1-MCP, low O₂ and high CO₂ reduce disorders and extend vase life of “Rosalin” gerberas during storage

Abstract

The hormone ethylene performs an important function in the processes related to the senescence of cut flowers, and, in particular, anti-ethylene treatments are recommended to extend the vase life of orchids. Among the treatments currently used for such postharvest treatment, 1-methylcyclopropene (1-MCP) is an efficient inhibitor of the autocatalytic production of ethylene. Although postharvest 1-MCP treatment is used to counter ethylene activity and delay senescence in fresh produce, its potential application in cut flowers has not been adequately tested. The objective of this study was to investigate the effect of 1-MCP treatment with modified atmosphere packaging on the shelf life of cut “Rosalin” gerberas. To this end, gerberas harvested at commercial maturity were divided into two groups: 1-MCP treatment (625 ppb at 4±1°C for 4 hours) and no treatment. Both groups of flowers were stored under normal and modified atmosphere conditions at 4±1°C and 80±5% relative humidity. The flowers were covered with materials of different characteristics for the modified atmosphere. To determine the differences between the treatments, quality parameters were examined in the flowers at 7-day intervals during the storage. The 1-MCP treatment with both the normal and modified atmosphere significantly reduced the overall postharvest loss in quality. The best results for the quality characteristics determined were obtained from the 1-MCP and 30 µm polyvinylchloride combined treatment. These results indicate that 1-MCP and a modified atmosphere treatment are good methods for extending the vase life, maintaining the visual quality, and reducing the loss of quality of gerberas.

Keywords:

• Gerbera
• postharvest treatment
• quality
• storage
• vase life

Introduction

Ethylene is a plant hormone for which the endogenous production has been associated with various senescence processes. Ethylene plays an important role in various stages of plant growth and development, including senescence, and the exposure to ethylene accelerates the senescence of flowers in many species (Woltering & van Doorn, 1988). The exposure to ethylene can reduce flower longevity by causing undesirable physiological defects to the vegetative and flowering organs. The negative effects of ethylene can be significantly delayed by the treatment with inhibitors of ethylene action, such as silver thiosulfate (Veen, 1979), 2,5-norbornadiene (Sisler et al., 1983; Wang & Woodson, 1989), and 1-methylcyclopropene (1-MCP) (Serek et al., 2006). In particular, 1-MCP shows several advantages, as it is a nontoxic cyclic olefin that competes with ethylene at the receptor level (Sisler et al., 1996) and has been added to the list of options for extending the shelf life and quality of products. 1-MCP has been found to prevent the damage caused by exogenous ethylene in numerous cut flower species (Blankenship & Dole, 2003). Modified atmosphere packaging (MAP) is another technique that has been used to prevent or retard postharvest fruit ripening and the associated biochemical and physiological changes by favorably altering the O₂ and CO₂ levels around the products. In recent years, the use of combined techniques in the postharvest handling of fresh products is increasing, and numerous authors have obtained good results using a combined treatment (Meir et al., 1995; Redman et al., 2002; Akbudak et al., 2005; De Pascale et al., 2005; Bishop et al., 2007).

In this study, we aimed to investigate the effects of 1-MCP, normal atmosphere (NA), and MAP alone and combination on the postharvest quality and vase life of “Rosalin” gerbera in terms of the physiological and morphological changes.

Materials and methods

Plant material

The gerbera cultivar “Rosalin,” which is widely grown in Yalova, Turkey, was used in this study. At the end of the 8-week-growth period, the flowers were harvested and brought to the Cold Storage Research and Application Unit of the Department of Horticulture, Uludag University, Bursa, Turkey. The below-standard flowers were discarded. Injury-free flowers of the same size (having a stem length of 40 cm) and shape and were selected for the experiment.

Treatments

The initial analyses were performed after the gerberas were selected for the trial, and the flowers were divided into the following four groups:

1.	flowers stored under NA conditions without 1-MCP;
2.	flowers stored in MAP without 1-MCP – the flowers were enclosed in plastic film packages (25×50 cm), 30 µm-thick low-density polyethylene (PE), with an O2 permeability of 5371 ml m−2 day−1 atm−1 at 23°C and a water vapor permeability of 7.50 g m−2 day−1 atm−1 at 37.8±1.1°C and 90±2% RH, polypropylene (PP), with an O2 permeability of 1128 ml m−2 day−1 atm−1 at 23°C and a water vapor permeability of 3.10 g m−2 day−1 atm−1 at 37.8±1.1°C and 90±2% RH, polyvinylchloride (PVC), with an O2 permeability of 62.70 ml m−2 day−1 atm−1 at 23°C and a water vapor permeability of 4.80 g m−2 day−1 atm−1 at 37.8±1.1°C and 90±2% RH, and sealed by a Petra FS 500 plastic covering machine;
3.	flowers stored under NA conditions after being treated with 1-MCP–the 1-MCP treatment (625 ppb at 4±1°C for 4 hours) was chosen according the recommendations of previous studies on the storage of cut flowers (Philosoph-Hadas et al., 2005; Ascough et al., 2006; Cuquel et al., 2007; De Pietro et al., 2010); and
4.	flowers stored in MAP after being treated with 1-MCP (625 ppb at 4±1°C for 4 hours).

All of the flowers, including the control group, were placed in cardboard boxes (40×50×40 cm) and stored dry in a cold room at 4±1°C and 80±5% RH for 35 days. The flowers were covered with plastic film packages using a Petra (FS 500, Metro, Istanbul, Turkey) plastic-covering machine (all of the flowers in a replicate together) to form the MAP. The temperature and humidity conditions during storage were determined using a TES-1310 digital thermometer and hygrometer (TES Electrical, Taipei, Taiwan) and a Sato thermohygrograph (Sato Keiryoki Mfg. Co., Ltd., Tokyo, Japan).

Physical and chemical analyses

The losses in weight, which occurred in the flowers during storage, were detected using a precision balance (0.01 g precision; Radwag PS 3600/C/1, Radom, Poland), considering the weight value in the previous analytical period.

The petal leaf rupture force (PLRF) properties of the flowers were estimated by performing compressive stress strain experiments by means of a biological material test device. The device was equipped with a 50 N capacity load cell (Sundoo 50 SH Digital Push Pull Gauge, Wenzhou, China). The accuracy of N was 0.01.

The changes in the diameter were determined using a digital caliper, considering the initial diameter value for each analytical period (CD-20CPX, Mitutoyo, Japan).

The samples obtained from the stems of gerbera flowers were subjected to extraction with acetone (90%). The absorbance values were monitored using a spectrophotometer (Thermo Spectronic, Nicolet evolution 100, England) at 645 and 663 nm, and the chlorophyll was calculated (Holden, 1976). Distilled water was used as the blank.

A Dräger Multiwarn II gas analyzer (Drägerwerk AG, Lübeck, Germany) was used for determining the O₂, CO₂, and C₂H₄ concentrations generated under the plastic film material.

The flower and stem colors of the gerberas were determined by two readings on the two different symmetrical faces of a flower from each replicate using a Minolta CR-300 Chroma Meter (Konica-Minolta, Osaka, Japan).

Petals (1 g each) obtained from the flowers were immersed in 80% ethanol at 75°C for 30 min. After cooling, 100 μl of 50 g l⁻¹ mannitol was added to the solution as the internal standard. The tissue was then homogenized and centrifuged at 3000×g for 10 min. The pellet was suspended twice in 2.5 ml 80% ethanol, and the three supernatants were combined and concentrated under vacuum below 50°C. The residue was redissolved in 1 ml distilled water and passed through a Sep-Pak C18 cartridge (Millipore, Milford, MA, USA), followed by 2 ml of distilled water. Aliquots of the eluate were separated using an high-performance liquid chromatography (HPLC) system (Jasco HPLC, Tokyo, Japan) equipped with a refractive index detector and a Shodex SUGAR SP0810 column (Showa Denko, Tokyo). The column was kept at 80°C and eluted with water at a flow rate of 0.8 ml min⁻¹. The peak identity was confirmed using authentic carbohydrates, and the peak area was determined using an integrator. The amount of each carbohydrate in the sample was calculated as follows:

where W_C is the weight of each carbohydrate, W_M is the weight of the internal standard (mannitol), A_C/M is the area of both peaks of each carbohydrate relative to the peak area of mannitol, and S_C/M is the relative response factor. The measurements were repeated three times (Ichimura et al., 1998).

After storage to determine the vase life, the flowers were re-cut underwater to a stem length of 38 cm and placed in 2 l glass vases containing 500 ml deionized water. The room was kept at 20±1°C, 60±5% relative humidity, and a 12-h photoperiod (18 µmol m² s⁻¹ fluorescent light). The end of the vase life was defined as the time that the flowers showed symptoms of petal wilting or curling, stem bending (≥90°) or breaking (Gerasopoulos & Chebli, 1999). Five flowers per treatment for each replicate were used.

Statistical analysis

The study was established according to a randomized plot factorial experimental design. The analyses were performed in three replicates, with five plants (uniform by the flower quality) in each replicate. The results obtained from the study were analyzed using an ANOVA, and the means were compared using the least significant difference test (P<0.05).

Results and discussion

Weight loss

The amount of weight lost increased depending on the duration of storage, ranging from 2.86 to 7.40% for the samples that were treated with the MAP. Moreover, it was also determined that the MAP and 1-MCP applications decreased the amount of weight lost. At the end of the 35-day storage, the weight loss for the samples without 1-MCP under the NA conditions was 72.75%, whereas it was 64.31% for the samples to which 1-MCP was applied. The lowest weight loss were obtained with the combined applications of 1-MCP+PP (2.86%) and 1-MCP+PVC (3.66%) (Table I), a result that is consistent with previous studies regarding MAP and 1-MCP (Akbudak et al., 2005; Geng et al., 2008). Moreover, in a study on the effects of 1-MCP on the physical structure of cv. “Vega” roses, the flowers treated with 1-MCP (500 ppb) exhibited a reduction in weight loss (De Pietro et al., 2010).

Table I. Changes in weight loss, petal leaf rupture force, flower and stem diameter changes, total chlorophyll and MAP content occurred during NA and MAP of gerbera.

								MAP^g
Storage period (day)	Treatment 1	Treatment 2	Weight loss (%)	Petal leaf rupture force (N)	Flower diameter changes (mm)	Stem diameter changes (mm)	Total chlorophyll (mg 100^−1 g^−1)	CO2(%)	O2 (%)	C2H4 (ppm)
0	Control	NA	0.0	1.6	0.0	0.0	48.3	0.0	0.0	0.0
	1-MCP		0.0	1.7	0.0	0.0	85.9	0.0	0.0	0.0
LSD			–	–	–	–	–	–	–	–
7	Control	NA	22.3 a^a	0.8 c	13.3 a	1.5 a	98.3 a	–	–	–
		PE	0.4 b	1.5 bc	9.7 ab	0.5 bc	74.3 abc	0.8 bc	19.0 a	0.0
		PP	0.7 b	2.3 ab	5.4 bc	0.2 c	85.8 ab	2.1 a	19.1 a	0.0
		PVC	0.4 b	2.1 ab	7.7 abc	0.6 bc	76.9 abc	0.5 c	20.7 a	0.0
	1-MCP	NA	15.9 a	0.9 c	7.4 abc	1.1 ab	51.5 c	–	–	–
		PE	1.6 b	2.3 ab	5.6 bc	0.5 c	60.1 bc	0.8 bc	18.4 a	0.0
		PP	0.2 b	2.1 ab	5.0 bc	0.7 bc	56.1 c	1.1 b	20.2 a	0.0
		PVC	0.4 b	2.4 a	3.5 c	0.4 c	67.0 bc	0.7 bc	13.5 a	0.0
LSD			6.6	0.9	6.1	0.6	29.1	0.5	8.2	–
14	Control	NA	36.5 a	1.0 c	48.2 a	2.1 a	63.3 ab	–	–	–
		PE	2.1 b	2.4 ab	24.5 b	1.2 b	45.3 b	0.8 ab	18.4 b	0.0
		PP	1.4 b	2.2 ab	25.5 b	1.2 b	70.4 a	1.1 a	20.0 a	0.0
		PVC	1.1 b	1.8 bc	21.3 bc	1.7 ab	76.6 a	0.3 b	20.6 a	0.0
	1-MCP	NA	32.2 a	1.7 a	30.8 b	1.7 ab	60.2 ab	–	–	–
		PE	2.5 b	2.7 a	11.3 c	1.3 b	75.1 a	0.7 ab	18.6 b	0.0
		PP	1.1 b	2.7 a	20.1 bc	1.5 ab	75.3 a	0.4 a	20.6 a	0.0
		PVC	0.6 b	2.8 a	18.1 bc	1.5 ab	73.7 a	0.5 b	20.6 a	0.0
LSD			7.7	0.9	12.9	0.7	24.5	0.6	1.0	–
21	Control	NA	53.7 a	2.3 a	81.8 a	3.8 a	84.2 a	–	–	–
		PE	4.2 b	2.2 a	36.8 c	2.1 bc	82.1 a	1.2 ab	17.9 b	3.7 bc
		PP	1.8 b	2.8 a	31.9 cd	1.8 c	73.7 a	1.2 ab	19.8 ab	0.8 bc
		PVC	2.3 b	2.3 a	23.4 de	2.6 b	72.2 a	0.7 b	20.5 a	0.5 c
	1-MCP	NA	50.9 a	2.3 a	58.2 b	2.5 bc	69.7 a	–	–	–
		PE	3.2 b	2.0 a	17.6 e	1.8 c	68.7 a	1.4 ab	18.1 b	12.8 a
		PP	1.7 b	2.5 a	25.5 cde	1.9 bc	70.9 a	1.7 a	19.5 ab	4.8 b
		PVC	1.9 b	2.6 a	22.4 de	1.8 c	67.3 a	1.6 ab	19.5 ab	4.7 bc
LSD			14.0	0.8	12.9	0.8	18.9	1.0	2.0	4.3
28	Control	NA	63.8 a	1.0 e	102.2 a	6.3 a	88.4 a	–	–	–
		PE	6.2 b	1.4 cd	44.2 c	3.0 c	74.9 ab	1.7 ab	14.4 b	19.0 a
		PP	4.3 b	1.8 ab	40.4 cd	2.5 c	90.74 a	3.4 a	17.5 a	23.7 a
		PVC	6.0 b	1.5 bc	28.5 d	3.0 c	75.0 ab	1.1 b	20.0 a	14.7 a
	1-MCP	NA	61.8 a	1.1 de	72.5 b	4.4 b	69.1 ab	–	–	–
		PE	4.4 b	1.5 bc	26.8 d	2.6 c	61.1 b	1.2 b	18.2 a	22.2 a
		PP	2.5 b	1.8 ab	32.0 cd	2.5 c	73.3 ab	2.2 ab	19.1 a	22.3 a
		PVC	2.9 b	1.9 a	29.8 d	2.7 c	57.8 b	1.4 b	19.8 a	22.3 a
LSD			10.4	0.3	14.3	0.7	22.7	1.9	2.8	14.0
35	Control	NA	72.7 a	0.4 e	125.2 a	6.7 a	85.7 ab	–	–	–
		PE	7.4 c	1.1 cd	60.6 c	4.4 bcd	59.4 abc	1.1 a	17.7 a	2.7 ab
		PP	5.4 c	1.2 bc	51.4 cd	3.8 cde	44.3 c	2.2 a	19.0 a	5.3 a
		PVC	7.2 c	1.5 ab	42.8 de	4.5 bc	52.5 bc	1.3 a	19.8 a	0.0 b
	1-MCP	NA	64.3 b	0.8 d	96.0 b	4.9 b	94.5 a	–	–	–
		PE	5.4 c	1.6 a	33.1 e	3.7 de	59.3 abc	1.2 a	17.8 a	3.0 ab
		PP	2.9 c	1.7 a	37.5 e	3.4 e	51.2 bc	2.1 a	18.9 a	3.0 ab
		PVC	3.7 c	1.7 a	34.2 e	3.7 cde	54.7 abc	1.2 a	19.9 a	2.0 ab
LSD			8.4	0.3	11.2	0.8	40.6	1.6	2.3	5.3
1-MCP, 1-methylcyclopropene; NA, normal atmosphere; PE, polyethylene; PP, polypropylene; PVC, polyvinylchloride; LSD, least significant difference; MAP: Modified atmosphere packaging.
^aDifferent letters in the same column indicate significant differences P<0.05.

Petal leaf rupture force

The PLRF is a parameter related to the resistance of petals against defoliation, and it exhibited a decrease depending on the progression of the storage time. The previous studies showed that 1-MCP application increases the resistance against defoliation and prevents defoliation (Han & Miller, 2003; Uthaichay et al., 2007). Similarly, MAP increased the petal defoliation force. The present study showed that the petal defoliation force was higher with the combined application of 1-MCP and MAP, as compared to the NA treatment (Table I).

Flower and stem diameter changes

The diameters of the flower and stem decreased depending on the storage time (Table I), results that can be attributed to the increased water loss in the flowers and decrease in flower viability. Compared to the control group, these decrease were less marked in the samples with the 1-MCP and MAP treatments. 1-MCP was found to be effective in protecting flower viability. Similarly, the MAP application significantly prevented the decreases in diameter in both the control groups and the groups receiving the 1-MCP treatment. The decrease in the flower diameter was 95.96–125.22 mm in NA, whereas it was 33.09–37.53 mm in the combined 1-MCP and MAP treatments (Table I).

Chlorophyll content

The amount of total chlorophyll in the stem fluctuated during storage (Table I). In previous studies similar to the present one, it was reported that the amount of chlorophyll decreased with the progression of the storage time but that 1-MCP and MAP applications delayed this by preventing chlorophyll degradation (Yamashita et al., 1999; Han & Miller, 2003).

MAP content

When the gas composition was examined, it was determined that the CO₂ content increased, whereas, the O₂ content decreased with the storage duration; the CO₂ increase in the control was higher than in the 1-MCP group (Table I). The data from a similar study indicated that 1-MCP application decreased respiration, possibly offering an explanation for this observation (Singh et al., 2011). No ethylene was detected in the MAP packages in the first weeks of storage, but it was detected after 21 days and gradually increased thereafter (Table I). The increase in ethylene depending on the storage time is similar to the findings of other studies (Kenza et al., 2000; Philosoph-Hadas et al., 2005).

Color

The color changes in the flower and stem were reduced for the 1-MCP samples in comparison to the other samples and were most apparent for the combination of 1-MCP and MAP (Table II). Thus, the combination of 1-MCP and MAP maintains flower viability and prevents chlorophyll degradation, thereby maintaining the green color of the stem. This effect of 1-MCP and MAP applications was also reported previously (Akbudak et al., 2005; Uthaichay et al., 2007).

Table II. Changes in stem and flower color occurred during NA and MAP of gerbera.

			Stem color			Flower color
Storage period (day)	Treatment 1	Treatment 2	L	a	b	L	a	b
0	Control	NA	47.9	13.0	18.1	74.9	26.7	14.2
	1-MCP		46.1	12.7	17.8	71.5	25.3	11.8
LSD			–	–	–	–	–	–
7	Control	NA	38.9 b^a	10.2 b	15.2 c	65.0 bc	24.2 a	13.7 a
		PE	44.0 ab	12.0 a	17.4 ab	73.0 a	23.1 a	12.2 b
		PP	44.3 ab	12.6 a	17.7 a	71.7 a	23.6 a	11.7 bc
		PVC	43.0 ab	12.1 a	17.0 ab	67.8 abc	22.1 a	10.9 cd
	1-MCP	NA	44.6 a	10.8 b	16.0 bc	63.6 c	21.0 a	11.5 a
		PE	44.2 ab	11.9 a	17.5 a	71.2 a	24.5 a	10.4 d
		PP	45.5 a	12.6 a	18.4 a	71.0 a	22.3 a	10.3 d
		PVC	44.7 a	12.4 a	18.0 a	70.0 ab	23.4 a	11.1 cd
LSD			5.6	1.0	1.5	6.0	6.6	1.0
14	Control	NA	28.4 d	6.9 ab	10.3 abc	25.5 c	10.1 c	4.6 d
		PE	37.3 c	5.6 b	8.6 c	42.2 b	12.4 bc	7.6 bc
		PP	36.9 c	5.2 b	7.8 c	44.9 b	9.1 c	6.5 c
		PVC	38.8 bc	7.0 ab	10.6 abc	46.0 b	11.8 c	6.8 c
	1-MCP	NA	37.3 c	9.6 a	14.6 a	26.4 c	9.8 c	4.2 d
		PE	44.7 ab	9.3 a	13.8 ab	61.2 a	16.7 ab	8.8 ab
		PP	49.9 a	6.1 b	9.4 bc	67.1 a	17.0 a	9.7 a
		PVC	49.8 a	5.3 b	8.3 c	65.3 a	18.6 a	9.5 a
LSD			6.2	3.1	4.6	10.5	4.6	1.9
21	Control	NA	35.5 b	8.1 c	13.5 b	43.6 d	16.2 a	9.6 b
		PE	46.9 a	9.3 abc	14.7 ab	65.1 ab	15.7 a	11.8 a
		PP	48.3 a	8.4 c	13.3 b	68.7 a	17.9 a	11.3 ab
		PVC	48.7 a	9.3 abc	14.5 ab	61.8 ab	19.8 a	11.8 a
	1-MCP	NA	38.3 b	8.7 bc	14.7 ab	51.5 c	20.1 a	11.0 ab
		PE	48.2 a	9.5 abc	15.4 ab	60.5 b	17.0 a	10.1 ab
		PP	47.2 a	11.0 a	16.9 a	67.1 ab	17.7 a	11.0 ab
		PVC	49.0 a	10.1 ab	16.0 a	68.9 a	17.2 a	10.7 ab
LSD			3.0	1.7	2.5	7.1	5.0	2.0
28	Control	NA	36.0 c	8.1 ab	13.2 a	50.4 c	12.4	14.4 a
		PE	47.8 ab	8.0 ab	13.1 a	62.3 ab	16.8 a	11.8 a
		PP	46.0 b	9.0 a	14.5 a	64.9 ab	17.0 a	13.0 a
		PVC	50.2 a	5.9 b	10.2 a	68.0 a	12.6 a	12.5 a
	1-MCP	NA	36.2 c	7.9 ab	14.0 a	45.0 c	14.1 a	10.6 a
		PE	48.7 a	8.8 ab	14.4 a	61.0 ab	18.4 a	10.7 a
		PP	48.1 ab	8.7 ab	14.1 a	58.6 b	15.2 a	11.7 a
		PVC	48.7 a	8.6 ab	14.2 a	64.5 ab	13.9 a	12.7 a
LSD			2.6	3.0	4.5	7.3	6.4	4.7
35	Control	NA	35.3 c	5.7 b	13.5 a	48.7 d	8.7 d	14.5 a
		PE	41.9 ab	9.0 a	17.0 ab	58.0 abc	15.1	12.5 ab
		PP	41.3 ab	8.7 a	16.4 b	61.6 a	15.8 bc	12.1 b
		PVC	41.3 ab	9.1 a	16.8 b	58.6 ab	18.7 ab	11.6 b
	1-MCP	NA	36.9 bc	6.1 b	14.9 a	47.7 d	10.8 cd	14.7 a
		PE	40.8 abc	8.4 a	16.6 b	56.3 bc	20.9 ab	11.2 b
		PP	39.2 abc	9.0 a	16.5 b	55.7 bc	24.3 a	11.1 b
		PVC	43.4 a	10.0 a	15.5 b	54.8 c	21.5 ab	10.7 b
LSD			5.7	1.7	2.2	3.8	6.4	2.2
1-MCP, 1-methylcyclopropene; NA, normal atmosphere; PE, polyethylene; PP, polypropylene; PVC, polyvinylchloride; LSD, least significant difference.
^aDifferent letters in the same column indicate significant differences P<0.05.

Flower fructose and glucose content

The fructose and glucose values decreased with an increased storage period (Table III). This result shows that carbohydrates present at the end of the harvest have an effect on the storage of cut flowers that the application of MAP has been previously reported to slow flower metabolism and, thus, carbohydrate consumption due to respiration (Meir et al., 1995; Zeltzer et al., 2001; Mattiuz et al., 2012). Moreover, it was also reported that the carbohydrate level in flowers to which 1-MCP was applied was decreased in comparison to those without 1-MCP (Singh et al., 2011). In addition, depending on the storage period, the decrease in carbohydrates was reported to cease toward the end of the storage period, and an increase in the level was then observed (Celikel & Karacali, 1995; Monteiro et al., 2002). This finding is also similar to the data obtained in our study and might explain why the glucose and fructose increases occurred earlier for the samples stored in the NA and later for the samples treated with the 1-MCP and MAP applications (Table III).

Table III. Changes in flower fructose, glucose and vase life occurred during NA and MAP of gerbera.

Storage period (day)	Treatment 1	Treatment 2	Flower fructose content (%)	Flower glucose content (%)	Vase life (day)
0	Control	NA	1.1	1.2	14.0
	1-MCP		1.0	1.1	17.0
LSD			–	–	–
7	Control	NA	0.9 a^a	1.1 a	12.0 e
		PE	0.8 d	0.9 e	13.0 de
		PP	0.9 c	1.0 d	14.0 cd
		PVC	0.7 f	0.9 e	13.0 de
	1-MCP	NA	0.9 b	1.0 b	15.0 bc
		PE	0.9 c	1.0 c	16.0 ab
		PP	0.7 g	0.9 f	17.0 a
		PVC	0.7 e	0.9 e	16.0 ab
LSD			0.0	0.0	1.7
14	Control	NA	0.8 h	0.7 c	9.0 e
		PE	0.9 g	0.6 f	10.0 de
		PP	1.1 a	0.8 b	10.0 de
		PVC	0.9 f	0.7 e	11.0 cd
	1-MCP	NA	1.1 c	0.8 a	12.0 c
		PE	1.1 b	0.8 b	14.0 b
		PP	1.0 d	0.7 d	16.0 a
		PVC	1.0 e	0.7 e	15.0 ab
LSD			0.0	0.0	1.7
21	Control	NA	0.6 c	0.8 a	7.0 e
		PE	0.6 f	0.4 g	8.0 de
		PP	0.6 e	0.4 f	9.0 cd
		PVC	0.6 d	0.5 e	10.0 c
	1-MCP	NA	0.5 g	0.6 c	10.0 c
		PE	0.6 f	0.4 f	12.0 b
		PP	0.7 b	0.5 d	14.0 a
		PVC	0.9 a	0.7 b	13.0 ab
LSD			0.0	0.0	1.7
28	Control	NA	0.8 b	1.0 a	5.0 d
		PE	0.5 d	0.4 e	6.0 cd
		PP	0.5 f	0.3 f	7.0 c
		PVC	0.5 e	0.3 f	7.0 c
	1-MCP	NA	0.8 c	0.9 b	9.0 b
		PE	0.5 e	0.2 g	10.0 ab
		PP	0.9 a	0.6 c	11.0 a
		PVC	0.8 c	0.5 d	10.0 ab
LSD			0.0	0.0	1.7
35	Control	NA	1.1 d	1.6 a	4.0 d
		PE	0.8 g	0.7 h	5.0 cd
		PP	1.5 a	1.2 c	6.0 bc
		PVC	1.2 b	1.0 d	6.0 bc
	1-MCP	NA	1.0 f	1.4 b	7.0 b
		PE	1.1 c	1.0 e	9.0 a
		PP	1.0 f	0.9 f	10.0 a
		PVC	1.0 e	0.9 g	9.0 a
LSD			0.0	0.0	1.7
1-MCP, 1-methylcyclopropene; NA, normal atmosphere; PE, polyethylene; PP, polypropylene; PVC, polyvinylchloride; LSD, least significant difference.
^aDifferent letters in the same column indicate significant differences P<0.05.

Vase life

The vase life exhibited a decrease proportional to the periods of storage; this decrease was more significant in the samples stored at the NA (Table III). The vase life, which was 14–17 days at the beginning of the study, decreased to 4–7 days at the end of the study for the samples stored at the NA. However, the vase life for the samples treated with the combination of 1-MCP and MAP was 9–10 days. In other studies concerning vase life, it was also determined that 1-MCP and MAP applications increased the vase life of cut flowers (Celikel & Karacali, 1995; Akbudak et al., 2005; De Pascale et al., 2005; Dole et al., 2005; Kim et al., 2011).

Consequently, our results suggest that the most important parameters to prolonging the gerbera storage period are the variety, storage temperature, application of 1-MCP, and different plastic cover materials. In this study, three film materials were used to assess the effects of 1-MCP and MAP treatments on the storage period and quality of gerbera cv. “Rosalin.” We found that the spoilage and aging were accelerated in the NA treatment. Moreover, changes in the quality parameters of the flowers could be kept within determined ranges by combining 1-MCP and different atmosphere treatments. The disorders were reduced with 1-MCP, low O₂ and high CO₂ during storage, and the treatments prevented the loss in quality. In conclusion, the flowers of gerbera cv. “Rosalin” could successfully be stored for 28–35 days using 1-MCP+30 µm PE to retain the best quality or with only slight changes in quality.

Acknowledgements

The authors thank the Scientific Research Projects Unit of Uludag University of Turkey for their financial support (UAP (Z)-2010-51).