Postharvest improvement of water relations and water uptake of cut flowers and control of microbial contamination of preservative solutions is one of the most important strategies in maintaining postharvest quality and prolonging of cut flowers vase life; especially for leafy flowering stems such as alstroemeria. This experiment was conducted to evaluate the effects of different peppermint’s essential oil concentrations (0, 300, 600 and 900 ppm) along with sucrose levels (0, 3 and 6%) in a factorial experiment based on the completely randomized design with three replications. Water relations, cell membrane integrity, leaf yellowing disorder and bacterial contaminations of preservative solution of alstroemeria cut flower were evaluated under different treatments. Based on the results, application of essential oil (600 ppm) and sucrose (6%) significantly increased water uptake, cell membrane integrity and photosynthetic pigments, and decreased leaf yellowing disorder and bacterial pollutions, leading, consequently, to higher vase life (14 days) relative to the control cut flowers. It appears that application of peppermint’s essential oil (due to anti bacterial compounds such as menthone and menthol) and sucrose (due to food supply and cell membrane maintenance) could be recommended for addition to the preservative solutions of alstroemeria cut flowers.

The effect of plant growth regulator short time treatments (GA3 and TDZ) on the increase of vase life and qualitative traits of Alstroemeria cultivars ‘Odessa’ and ‘Sacramento’ were investigated. Cut flowers were treated with 24h pulse treatments which included different concentrations of GA3 and TDZ. Cut flowers were later held in preservative solution (Sucrose 2% +Nanosid 2ppm) and then their vase life and qualitative traits evaluated on different days. The results indicated that GA3 300 µM treatment in ‘Odessa’ increased flower longevity while GA3 150 and 300 µM treatments increased leaf longevity. Moreover, GA3 300 µM treatment in ‘Sacramento’ deeply prevent affected the prevention of leaf senescence whereas the preservative solution more conspicuously affected the increase of flower longevity. In addition, 2ppm antibacterial Nanosid diminished the growth of microorganisms in preservative solution, in comparison with control (distilled water) and 2% Sucrose overcome the lack of carbohydrates in respiration process in cut flowers. Relative fresh weight and total soluble solids in stem increased in all treatments except in control. Also, GA3 (50, 150 µM) in ‘Odessa’ and GA3 300 µM in ‘Sacramento’ exhibited the maximum rate of total chlorophyll on the 12th day. Consequently, short duration treatment with 300 µM of GA3 is recommended in increasing the vase life and quality of cut flowers in ‘Odessa’ and ‘Sacramento’. Odessa’ is considered as a superior cultivar over ‘Sacramento’ and Nanosid in preservative solution being acknowledged as an appropriate antibacterial agent.

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.

In this research, synthesized silver nanoparticles by using saffron petals extracts were applied on inhibition of bacteria growth in preservative solution for extending vase life of rose cut flowers "White Naomi", in three separate experiments. In the first experiment effects of different ratios of silver nanoparticles and saffron petals extract (1:20, 1:5, and 1:2) were investigated on growth inhibition of five important preservative solution's infecting bacteria including Bacillus subtilus, Bacillus cereu, Acinetobacter, Pseudomonads fluorescens and Pseudomonas aeruginosa in completely randomized design with factorial arrangement. Results showed that applied concentrations had significant effect on growth of gram positive bacteria. Saffron petals extract didnt have any antibacterial effects in comparison with synthesized silver nanoparticles. 1:5 and 1:20 ratios showed the highest inhibition of bacterial growth in gram positive ones. In the second and third experiments effects of different concentrations of silver nanoparticles products were evaluated on vase life, relative fresh weight and relative solution uptake of rose cut flowers by two permanent and pulsing methods. Results showed that, low ratios of silver nanoparticles particularly 1:20 significantly increased vase life approximately two times in comparison to control due to increasing relative fresh weight.

Two experiments were designed to evaluate the addition of essential oils to preservative solution and subsequent effects on postharvest quality and vase life of Gladiolus ‘Sorati’ cut flowers. In first experiment, the solutions of savory (Satureja hortensis.), ajowan (Trachyspermum ammi) and thyme (Thymus vulgaris) were applied at the concentrations of 2, 4, and 6 (mg L−1), distilled water 2% sucrose were considered as control treatment. In second experiment, the cut flowers pulsed with CaCl2 and AgNO3 for 1 h and then transferred to preservative solution contain 2 mg L-1 of savory, ajowan, thyme and distilled water (control). All cut flowers were kept at 25±2oC for 20 days and qualitative properties were evaluated during postharvest periods. Savory 2 mg L−1 exhibited as the most effective treatment for minimizing dehydration of the gladiolus cut flowers by enhancing the water absorption and flower weight rate than other treatments. The interaction of pulsing with CaCl2 and essential oils could maintain the quality of cut flowers.

Rose (Rosa hybrida L.) is one of the mostly cultivated cut flowers in Iran and around the world. The study was carried out to increase the vase life and quality of cut rose ‘Grand Prix` and ‘Avallanche` by using various floral preservative solutions. Floral preservative solutions were AgNO3, 8-HQS, nano silver and distilled water. Treatments were compared with tap water as control. The experiment was arranged in a randomized complete block design. The effects of applied treatments on longevity and quality of cut rose flowers were evaluated by using the percentage of opening the flower, flower diameter, the vase life and relative fresh weight. Results showed that the flowers treated with 8-HQS (250 mg l-1) + nano silver (2mg l-1) had the highest flower diameter and the percentage of opening the flower among treatments. Maximum vase life (14.33 d) of cut rose obtained with (nano silver 2mg l-1), and minimum (6.54 d) with AgNO3. The vase life of control was 5.79 d.

In order to investigate vase life of cut foliages of cycad, the current research was carried out using various treatments of natural preservative solutions. Silver nitrate and sucrose were added to all treatments except the control treatment. Preservative solutions included coconut juice with two levels of 50% and 100%, lemon juice with concentrations of 0, 100, 250 and 400 ppm, silver nitrate with fixed concentration of 40 ppm and sucrose with fixed concentration of 3%. The combination of coconut juice and lemon juice resulted in 4 treatments. The experiment was carried out in 3 replications each containing 6 cut leaves. The aim of the experiment was increasing the vase life of cut foliages as the most important parameter. Some measured parameters during about four months of the study were vase life, chlorophyll content (chla, chlb, chl total), carotenoid, total soluble solid, water loss, external factors like changing, and fresh and dry weight of foliages. Among natural treatments, the best treatments for cycad cut foliages were 100 ppm lemon juice with 50% coconut juice which caused cycad’s cut leaves to preserve for 89 days (against 57 days in the control treatment).

This study was carried out to investigate the effect of different preservative solutions to improve the keeping quality of tuberose (Polianthes tuberosa cv. Single). These preservative solutions (treatments) were: T1= 2% sucrose 200 mg/l AgNO3, T2= 2% sucrose 200 mg/l AgNO3 25 mg/l citric acid, T3= 2% sucrose 300 mg/l HQS, T4 = 2% sucrose 300 mg/l HQS 25 mg/l citric acid, T5= 2% sucrose 200 mg/l AgNO3 300 mg/l HQS, T6= 2% sucrose 200 mg/l AgNO3 300 mg/l HQS 25 mg/l citric acid, T7= 0.01 % sodium hypochloride, T8= 0.05 % sodium hypochloride, T9= 0.10 % sodium hypochloride and T10= tap water (control). The results showed that all treatments had improved the keeping quality and vase life of the cut flowers comparing to control ones. Among all these treatments, 2% sucrose 200 mg/l AgNO3 300 mg/l HQS 25 mg/l citric acid showed best water uptake, water loss uptake ratio, percentage of maximum increase in fresh weight of the cut flower stem and vase life which was extended up to 10 days. According to the results of this research it is concluded that, 2% sucrose 200 mg/l AgNO3 300 mg/l HQS 25 mg/l citric acid are suitable for prolongation of tuberose vase life.

The tuberose (Polianthes tuberosa L.) is an ornamental plant related to the agaves, planted around the word. The main purpose of this study was to investigation of various concentrations of Thymus vulgaris L., Rosmarinus officinalis L., and benzyl adenine on longevity and durability of tuberose cut flowers. After extracting herbal extract and GC analysis, cut flowers were transferred to vessels containing preservative solutions. Then flowers were located in the controlled room. A factorial experiment in randomized complete block design with three replications was carried out in this research. Design include effects of treatments on quality of flowers, percent of total dissolved solids, water absorbance, stem bending, flower diameter, fresh weight and dry weight. GC analysis indicated that there were some compounds in the extracts increasing the shelf life of cut flowers. The most longevity (13.75 days) was related to treatment of interaction of thymus extract (10%) and 50mg/l benzyl adenine. In conclusion, treatments of benzyl adenine and thymus extract inhibited the growth of microorganisms in preservative solutions that resulted in increased post-harvest longevity.

The use of different dyes in changing the color of cut flowers is one of the new and emerging operations in order to increase diversity in the market of buying and selling flowers. In order to investigate the effect of different concentrations of food and industrial dyes on the vase life and physiological traits, an experiment was conducted in the form of factorial design based on a completely randomized basis with 3 replications. The first factor included dyes (control (without color), brilliant blue 4500 mg L-1, carmosin 4500 mg L-1, quinoline yellow 4500 mg L-1, acid orange 7 2500 mg L-1) and the second factor includes the preservative solution (distilled water and preservative solution including citric acid 300 mg L-1 + hydroxyquinoline sulfate 200 mg L-1 + sucrose 5%). The results showed that yellow quinoline dye + pulsing solution had the longest vase life (8 days), petal soluble solids (6.2%), the highest cell membrane stability and the least petal electrolyte leakage (23.5%) and the bacterial population of vase life solution (4.29 log10 CFU/ml). The relative fresh weight showed an upward trend until the second day, then a downward trend was recorded in all treatments. In the investigation of flower opening percentage trait, the orange acid 7 + distilled water treatment performed very poorly (6.87) and showed the lowest vase life (4 days) and the amount of soluble solids (2.52%) compared to other treatments. The control + distilled water treatment had the lowest relative fresh weight, the highest electrolyte leakage of petals (41.4%) and the highest bacterial accumulation in vase life solution (5.86 log10 CFU/ml). It seems that the use of food colors (Brilliant Blue, Carmosine, Quinoline Yellow) along with the use of preservative solution temporarily, in addition to creating variety, by improving the relative fresh weight index compared to undyed flowers and industrial colors (Orange acid 7), has increased the vase life of Polianthes tuberosa flowers.