Plantmaterial and treatments: This experiment was carried out inApril 2016 on Alstroemeria cut flowers obtained from local commercialgreenhouse Mahallat located in the Markazi Province in Iran (longitude50°49′ E and latitude 33°87’N) and is1747 m above sea level. Plants were grown under standard greenhouse conditionsat 22?and 16?day and night temperatures.
Some of the plants were sprayed (approximately 500ml per plant) with different chemical compounds while the control flowers weresprayed with distilled water. About three weeks later, cut flowers followed byall plants were harvested in the early morning and transported with appropriatecover (in plastic packages) immediately to the laboratory of HorticultureDepartment. All flowers were uniformly recut with a height of 50 cm and put inthe prepared solutions after removing the leaves at their end of stem and weighting.R1 Vase life was defined as the time from the start of treatment until thesenescence of flowers. The vase life of cut flowers was evaluated in a 12-hourphotoperiod, the light intensity of 12 ?mol m-2 s-1,relative humidity of 60 to 70%, and the temperature of 20 ± 2?.Treatments used in this work are (Table 1).An aqueous solution of NS (5 and 10ppm), SA (200 and 300ppm), SP(10 and 20ppm), AN (50 and 100 ppm), CM (50 and100ppm), and distilled waterwere sprayed to run-off (approximately 500 mL per plant) about three weeksbefore flowers harvest. Next, both treated (sprayed) and untreated cut flowerswere harvested.
The cut flowers treated pre-harvest (B) were kept in vasesolution containing sucrose 3% with distilled water. Vase solutionconcentrations (pulsing 24h: A1) were distilled water with 20% sucrose. Vasesolution concentrations (continuous: A2) were NS (1and 3 ppm), SA (30 and 50ppm), SP (5 and 10 ppm), AN (5 and 10 ppm), CM (5 and 10 ppm), and distilledwater with 3% sucrose.
R2 Measurement of traits: Vaselife of the cut flowers was evaluated daily. The periodfrom the first day (0 day) when cut flowers were placed in vase solutions untilthey lost their ornamental value were measured. The end of Alstroemeria vaselife was determined with yellowing of 50% leaves or falling 50% florets (Ferrante et al., 2004).
In order to measure a, b, and total chlorophyll content ofthe plants, sampling was performed in the first and last days of the test. Theprocess of measuring chlorophyll was performed using Mazumdar and Majumdar(2003) method andfinally, the leaf chlorophyll content was suggested in mg g-1 of fresh weight.The difference between the amount of chlorophyll of first and last daysrepresents the degradation of chlorophyll, which is calculated using thefollowing formula:Chlorophyll a = 9.93 (A660) – 0.777 (A642.5)Chlorophyll b = 17.
6 (A642.5) – 2.81 (A660)Total Chlorophyll = 7.
12 (A660) – 16.8 (A642.5)Degradation ofChlorophyll a, b, total = Chlorophyll a, b, and total (first day) – Chlorophylla, b, and total (last day)SOD activity in petalsof cut Alstroemeria was measured at 1st, 4th, 8th, and 12th days based on thespectrophotometry by Giannopolitis and Ries(1977) method onpetal tissue.The reaction solution (1mL) contained 50 mM phosphate buffer (pH= 7), 12 mM riboflavin, 13 mMmethionine, 0.
1 mM EDTA, 7 mM nitro blue tetrazolium (NBT), and 10 ?L ofextracted enzyme solution. A solution with no enzyme was used as the control.Test tubes were irradiated under fluorescent lights at 100 mmol m–2s–1for 20 min. The absorbance of each solution was measured at 560 nm using aspectrophotometer. One unit of enzyme activity was defined as the amount ofenzyme that would inhibit 50% of NBT photo reduction.
For measuring Lipidperoxidation (MDA),a branch was removed at the end of vase life of thecontrol and its petals were measured as peroxidation reaction product ofmembrane fatty acids to determine peroxidation of lipids and lipid peroxidation(MDA) using Heath and Parker’s method (1968).To estimate bacterial populationin stems after treatments, 2-cm length (approximately 0.5 g) segments were cutfrom the stem ends. Explants were washed three times with sterile distilledwater to reduce surface microbial loads.
The explants were then ground anddiluted with 0.9% sterile herbal saline. Aliquots (0.1 mL) of extract werespread on nutrient agar plates, and bacterial colonies were enumerated afterincubation for 24 h at 37?. All bacteria counts were conducted ontriplicate sub-samples (Balestraetal., 2005).
Afterplate counting, obtained colonies were studied and separated by their apparentmorphological differences. As a result, 11 bacterial isolates were obtainedthat were purified and differentiated according to their typical morphologicaland biochemical characteristics. Bacterial morphological studies were motility,cell shape, and capsule presence. The biochemical tests carried out on isolatedbacterial colonies were Gram reaction using KOH, aerobic/anaerobic growth, acidproduction from glucose, gas production from D-glucose, fluorescent pigmentsproduction on KB, oxidase test, catalase test, gelatin hydrolysis, starchhydrolysis, urease, indole production, methyl red reaction, acetoin (VP),nitrate reduction, and H2S production from cysteine (Janse,2005).Statistical analysis:Datawere subjected to analysis of variance (ANOVA) in SAS statistical software.Sources of variation were different concentrations of treatments and methods.The mean values were compared by the Least Significant Difference (LSD) test atthe 0.
05 and 0.01 of probability level. R1??? R2How theconcentration of different compounds were selected. Either they werestandardized earlier or through review?