of narcissus plant was not affected by the highest levels of drought (30% crop capacity) and salinity (60 mM) stress. In general, the results showed that both drought and salinity stress reduced the growth and yield of narcissus flower, but the destructive effects of salinity stress on the growth, ornamental and physiological traits of narcissus flower were more than drought stress.
