Breeding and Biotechnology of Plant and Flower
Davood Hashemabadi; Behzad Kaviani; Kobra Shakeri Kiasaraei; Rasoul Onsinejad; Mohammad Reza Safari Motlagh
Abstract
Introduction: Tulip flower (Tulipa L.) from the family Liliaceae is a bulbous and monocotyledon plant that has the highest level under cultivation among this family group. Tulips can be propagated by seeds and bulbs. Its seeds produce bulbs up to two years after planting and it takes six years for the ...
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Introduction: Tulip flower (Tulipa L.) from the family Liliaceae is a bulbous and monocotyledon plant that has the highest level under cultivation among this family group. Tulips can be propagated by seeds and bulbs. Its seeds produce bulbs up to two years after planting and it takes six years for the bulbs to reach the flowering stage. In fields, the quality characteristics of flowers can be changed to some extent by changing some planting characteristics such as planting pattern and plant density. Some researchers have reported changes in the quantitative and qualitative characteristics of various crops and orchards, including ornamental plants, with changes in planting pattern and plant density. One of the effects of changes in planting pattern and plant density is changes in photosynthesis and plant growth regulators. The purpose of this study was to introduce the best planting pattern, determination of the best planting density, and study the effect of plant pattern and planting density on the quantitative and qualitative characteristics of tulip (Tulipa L.) cv. ʹSpryngʹ.Materials and Methods: To evaluate the effect of planting pattern and density on growth and flower characteristics of tulip cv. ʹSpryingʹ, a study was conducted as a factorial experiment based on completely randomized block design (RCBD) with 3 replications in 27 plots. The first factor was three planting patterns (square, triangle and rectangle) and three planting densities (25, 45 and 65 plant/m2) as the second factor. Morphological and physiological traits such as height, length and diameter of stem, leaf and flower, flowering time, cut flower number, flower longevity, number, diameter and weight of bulb and bulblet, and the content of chlorophyll and carotenoid were measured. Statistical analysis of data was performed with SAS 9 software and mean comparison of the data with LSD test at 5% probability level. Graphs were drawn in Excel.Results and Discussion: Results showed that the maximum number of cut flowers (59.90) was counted in plants cultivated in triangle cultivation design with planting density of 65 plants/m2. The lowest time to start of flowering (69.30 days) and the highest content of leaf chlorophyll (13.57 μg/ml) was obtained in plants cultivated in trianle cultivation design with planting density of 45 plants/m2. The most flower longevity (12.73 day) and the highest content of carotenoid (1.68 μg/ml) was obtained in plants cultivated in square cultivation design with planting density of 45 plants/m2. The height of the flowering stem is one of the important traits for the marketing of cut flowers. The results of the present study showed that the height of the tulip plant was affected by plant density and planting pattern. This result was consistent with the results reported by some researchers. At low plant densities, long plant spacing reduces plant competition for water and nutrient uptake, resulting in larger plant growth and leaf size. Also, long plant distances cause the roots to develop and grow, and the leaves to grow and thicken. Increasing the vegetative competition of adjacent plants at high densities causes photosynthetic organs to be placed in the shade (change in the quantity and composition of the received radiation spectrum in the shade leaves), which has a great effect on the balance of plant growth regulators, resulted in longitudinal and superficial growth of plant organs. It intensifies the longitudinal growth of the petiole and accelerates all the developmental processes of the plant. Plant morphology and angle of leaf deviation can also be effective in increasing leaf size. Uniform distribution of plants and greater absorption of light and nutrients increased leaf length and width. The results revealed that plants compete for light and nutrients, and in these competitive conditions, roots and stems are taller than optimal, and the distance between nodes increases. The effect of planting pattern on flowering process can be related to changes in plant photosynthesis and the availability of photosynthetic materials for the developing reproductive parts. Changes in the planting distance or pattern change inflorescence characteristics by affecting root growth and altering the production of plant growth regulators in roots. Inflorescence characteristics are changed through the transfer of these plant growth regulators to the aerial parts. Changing the distance or planting pattern can affect some characteristics of bulb and bulblet of bulbous plants. Competition for receiving maximum light and photosynthesis is a key factor in changing bulb and bulblet traits. This competition is influenced by planting arrangement and plant density. Some studies have shown that planting pattern and plant density affect the amount of plant pigments such as chlorophyll and carotenoids, the main reason being the difference in light intake.
Medicinal Plants
Behzad Kaviani; Davood Hashemabadi; Rana Mohammadipour; Rasoul Onsinejad; Ahmad Reza Berimavandi
Abstract
Introduction
Damask rose (Rosa damascena Mill.) is used as a multi-purpose species (edible, medicinal, aromatic and ornamental). The flower essential oil of this plant has many applications in various industries. There is a wide variety of morphological, phonological, flower shape, yield and yield of ...
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Introduction
Damask rose (Rosa damascena Mill.) is used as a multi-purpose species (edible, medicinal, aromatic and ornamental). The flower essential oil of this plant has many applications in various industries. There is a wide variety of morphological, phonological, flower shape, yield and yield of essential oils among genotypes and different populations of Damask rose in various ecological conditions in Iran. Evaluation of genetic diversity among Damask rose of Iran is important in order for breeding purposes. Some studies on phenotype, essential oil and genetic diversity were also carried out among different cultivars of rose flowers in other parts of the world. Significant diversity has been reported among the populations and genotypes of rose in different ecological conditions for many traits. Identifying superior species, cultivars and populations is important for commercial cultivation and more essential oil production. It is difficult to understand genetic diversity in roses because natural hybridization and spontaneous mutations with high abundance occurs in this plant. Morphological differences can be due to the geographical coordinates, natural hybridization and mutations. Therefore, it is important to identify the genetic diversity among the Iranian rose flowers to improve the genotypes of these flowers with appropriate garden features. The purpose of this study was to investigate and compare the genetic variety of Damask rose in Guilan, Ilam, Golestan, Tehran and Kashan in order to introduce superior genotype based on essence content and some other morphological and physiological traits.
Materials and Methods
Five genotypes of Damask rose including Kashan, Ilam, Golestan, Tehran and Guilan genotypes were evaluated as plant materials. Plant materials were collected from mentioned-above regions as root-sucker and transferred to the farm of Research Institute of Forests and Rangelands of the country. The design used was a completely randomized block design, which was performed in 3 replications and was considered for each 5-suckers’ repetition (total: 75 suckers). In each replication, three specimens of each genotype were planted in pits with diameter and depth of 50-60 cm. The distance between scions per rows was 2.5 meters and row spacing from each other was 2 meters. During the experimental period, the bushes were irrigated using drip (trickle) irrigation method. The sampling was performed to measure morphological and physiological parameters after the blooms were opened in early May. Evaluated parameters were plant height, leaf length, leaf width, leaf area, petal number, stamen number, carpel number, fresh weight of petals, petal anthocyanin levels, petals essential oil levels, chlorophyll content and leaf carotenoids. Data were analyzed by ANOVA and, if significant, Tukey analysis was used. SPSS software was used for statistical analysis.
Results and Discussion
The results showed that the highest amount of essential oil (0.042 and 0.038%) was extracted from the petals of Ilam and Kashan genotypes, respectively. The highest petal weight (2.70 and 2.30 g) was related to the petals of Ilam and Kashan genotypes, respectively. The highest petal length and width were obtained in these two genotypes. The largest number of petals (71.80 per each plant) was related to Guilan samples. The highest amount of chlorophyll a was related to Ilam genotype and the highest amount of chlorophyll b, carotenoids and anthocyanin was related to Kashan genotype. Stamen number, carpel number, leaf area, leaf length and plant height were also measured. In the present study, rose flower genotypes collected from different parts of Iran showed significant diversity in relation to morphological and physiological properties, especially essence. The results of the present study showed that there was a significant correlation between the amount of essence in the petals and the weight and dimensions of the petals, so that the Ilam and Kashan genotypes with more essence in their petals had higher weight and dimensions. Similar findings related to the correlation between flower yield and its components in roses flowers were presented in some studies. The number of flowers per branch, the fresh weight of each flower and the number of flowers per branch can be a suitable choice for improving flower yield in rose flower genotypes. Some studies have shown that the weight of the flower has a very strong, positive and significant correlation with the flower yield. The findings of the present study confirm the results obtained in these studies. Despite the geographical distance between some genotypes, the high similarity coefficient between them may indicate the common origin or continuous and purposeful genotypes. On the other hand, the low similarity coefficient between genotypes proposes relatively low geographical connection and different primary origin. In the present study, there was a low correlation between the amount of essence in the petals and the weight and dimensions of the petals in the Ilam and Kashan genotypes with the Golestan and Guilan genotypes. Finding the high correlation between the more important traits is of high value in breeding programs and the selection of superior genotypes. Some reports have been presented to compare rose flower genotypes based on morphological properties. Generative traits, including flower characteristics, are more suitable for genetic and evolutionary evaluations than vegetative traits. The results of some researchers in Iran and elsewhere in the world showed that flower yield per plant is associated with some other traits, including flower number, dimensions and weight of flowers, and the number of branches in the plant. The genetic analysis of rose flower genotypes showed that some genotypes collected from different areas are genetically relevant and some are separate. This subject shows effective role of ecological conditions in changing and variability of different species and varieties. The results indicated that the difference in the amount of essential oil compounds is mostly influenced by environmental and physiological factors. Some studies have shown significant diversity in essential oil efficiency and yield in different samples of rose flowers. The morphological difference between the different genotypes of this flower indicates the presence of germplasm and the proper capacity to improve the traits and the ability to select the best genotypes using morphological markers to enhance flower yield in the country. Overall; Ilam and Kashan genotypes are suggested as superior genotypes for breeding programs.
Pomology
Saeedeh Keivanfar; Davood Hashemabadi; Behzad Kaviani
Abstract
Introduction Olive (Olea europea L.) fruit ripening is a slow and long process and has a great impact on fruit quality, including the amount of oil. Also, interrupting the harvest and extraction of olive oil causes unfavorable conditions in this fruit. Therefore, it is important to determine the best ...
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Introduction Olive (Olea europea L.) fruit ripening is a slow and long process and has a great impact on fruit quality, including the amount of oil. Also, interrupting the harvest and extraction of olive oil causes unfavorable conditions in this fruit. Therefore, it is important to determine the best time to harvest the fruit. Olive oil has unsaturated fatty acids and has an antioxidant activity. The analysis of maturation stages is a prerequisite for fruit harvest time in each cultivar and quality of olive products. The time of harvest and maintenance after harvest is two important factors in the quality and quality of olive fruit oil. The exact determination of olive harvest time depends on the geographical area, cultivar and climate, agronomic and fruiting conditions. Study on different olive cultivars in different regions of Iran and the world revealed that fruit harvest time plays an effective role on the morphological, physiological and metabolic parameters of fruit. The approximate time of olive fruit harvest is in different geographical points, November and October. The purpose of this study was to investigate the right time of olive fruit harvesting 'Arbequina' and 'Yellow' cultivars for obtaining maximum quality of fruit and oil.Materials and Methods A factorial experiment containing two factors; cultivar in two levels ('Yellow' and 'Arbequina') and harvest time in six levels (24th and 31th October, and 7th, 14th, 21th and 28th November) based on a completely randomized block design with two factors in 12 treatments, 3 replicates and 36 experimental units was done to determine the appropriate harvest time and its effect on oil quality. Physiologic parameters; percentage of oil, amount of phenolic compounds, degree of peroxidation, amount of oleic acid, force of separation of fruit from tail and acidity were evaluated. This research was conducted at the olive research station in Rudbar city in southern Guilan province using the removed olives from the Manjil ETKA station. The 6 trees from two cultivars; 'Arbakkin' and 'Yellow' (from each 3 tree) which were similar in terms of height, age, crown diameter, mean conditions and irrigation were evaluated. Trees were planted at 6 × 8 m intervals. After selecting trees, from each tree, 2 to 3 kg of olive was randomly harvested. In fruits with tail, the force needed to separate the tail of the fruit was measured by the force assessment device. Standard method numbers 4178 and 4179 standard institutes and industrial research of Iran were used to measure acidity and olive oil peroxide, respectively. Polyphenols were measured with spectrophotometer. To determine the percentage of oil, saccule was used. For measurement of oleic acid, gas chromatography (GC) was used. Data were analyzed using SAS software and their average comparison was done by Duncan.Results and Discussion Mean comparison of the interaction effect between cultivar and harvest time showed that the highest acidity of the fruit was obtained in 'Arbequina' cultivar, respectively harvested at two times 31th and 24th October. The highest fruit peroxide value and the highest percentage of oleic acid were calculated in 'Yellow' cultivar in 24th October. The highest value of polyphenol was obtained in 'Yellow' cultivar on 7th November. The highest percentage of fruit oil was obtained in 'Arbequina' cultivar on 31th October. The lowest force to separate the tail from the fruit was applied in 'Arbequina' cultivar on 31th October. The results showed that the best time to harvest 'Yellow' cultivar is 7th November and for 'Arbequina' cultivar is 14th November. The study on several olive cultivars in China showed that the most suitable fruit harvest time was in late October until mid-November. There was an adverse significant correlation between changes in total sugar content in fruit and leaf and oil accumulation in the fruit. The quality of fruit depends mainly to the type of cultivar, genetic characteristics, maturity and environmental conditions. Study on some olive cultivars showed that the ratio between sugars is different in various stages of fruit maturity and between different cultivars of olive fruit. Some studies have shown that the most suitable time of olive fruit harvest for canned preparation is early September and for extraction of oil, late September. Fruits should be harvested when they have the highest oil accumulation. The study on 'Koroneiki' and 'Mission' cultivars in Gorgan region showed that the amount of oil in the dry matter and the percentage of free fatty acids increased with increasing degree of maturity, while peroxide value was reduced. One of the causes of peroxide value reduction during maturity is reduction in lipoxygenase enzyme activity. This enzyme increases the peroxide value by effect on linolenic acid and linoleic acid. Based on these results, the best time to harvest for the above cultivars is early in December.
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
K. Hosseinzadeh Moghaddam; B. Kaviani; D. Hashemabadi; Sh. Sedaghathoor; M.R. Safarimotlagh
Abstract
IntroductionKiwi (Actinidia deliciosa) is rich in minerals, vitamins and antioxidants. Kiwi fruit is sensitive to ethylene and has high perishability. There are some physical and chemical methods to delay aging and maintain postharvest quality of fruits. Light irradiation is a physical and pollution-free ...
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IntroductionKiwi (Actinidia deliciosa) is rich in minerals, vitamins and antioxidants. Kiwi fruit is sensitive to ethylene and has high perishability. There are some physical and chemical methods to delay aging and maintain postharvest quality of fruits. Light irradiation is a physical and pollution-free method that has been reported to be effective in controlling fruit decay and increasing its shelf life. Sodium nitroprusside (SNP) acts as an important signal in some physiological activities of the plant. SNP improved the quality and durability after fruit harvest in some fruits.Amino acids are effective in delaying the aging process and increasing the postharvest life of horticultural crops. Arginine plays an important and vital role in plant growth and development processes. The positive effect of arginine in increasing the shelf life of some fruits has been reported. The aim of this study was to increase the shelf life and quantitative and qualitative characteristics of ‘Hayward’ kiwi fruit after harvesting with the use of blue light, SNP and arginine. Material and MethodsHealthy and uniform fruits were selected and exposed to blue light (6, 12 and 24 h) at a wavelength range of 470 nm by LED lamps, SNP (0.5, 1 and 2 mM) and arginine (0.5, 1 and 2 mM). The experiment was performed in a completely random design with 10 treatments in 3 replications with 30 plots and 10 fruits per plot. After immersing the fruits at different levels of arginine, SNP and distilled water (control treatment), the surface of the fruits was dried and then sterilized. The fruits were monitored daily and their quantitative and qualitative properties were recorded during the experiment. Parameters of shelf life, tissue firmness, flavor index, loss of fresh weight, proline, ionic leakage, malondialdehyde (MDA), and dry matter, as well the activity of ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) enzymes were measured. Analysis of data obtained from sampling during the experimental period and laboratory were performed using SPSS statistical software and comparisons of means was done based on LSD statistical test. Results and DiscussionThe results showed that SNP at a concentration of 2 mM caused the highest shelf life (117.20 days) and the highest proline content (80.14 mg/kg) in kiwi fruits. The reason for this increased shelf life may be that SNP delays ethylene production process by activating the genetic and biochemical mechanisms, thus increase the postharvest life of ethylene-sensitive products. The highest firmness (4.56 kg/cm2) and the lowest fresh weight loss (1.26%) was obtained in fruits treated with 12 h of blue light. Some of the most important causes of this finding are that blue light delays the peak time of ethylene production, and as a fungal agent, reduces fruits decay after harvesting. The data showed that 12-h irradiation of blue light and 2 mM SNP caused a significant increase in the amount of antioxidant enzymes (SOD, POD and APX) of kiwifruit. Other traits such as flavor index, dry matter content, ion leakage and malondialdehyde were also measured. Blue light treatment can effectively reduce the decay of many fruits during postharvest storage. The study on kiwifruit showed that the qualitative treatments of different lights on various cultivars at different times had a significant effect on some physiological, morphological and gene expression traits. LED irradiation was found to be a suitable method for improving the quality of nutrients and the quality of flavor after harvest of some fruits. SNP was a good treatment to maintain fruit quality and improve disease resistance in kiwi cultivar ‘Bruno’ during storage. Fruits treatment with arginine is a promising technology to reduce cold and brown damages by stimulating the activity of antioxidant enzymes. Plant resistance to environmental stresses due to the use of arginine is in order to the effect of this substance on polyamine accumulation through increasing arginine decarboxylase and ornithine decarboxylase enzymes and increasing proline accumulation by enhancing ornithine amino-transferase enzyme activity as well as increasing nitric oxide through increasing the activity of nitric oxide synthase enzyme. Quality of kiwi fruit decreases during storage due to rapid softening and contamination with some fungi. In this study, effective treatments were used to reduce these complications. Overall, the results of this study showed that 2 mM SNP caused the highest shelf life. The highest firmness and the lowest fresh weight loss were observed in fruits treated with 12 h blue light. 12-h irradiation of blue light and 2 mM SNP caused a significant increase in the antioxidant enzymes of kiwifruit.
Postharvest physiology
S.A. Razi; D. Hashemabadi; B. 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.
