Postharvest physiology
Davood Hashemabadi; Amirhossein Soleimani; Behzad Kaviani; Nayyereh Naziri Moghaddam
Abstract
IntroductionCut carnation flowers have high economic importance in the floriculture industry. The postharvest life of cut ornamentals, including carnation, is important in determining their quality and consumer preference. High production of ethylene is one of the most important factors that reduce the ...
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IntroductionCut carnation flowers have high economic importance in the floriculture industry. The postharvest life of cut ornamentals, including carnation, is important in determining their quality and consumer preference. High production of ethylene is one of the most important factors that reduce the postharvest life of this flower. High ethylene production causes the aging of some cut flowers. In order to increase the vase life of cut flowers, many researches have been done and various preservative solutions have been introduced, and in some of these solutions, disinfectants have also been used. One of the effective compounds in stopping or reducing ethylene production are alcohols. Ethanol stops ethylene synthesis in cut carnation. Cut carnation is climacteric flower and sensitive to high levels of ethylene. Therefore, the aim of this research was to investigate and compare the effect of different amounts of propanol, butanol and pentanol on the vase life and quality improvement of cut carnation flowers cultivar 'Nelson'.Materials and MethodsIn the present study, propanol, butanol and pentanol were used at the concentrations of 2, 4 and 6% for 24-hour pulse, in order to reduce ethylene production and increase the vase life of cut carnation cultivar 'Nelson' flowers. In February 2020, cut carnation flowers that were harvested at the commercial stage were prepared from a greenhouse in Mahalat city and were immediately transferred to the Postharvest Laboratory, Faculty of Agriculture, Islamic Azad University, Rasht Branch for treatment and evaluation of traits. This experiment was conducted as a completely randomized design in 30 plots. For each treatment, 3 replications and 5 samples for each replication and a total of 150 flower branches were considered. Some traits such as vase life, water absorption, dry matter, petal protein, leaf chlorophyll, ethylene production, fresh weight loss, flower opening index, Brix degree, lipid peroxidation and activity of antioxidant enzymes, peroxidase and superoxide dismutase were measured. To evaluate the vase life of cut flowers, the main criterion is the turning of the petals inward and the apparent wilting of the flowers. Data analysis was done using SAS statistical software and mean comparison based on Duncan's multiple range test.Results and DiscussionThe results of variance analysis of the data showed that the effect of different amounts of propanol, butanol and pentanol application was significant at 5% and 1% probability level on vase life and most of the traits measured in cut carnation flowers. This research revealed that propanol had a more effective role in reducing ethylene production and increasing the vase life than butanol and pentanol. The results showed that the longest vase life (14.11 days) was observed in cut flowers treated with 2% propanol. This treatment also caused the highest amount of water absorption, percentage of dry matter, petal protein and leaf chlorophyll, as well as the lowest amount of ethylene production. The lowest vase life (8.91 days) was observed in control cut flowers. The mean comparison of the different alcohol treatments showed that all treatments of propanol and butanol alcohols in different concentrations increased the absorption of solution by cut flowers compared to the control. Maintaining the water balance in cut flowers is one of the important factors in the vase life of cut flowers. The content of water uptake by cut flowers depends on the hydraulic conductivity of the water channel in the stem and the water potential difference between cut flower tissues and the preservative solution. The least plasma membrane damage was caused in cut flowers treated with 2% propanol. This treatment also caused the highest SOD activity. The short vase life of cut flowers is a global challenge, and efforts are being made to increase their vase life by using appropriate compounds in the vase solution. One of these compounds are alcohols, which have been used by some researchers in order to increase the vase life of various cut flowers. Alcohols are usually toxic for cells in high concentrations. Propanol and butanol in low concentrations inhibited the synthesis of ethylene and therefore increased the vase life of cut carnation flowers. These anti-ethylene compounds prevent the senescence of the petals, which is usually associated with the browning of the petals. Alcohols in optimal concentrations act as a signal and increase the vase life of cut flowers and improve their postharvest quality by reducing lipid peroxidation and inducing the activity of antioxidant enzymes. Similar findings were reported in cut alstroemeria, some carnation cultivars and chrysanthemum flowers.ConclusionThe present study showed the positive effect of disinfectant and antimicrobial compounds on increasing the vase life, some physiologic characters and antioxidants activity. This research revealed that propanol had more effective role in reducing ethylene production and increasing the vase life than butanol and pentanol. The results showed that the longest vase life was observed in cut carnation cv. Nelson flowers treated with 2% propanol.
Postharvest physiology
Seyyed Abbas Razi; Davood Hashemabadi; Behzad Kaviani
Abstract
Introduction
Carnation (Dianthus caryophyllus L.) is one of the most important cut flowers of the world. This flower is sensitive to postharvest ethylene and water stress and has short vase life. The use of retardants or inhibitors compounds of ethylene is an effective way to increase the postharvest ...
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Introduction
Carnation (Dianthus caryophyllus L.) is one of the most important cut flowers of the world. This flower is sensitive to postharvest ethylene and water stress and has short vase life. The use of retardants or inhibitors compounds of ethylene is an effective way to increase the postharvest life of carnation. Polyamines including putrescine (diamine), spermidine (triamine) and spermine (tetraamine) as new groups of plant growth regulators that are involved in various processes including increasing cell division, increasing enzyme biosynthesis, regulation of different developmental stages, differentiation, flowering, embryogenesis, rooting and maturity. These compounds exert their anti-aging properties by competing with ethylene production. Polyamines are low molecular weight organic compounds with aliphatic nitrogen groups that have different hydrocarbon rings and two or more amino groups (positive charge agents). These organic compounds bind to cell membranes, nucleic acids, and other macromolecules and are involved in chromatin formation, ion channel control, free radical neutralization, and gene expression. Cell membrane strength and stability play an important role in increasing the post-harvest life of horticultural crops. Putrescine is the major polyamine in plants, which is a precursor to the synthesis of spermidine and spermine, and its positive effect on increasing the vase life of some cut flowers has been reported. Vase life of cut flowers of chrysanthemum, rose and gladiolus was increased by application of putrescine. The purpose of the present research was to increase the vase life of cut carnation flower using different putrescine concentrations and application methods.
Materials and Methods
A factorial experiment based on completely randomized design with 10 treatments in 3 replicates, 30 plots and 150 cut flowers was employed to investigate the effect of different concentrations of putrescine (0.01, 0.02 and 0.05 mM) and its application methods (continuous, pulse and spray) on vase life of cut carnation (Dianthus caryophyllus L.) flowers. Some other traits such as water uptake, dry mater percentage, decrease of fresh weight, the content of leaf chlorophyll and sepal carotenoid, POD and SOD enzymes activity, MDA, decrease of °Brix (sucrose percentage in flower stalk, soluble sugar in stem end and sepal), ionic leakage, ethylene were also measured. The statistical analysis of data was performed using SAS. The least significant difference (LSD) test at P < 0.05 was used for comparisons of different means of various treatments.
Results and Discussion
Results showed that the maximum vase life was recorded in cut flowers treated with 0.02 mM putrescine as spray application. The lowest ethylene production, the highest water uptake and superoxide dismutase enzyme activity was observed in 0.02 mM putrescine treatment. Some physiological parameters and enzymatic activity were also evaluated. The control treatment generally yielded the minimum values for most of the observed traits. Factors such as water stress, reduced carbohydrate levels, increased ethylene production, and the presence of microorganisms play pivotal roles in reducing the vase life of cut flowers. Polyamines are key in counteracting these stressors and delaying aging. They fulfill this role by fortifying the plasma membrane, suppressing the activity of hydrolytic enzymes, and inhibiting ethylene synthesis. Additionally, polyamines bind to cell wall pectin, safeguarding them from detrimental cell wall enzymes, including pectinase. They further impede flower maturation by inhibiting the production of essential enzymes required for ethylene synthesis and by dampening ethylene activity. Increasing polyamines by inhibiting lipid peroxidation is probably one of the mechanisms responsible for the anti-aging effect of polyamines. Polyamines have antioxidant properties so they reduce the number of oxygen free radicals and the permeability of plasma membranes by decreasing the activity of lipoxygenase, thereby increasing the vase life and quality of flowers. The use of polyamines to increase the vase life of some cut flowers has been reported, which the results of the present study are consistent with the results of these studies. Treatment of 20 mg l–1 spermine and 10 mg l–1 putrescine had the greatest effect on increasing vase life and reducing senescence of cut Alstroemeria flowers. Spermidine delayed the aging of carnation flowers. In cut rose cv. ‘Doles Vita’ flowers, the use of polyamines increased vase life. Treatment of 2 mM spermidine was the most suitable treatment to increase the vase life of cut carnation cv. ‘Red Corsa’ flowers. Cut rose flowers treated with humic acid and putrescine had the highest vase life compared to the control. Polyamines increased the vase life of cut gladiolus flowers by increasing the stability of plasma membranes. The addition of polyamines to the carnation flower preservative solution reduced their aging and prevented the production of ethylene. Polyamines appear to increase vase life in cut flowers by inhibiting ACC-synthase activity and reducing ethylene production. SOD, POD and catalase (CAT) enzymes, as antioxidant compounds, protect plants against reactive oxygen species and free radicals. Polyamines neutralize free radicals and are also involved in the synthesis of enzymes. Binding of polyamines to proteins protects them from the damaging effects of reactive oxygen species and free radicals. Treatment of 20 mg l–1 spermine increased the activity of SOD enzyme in cut Alstroemeria flowers. Concentrations of 10 and 20 mg l–1 putrescine and spermine significantly increased catalase activity. Spermidine treatment significantly increased the activity of free radical scavenging enzymes such as SOD and CAT. Putrescine in sunflower stimulated the catalase enzyme. At the first onset of senescence, antioxidant enzymes such as POD increase in petal cells to reduce the damaging effects of reactive oxygen species.
Sheno Amini; Mostafa Arab; Majid Rahemi; Abdolrahman Rahimi
Abstract
This research was carried out in order to evaluate the influence of different concentrations of ethanol and methanol (0, 4, 6 and 12%) and two pulse treatments (12 and 24 hour) on longevity of cut standard-carnation (Sensi cultivar) in a factorial based on randomized completely design with three replications, ...
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This research was carried out in order to evaluate the influence of different concentrations of ethanol and methanol (0, 4, 6 and 12%) and two pulse treatments (12 and 24 hour) on longevity of cut standard-carnation (Sensi cultivar) in a factorial based on randomized completely design with three replications, at Tehran University, Aboreyhan Pardis, horticulture department, during 2010. The results showed that the effect of alcohol treatments and interaction effect of alcohols and pulse on vase life were significant (at what level?????), whereas solution uptake and relative fresh weight were not affected by mentioned treatments. The highest (17.33 day) and lowest (11 day) amount of carnation vase life were obtained by ethanol 12% at pulse of 12 hours and control treatments, respectively. Ethanol 6% at pulse of 24 hours, ethanol 12% and methanol 6% at pulse of 12 hours were more effective in increasing the longevity of carnation than other pulse, while in other treatments, no significant differences were observed between the pulse times. Moreover, the highest of ethylene production obtained by control, while ethanol 4% and 6% at pulse of 24 hours, ethanol and methanol 12% at pulse of 12 hours and methanol 6% at both time of pulse markedly decreased the production of ethylene and lead to significantly increase in vase life. The relative extension of flowers and relative fresh weight had a positive correlation with vase life, while solution uptake had non correlation or negative correlation with other treats.
Azam Seddighi; M. Gholami; Hassan Sarikhani; Ahmad Ershadi
Abstract
The use of compounds inhibiting ethylene production is very important in post-harvest technology of fruits. Sweet cherry is a non-climacteric fruit with capability of ethylene production during storage period. Factors that decrease ethylene production would increase fruits storage life. In this research ...
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The use of compounds inhibiting ethylene production is very important in post-harvest technology of fruits. Sweet cherry is a non-climacteric fruit with capability of ethylene production during storage period. Factors that decrease ethylene production would increase fruits storage life. In this research sweet cherry fruits of Mashhad cv. were sprayed with different concentrations of Salicylic Acid (0.5, 1, 2, and 3 mmol/l) and Gibberelic Acid (0, 10, 20 and 30 mg/l). Fruits were sprayed about three weeks before harvest, when their color started to change from green to yellow. The experiment was performed in a completely randomized design with three replicates. The results showed that GA had less effect on decreasing ethylene production compared to SA, but did better on anthocyanin accumulation, fruit size, soluble solids content and fruit weight. GA treatment delayed fruit ripening and ethylene production but had little or no effect on the fruit color as an important ripening index. During storage period also the total amount of anthocyanin in fruits increased due to hormone treatments whereas the ethylene production decreased compared to control fruits.
