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.
Azam Ranjbar; Noorollah Ahmadi
Abstract
Introduction: Miniature rose (Rosa hybrida) are well known as one of the world’s most popular ornamental plants cultivated worldwide as potted and/or bed plants. Nowadays, more than 100 million pots of miniature roses are propagated by stem cutting in the commercial greenhouses of European countries ...
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Introduction: Miniature rose (Rosa hybrida) are well known as one of the world’s most popular ornamental plants cultivated worldwide as potted and/or bed plants. Nowadays, more than 100 million pots of miniature roses are propagated by stem cutting in the commercial greenhouses of European countries such as Denmark and Germany. Some treatments such as application of plant growth regulators and suitable rooting medium could be required for accelerating root formation in rose cuttings. Using plant growth regulators like natural or synthetic auxin is a pre-requirement for the initiation of adventitious root in some stem cuttings and it has been reported that the division of the first initiator cells of root depends on internal or synthetic auxin. Methods of application of these chemicals and suitable concentration could be related to several factors, importantly the plant varieties, type of cuttings and the time of cutting preparation. Various kinds of media such as soil, peat moss, perlite and vermiculite are used as bed substrate according to required ratio. Rooting media must provide appropriate moisture and air ventilation for cuttings establishment, which highly affect the cuttings root formation. Appropriate procedure for using wastes materials as culture bed, especially those materials that produced locally, is main aim of some studies to find an alternative medium in ornamental pot plant production. In this regards, evaluation of agricultural wastes to be used to culture bed and introducing suitable materials could be considered. Accordingly, the objective of the present study was to determine the effects of two types of plant growth regulators and bed combinations on rooting percentage of semi-hardwood cuttings in miniature rose.
Materials and Methods: In order to evaluate the effects of different concentrations of indolebutyric acid (IBA) and naphtaleneacetic acid (NAA), and two media with different composition on root formation of miniature rose stem cutting, this research was carried out as a factorial on the basis of randomized complete design (RCD) with three replications. Plant growth regulators including IBA at concentrations of 0, 1000, 2000 and 3000 mgl-1, concentrations of NAA at 0, 500, 1000, 1500 and 2000 mgl-1 were applied together with two types of rooting media. Media including mixing volume of perlite, tea waste compost and sand in a ratio of 1: 2: 2, and perlite, peat and sand in a ratio of 1:2:2 were mixed and applied in this experiment. Using SAS software, data was analyzed based on a generalized linear model (GLM) analysis and tested by least significant difference (LSD) at (P-value< 0.05).
Results and Discussion: Results showed that the highest rooting percentage of cuttings was obtained with 2000 mgl-1 of IBA, while no significant effect of NAA treatment and different rooting media on percentage of rooting was revealed. The two-fold and three-fold interaction of treatments on other measured traits such as primary and secondary root number and root diameter were significant. The two-fold interaction of NAA treatments and rooting media on the trait of primary root number were no significant. The highest root number and root diameter measured in medium containing perlite, tea waste compost and sand in a ratio of 1:2:2 for cutting received combined plant growth regulators.
Conclusions: Compost, the final product of organic residues degradation, improves soil physical characteristics such as soil aggregate formation and stability, water penetration, porosity, compressing resistance and nutrients availability. As well, it improves soil biological characteristics and in result, integration of compost with soil can increase growth, yield and quality of crop. There are also some evidences that in contrast of peat, compost contains plant growth regulators improved plant growth and development. Totally, considering our obtained results, in order to accelerate rooting formation in miniature rose cuttings, treatment of cuttings with synthetic plant growth regulators in medium containing perlite: tea wastes compost: sand (2:2:1) under alternate mist system is recommended. Organic materials activate root area as well as improving fertility of soil. They also play a role in supplying and releasing absorbable nutrients, root establishment, enhancing field capacity, reducing evaporation from soil surface and reducing expenses. Therefore, we emphasize on appropriate using of these components in order to obtain better productivity.
Moslem Salehi; Vahid Reza Saffari; Shima Hasanzadeh Fard
Abstract
Introduction: Bedding plants, especially petunia is important element for urban landscaping and attracted the attention of landscapers. This is due to some properties such as growth habit and color. The petunia (Petunia hybrida L.) belongs to Solanaceae family that has annual and perennial varieties. ...
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Introduction: Bedding plants, especially petunia is important element for urban landscaping and attracted the attention of landscapers. This is due to some properties such as growth habit and color. The petunia (Petunia hybrida L.) belongs to Solanaceae family that has annual and perennial varieties. This plant is originally from Argentina, Brazil and Uruguay. Some plant growth regulators such as gibberellic acid (GA3) and vitamins including thiamine and ascorbic acid affect plant growth and development and may extend flowering period. Vitamin C affects cell division and cell growth in plants and is effective on the feeding cycle activity in higher plants and it has an important role in electron transport system. The concentrations of 50 and 100 ppm of vitamin C and thiamine can increase the plant height, leaf number, leaf area, fresh and dry weight, and chemical compounds of the Syngonium plant. The application of 100 mg/l of GA3 significantly increased plant height and the number of leaves of gladiolus.
Material and methods: The experiment was arranged in a factorial based on a completely randomized design with five replications. In this research, growth characteristics (lateral branch number, flower number, flower diameter, stem diameter, root length, and lateral branch length) and biochemical characteristics (chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, and reducing sugar) were measured. After seeding and transplanting the seedling at 6 leaf stage, plants sprayed at 4 various growth stages with following treatments:
1- Control
2- Vitamin C(100 mg/l)
3- Thiamin (100 mg/l)
4- Gibberellic acid (100 mg/l)
5- Vitamin C and Thiamin (The concentration of both 100 mg/l)
6- Vitamin C and Gibberellic acid (The concentration of both 100 mg/l)
7- Thiamin and Gibberellic acid (The concentration of both 100 mg/l)
8- Vitamin C, Thiamin and Gibberellic acid (The concentration of three 100 mg/l)
Data obtained from the measured parameters analyzed using statistical package SAS and means were compared using LSD test at the level of statistical significance of P˂0.05.
Results and Discussion: The results indicated that GA3 affected all the measured characteristics except carotenoids in comparison with thiamine and ascorbic acid. Meanwhile, the combined application of GA3 and ascorbic acid affected stem growth, root growth and flower diameter. Simultaneous use of GA3 and thiamine was effective on pigments, reducing sugar, carotenoids and flower number. The simultaneous application of three chemicals resulted in a considerable increase in growth and development traits, such as stem and root growth, flower number and diameter, pigments and reducing sugar compared to control. Generally, gibberellic acid will increase vegetative growth with impress cellular processes, including stimulation cell division and cell elongation. It was reported that the uses of ascorbic acid and gibberellic acid in Thyme (Thymus vulgaris) increased plant height and root length. Ascorbic acid makes a set of functions such as cell division and enlargements, cell wall development and other developmental processes in plants. Ascorbic acid affects plasma membrane proton pump and according to the acidic theory stimulates weaking cell wall and consequently will increase cell wall development and cell enlargement. It was found that thiamine significantly increased flower number in chrysanthemum .
Conclusion: The results indicated that the synergistic effects of this material can be used to enhance the growth and development of petunia. On the other hand, in arid and semiarid areas of the country, that drought and salinity stresses somewhat inevitable, these materials, especially vitamins are effective in reducing stress and increase flowering period.
