جستجوی مقالات مرتبط با کلیدواژه "ژربرا" در نشریات گروه "باغبانی"

The cut flower industry is economically important across the world. Gerbera (Gerbera jamesonii Bolus) is one of the most popular cut flowers in Iran and worldwide and the improvement of its postharvest life is very important. Stem bending during the early stage of vase life is a critical problem in many cultivars of this flower. In this research, silicon as an antioxidant compound was used at 500 and 1000 micromolar concentrations, and the effects on some oxidative characteristics, antioxidant enzyme activity, phenylalanine ammonia-lyase (PAL), and polyphenol oxidase activity in three colors (Rosalin, Stanza, and Apollo) of cut gerbera flower were investigated. Histological studies also were performed by hand sections and light microscopy. Silicon application prolonged the vase life in all three cultivars of gerbera. The lowest vase life (6 days) was measured in the control treatment and the highest vase life (17.33 days) was gained in Rosalin using 1000 µM silicon.  Meanwhile, a significant increase in the activity of antioxidant enzymes and PAL was detected, while polyphenol oxidase (PPO) activity and lipid peroxidation were significantly decreased. It seems that silicon improved the quality of gerbera cut flowers by scavenging free radical oxygen, preserving cell membrane integrity, decreasing PPO activity, and increasing the vascular and supporting tissue.

In order to investigate the effects of humic acid and mycorrhiza on gerbera cv. Dune, an experiment was performed as a completely randomized design with two factors and three replications in hydroponic conditions. First factor included humic acid at 4 concentrations (0, 500, 1000, and 2000 mg L-1 as media drench). The second factor contained two levels of mycorrhizal fungi (with and without mycorrhiza at root zone). Attributes such as leaf number, rosette diameter, root fresh and dry weight, flower diameter, flower stalk diameter and number, time from bud emergence to anthesis, total phenol content, colonization percent and the activity of ascorbate peroxidase and hydrogen peroxide were measured. The results showed that humic acid and mycorrhizal fungi treatments led to increase in the leaf number, rosette diameter, fresh and dry weight of roots and antioxidant enzymes activity and decreased the time from bud emergence to anthesis comparing untreated plants. Phenol content was significantly increased compared to control plants by application of 1000 and 2000 mg L-1 of humic acid plus mycorrhizal fungi. The combined use of humic acid and mycorrhiza was effective to improve some morphological and physiological properties of gerbera and the concentration of 1000 mg L-1 humic acid plus mycorrhiza application were the most effective treatment.

Gerbera is one of the most famous cut flowers, considered as one of the top ten cuts in the floriculture industry. Nutrient recipe management is one of the key factors in greenhouse crops production The correct amount and ratio of nutrients with each other in nutrient solutions is influenced by some production and absorption conditions such as light intensity, ambient temperature and type of culture medium, among which the ratio of some high-consumption elements such as potassium and nitrogen is significant. In order to investigate the effect of different ratios of potassium to nitrogen on yield and some quantitative and qualitative characteristics of gerbera flower of Dune cultivar, a study in a completely randomized design with four treatments of potassium to nitrogen fertilizer ratio (1.25 to 1, 1.5 To 1, 1.75 to 1 and 2 to 1) were performed with three replications and five observations. Results showed that increasing the ratios of potassium to nitrogen improved growth and flowering and had a significant effect at the 1% level on the number of leaves, leaf fresh and dry weight, flower number, flower stem height, flower stem fresh weight, chlorophyll index and soluble sugars content. A significant effect at the 5% level also observed in flower vase life and petal anthocyanin. In general, with regarding the costs of greenhouse crops production and results of the present study, the application of 1.75:1 ratio of potassium to nitrogen in comparison with others ratios of potassium to nitrogen is recommendable and have more positive effects on the quantitative and qualitative characteristics of gerbera cv. Dune.

In order to maintain the postharvest quality and vase life of the "Stanza" cultivar of gerbera cut flowers, an experiment was designed as split-plot for time based on a completely randomized design, with four replications, at 2018 in horticulture department of Ilam university. The treatments consisted of preharvest application of Spermine 2 mM and γ-Aminobutyric acid 2mM (GABA), as sub-plot, at two stages (2T) of spraying (the stage of emergence of flower branch and 10 days later) and three stages (3T) of spraying (the stage of emergence of flower branch, 7 and 10 days later) that investigated, as the main plot, at 0, 3, 6 and 9 days postharvest at 22±1 °C and relative humidity of 65 to 70%. The results showed that, respectively, spermine 3T, spermine 2T, GABA 3T and GABA 2T treatments increased vase life and maintaind postharvest quality of Gerbera cut flowers compared to the control. The results of the 9th day showed that the highest fresh weight, absorption of vase solution (VSU), soluble solids, protein, phenol and total flavonoid, activity of the catalase (CAT), guaiacol peroxidase (GPX), superoxide dismutase (SOD) and Phenylalanine ammonia lyase (PAL), as well as the lowest ion leakage (EL), malondialdehyde MDA and polyphenol oxidase (PPO) activity respectively were observed in Spermine and GABA treatments, and in some of the studied traits, there was no significant difference between two and three stages of spraying. Therefore, the use of spermine 3T as the best treatment in present study is recommended as an application method to increase the vase life of "Stanza" cultivar of gerbera cut flowers.

Gerbera is one of the most important cut flowers in the world and belongs to the Asteraceae family. Due to its diverse and adaptable species for growth with a wide range of climatic conditions, this flower has become a profitable cut flower for growers. Polyamines in plant tissues act as a potent factor in preventing the production of ethylene. Polyamines and ethylene have antagonistic effects (anti-aging and aging effects), so that the balance of these two hormonal groups in plants is very important for plant tissues. The balance between the two opposing regulators leads to a delay or acceleration in the aging process. Mycorrhizal fungi can be useful in hydroponic greenhouse systems, which increase the amount of CO2 in greenhouses by increasing photosynthesis in plants, as well as CO2 emissions in the control environment, which both optimally manage the environment and increase the yield and quality of plant products. Due to the economic importance of cut flowers, it seems necessary to provide treatments (such as the use of putrescine and mycorrhiza) to increase the quality and longevity of this plant. 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. This study was performed as a factorial experiment in a completely randomized design with three replications, each replication consistedd of three pots and each pot contained a plant. The factors of this experiment were Mycorrhizal fungi inoculation (with and without inoculation) during the transplanting process to the culture medium near the roots, and putrescine at four concentrations of 0 (control), 1, 2, and 4 mM, were applied two weeks after transplantation, every 15 day-interval for three months. In order to investigate the effects of putrescine and mycorrhizal fungi on some morphological and physiological characteristics of plants, two weeks after the end of treatments, leaf sampling was performed to measure physiological characteristics. Effects of putrescine and mycorrhizal fungi were assayed in some morphological characteristics including leaf number, leaf length and leaf area, fresh and dry weight of leaves and some physiological parameters including chlorophyll index, chlorophyll content (a, b and total) and soluble sugar as well as vase life and petal’s anthocyanin during postharvest time. The SAS software version 9.1 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%. Excel (2016) software was also used to draw the graph. According to the comparison of means, putrescine, along with mycorrhizal fungi, increased the number of leaves, leaf area, and the fresh and dry weight of the leaves as well as chlorophyll index, chlorophyll a, b and total and carotenoid content of leaves. In this study, inoculation with mycorrhiza reduced leaf length but increased leaf area resulted in that mycorrhiza could increase leaf blade because of increasing cytokinin in plant. Putrescine with mycorrhizal fungi, increased leaf growth, photosynthesis of plant and carbohydrates production. In the literatures, it is reported that, the vase life of cut flowers is a very important point in choosing them as great cut flowers. The results showed, putrescine and mycorrhiza had increased the vase life of gerbera flowers, therefore increased the quality of this plant. Putrescine and mycorrhiza also increased the amounts of anthocyanins in the petals, and by the sixth day, the highest levels of anthocyanins were observed in the petals. Probably, the reason for increasing the anthocyanins on the sixth day is the presence of carbohydrates stored in the flower, which due to the reduced respiration and carbohydrate consumption in this process. Based on the results of the present study, it can be concluded that putrescine, with mycorrhizae, improved growth characteristics as well as increasing the postharvest life and the quality of cut flowers of gerbera. It is also observed that among the different concentrations of putrescine, the concentration of 2 mM had the greatest effect on the growth and physiological parameters as well as vase life of gerbera.

In order to investigate the interaction effects of humic acid and nano-calcium chelate on Gerbera jamesonii cv. Dune, an experiment was performed as factorial based on a completely randomized design with two factors and three replications in hydroponic conditions. First factor was included: humic acid in 4 concentrations of 0 (control), 500, 1000, and 2000 mg L-1 as drench and the second factor: nano-calcium chelate at 4 concentrations of 0 (control), 1, 2, and 3 g L-1 as foliar application. Indices such as number of leaves and leaf area, fresh and dry weight of inflorescence, vase life, time of bud to floral anthesis, flower longevity, and antioxidant enzymes activity were measured. Results showed that humic acid and nano-calcium chelate in comparison with the control increased the activity of antioxidant enzymes such as catalase, ascorbate peroxidase, and guayacol peroxidase about 7, 6, and 7 times, respectively. Vase life and flower longevity were affected by application of humic acid and nano-calcium chelate compared to the control as showed a 57 and 31% increasing, respectively. Flower diameter and flower stem diameter showed 20% increasing compared to control. With increasing the concentration of nano-calcium chelate, leaf area increased. The number of leaf was increased only with increasing the concentration of humic acid. Generally, application of both humic acid and nano-calcium chelate was effective on improving some characteristics of gerbera and approximately 2000 mg L-1 humic acid and 2 g L-1 nano-calcium chelate were more effective.

This experiment was performed to evaluate the effect of different nitrogen forms (ammonium to nitrate ratio) on the growth and flowering characteristics of two gerbera cultivars (‘Stanza’ and ‘Double Dutch’). The aim was to recommend the appropriate amount of NH4+:NO3¯ ratio in the nutrient solution to optimize quantity and quality characteristics in gerbera. This experiment was conducted in a completely randomized factorial design with two factors including NH4+:NO3¯ ratios and cultivar type with three replications. The NH4+:NO3¯ ratios (0:100, 20:80, 40:60, and 60:40) were supplied as a first factor and second factor was gerbera cultivars (‘Stanza’ and ‘Double Dutch’). The results indicated that increasing ammonium concentration in the nutrient solution to more than 40% of total N, significantly reduced growth indices and gerbera flower numbers compared to NH4+:NO3¯ ratio of 20 to 80. Results showed that the highest flower number (314 flowers m-2 year-1), stalk dry weight (5.2 g), flower stalk diameter (0.92 cm), flower stalk weight (2.31 Kg) and vase life (14 days) were obtained in 80:20 of NH4+:NO3¯ ratio. Thereofre, nutrient solution with NH4+:NO3¯ ratio of 20:80 is an appropriate solution recommended for commercial production of gerbera cut flowers in order to achieve the optimum quantity and quality yield of Cut Gerbera.

A major problem associated with cut Gerbera flowers is short postharvest life that resulted in rapid stem bending. The main objective of the present study was to investigate the effect of lignin biosynthesis inhibitors as vase solutions on the vase life of Gerbera (Gerbera jamesonii cv. Danish). Gerbera cut flowers were treated with chemical inhibitors include EDTA (5, 10 and 15mM), NaF (0.06, 0.08 and 0.1mM) and NaN3 (0.05, 0.1 and 0.2mM). Cut stems were placed in these solutions for 20 h at 20°C (Pulse treatment). Results showed that sodium fluoride at 0.06 mM and sodium azide at 0.2mM were more effective in increasing vase life of cut flowers (14 days) than other treatments. Tip burning in ray florets was found at the highest concentration tested of sodium fluoride (0.1mM). Also, sodium azide at 0.2mM showed significant (P<0.01) positive effects on maintenance of fresh weight (51.8%), water uptake (49.81%), flower diameter (44.94%) and anthocyanin content (61.8%) compared to control. In contrast, longevity of cut gerbera was not increased with EDTA treatment. The data showed that EDTA caused high toxicity and hastened the time to bending of stem. Therefore, lignin biosynthesis inhibitors such as sodium azide and sodium fluoride probably extended vase life by controlling wound healing and delaying occlusions at the cut stem ends. Thereby, they facilitate the absorption of solution and reduce the rate of decline in relative fresh weight in the Gerbera cut flowers.

Gerbera ranks among the 10 superior cut flowers worldwide and is valuable from commercial perspective, but its short vase-life due to stem bent neck (stem break) and wilting are the most critical postharvest challenges of this cut flower. Nitric oxide (NO) is a signaling molecule in plants that involves functions in many physiological processes. In this research, the effects of NO on vase-life, physiological and antioxidant responses and stem neck of three gerbera cultivars (red, pink and yellow) were investigated. The structural and histological characteristics of gerbera stem were evaluated, too. The research was a completely as randomized design and a factorial combination flower color (red, pink and yellow) and three concentrations of SNP (0.25, 0.5 and 1 µM) with three replications. Distilled water was used as control. The results indicated that all concentrations of SNP possess antioxidant properties and increased the defense ability of plants. Based on the results, obtained irrespective of flower color, the highest vase-life and the lowest malondialdehyde and hydrogen peroxide were found in 1 µM SNP. The results showed that SNP not only increased vase-life and the activity of antioxidants enzyme and phenylalanine ammonia lyase (PAL), but also significantly decreased the activity of polyphenol oxidase. Moreover, SNP increased the lignin biosynthese of there mechanical tissue which in turn reduced stem neck possibly through the induction of PAL enzyme activity.

In recent years application of nanoparticles due to their antimicrobial properties has become widespread in the postharvest of agricultural plants. There is a high demand to increase the quality of post-harvest of commercially important cut flowers such as gerbera. In this study, different concentrations of silver nanoparticles (0, 5, 10, 20 mg/l) and hydroxyquinoline citrate (0, 200, 400 mg/l) were compared. During the experiment vase life, relative fresh weight, the uptake solution, the cell membrane stability index, water content of petals were measured. Results showed that the effect of silver nanoparticles and hydroxyquinoline citrate on most characteristics were significant. The maximum vase life was observed when hydroxyquinoline citrate and silver nanoparticles were used at 200 mg/l and 10, 20 mg/l respectively. Interactive effect of silver nanoparticles and hydroxyquinoline citrate significantly increased vase life, water content gerbera, cell membrane stability index, flower petals and the uptake solution during the trials.

This experiment was carried out to investigate the effect of different substrate on growth and yield of Gerbera flower. The experiment was performed using 10 treatments as fallow: fine sand، peat +fine sand (%25+%75)، peat + fine sand (%50 +%50)، perlite + peat (%75 + %25)، perlite + peat (%50 + %50)، perlite + peat (%25 + %75)، perlite + peat + expanded clay (%25 + %70 + %5)، perlite + peat + expanded clay (%50 + %25 + %25)، perlite + peat + expanded clay (25%+ %50 + %25)، peat + expanded clay (%50 + %50)، as a completely randomized design with 3 replications. All treatments irrigated with same nutrient solution. Results showed that planting beds statistically significant differences in morphological characteristics، macro and micro nutrients in plant. Results showed that the media containing perlite + peat + expanded clay (%25 + %70 + %5) is the best of all. In this treatment، flower number، flower disk diameter، shoot diameter، shoot neck diameter، flower height and vase life were 207 (m2/year)، 12. 4 cm، 0. 8 cm، 0. 58 cm، 54. 5 cm and 11. 6 days، respectively. In this treatment، concentration of Nitrogen، Phosphorus and Potassium were 4. 17، 0. 8 and 4. 34 percent، respectively and micronutrients concentration as Iron، Manganese، Zinc، Copper، and Boron on the plant leaves were 155. 73، 194. 83، 148. 56، 44. 92 and 51. 5 mg kg-1 dry weight، respectively.

Reduction of post harvest losses in cut flowers and increasing their vase life, with consideration to high expenses of production is very necessary. One of the effective factors is presence of flowers near each other. This study was performed to investigate the interaction of some important cut flowers on their post harvest characteristics in vase solution (in combination or alone) in 2007- 2008 at post harvest physiology lab of horticulture department of Ferdowsi University of Mashhad. In the first experiment the effects of gerbera and tuberose and in the second one the effects of daffodil, carnation and gillyflower on their post-harvest characteristics were investigated. Results of the first experiment showed that the presence of tuberose and gerbera in a vase solution caused significant reduction of gerbera vase life, but the effect of this factor is not significant on other gerbera characteristics. In addition the effect of gerbera on tuberose was caused significant reduction on tuberose fresh weight. Results of the second experiment showed that presence of gillyflowers near daffodils was caused significant reduction of daffodils vase life but the other flowers have not any effect on their vase lives. In the first day, the diameter of carnations flower was also reduced significantly when they were near daffodils in one vase solution. Treatments had not significant effects on fresh weight train. Vase solution turbidity was higher for those vases for two flowers than one flower. But this difference was significant only about the vase solution of daffodil + carnation. The highest solution pH was observed in the solution of daffodil and carnation alone and they had significant difference with the others.

To evaluate the possibility of replacing natural compounds for chemical ones as antimicrobial agents in preservative solutions of cut flowers, a factorial CRD based experiment of three replications was conducted at the Department of Horticulture, Faculty of Agriculture, Tehran University. Three concentration levels of 50, 100 and 300 mgL-1 from Eugenia caryophyllata were prepared. Cut gerbera "Ecco" flowers were continuously treated with each concentration of the compound. Results indicated that longevity, fresh weight, vase solution uptake, number of bacteria in preservative solution and color change of stems were affected by essential oils and extracts. Mean longevity of treated flowers with distilled water was 3.5 days, while mean longevity of treated flowers with Eugenia caryophyllata essential oil at 300 mgL-1 was 8.4 days and mean longevity of treated flowers with Eugenia caryophyllata extract at 100 mgL-1 8.3 days. Also it was observed that all the treatments endured more longevity than control flowers. Maximum values of fresh weight were observed in Eugenia caryophyllata essential oil at 300 mgL-1 followed by Eugenia caryophyllata extract of 100 mgL-1 concentration.

Gerbera is one of the most demanded plants in commercial cut flowers plants. Optimizing the micro-propagation of new cultivars is therefore important. In this research “Red Explosion” cultivar was used and Capitola (as explants) were directed to a modified solid Murashigue and Skoog medium with four concentration of TDZ (0.25, 0.50, 0.75 and 1.00 mgL-1) for regeneration. Three concentration of kinetin (4, 6 and 8 mgL-1) were applied and plantlets were transferred to free hormone medium for rooting. Number of new leaves produced, and fresh mass accumulation of cultured plantlets were used to determine the growth rate at 20 and 40 days after culture. Results showed that maximum shoot regeneration was occurred in 0.75 and 1.0 mgL-1TDZ. In proliferation stage first 20 days maximum increase in fresh weight in 6 mgL-1 kinetin and in second 20 days after culture in medium contained 4mgL-1 kinetin were observed. The highest number of new leaves was produced on the medium containing 6 mgL-1 kinetin and 87% of plantlets rooted after one month.