عنوان مقاله [English]
Cut 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 Methods
In 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 Discussion
The 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.
The 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.