The effect of sucrose,silver thiosulphate and 8-hydroxyquinoline citrate on the quality of Lilium inflorescences cut at the bud stage and stored at low temperature

A continuous supply of sucrose together with 8-hydroxyquinoline citrate to cut Lilium Asiatic hybrid ‘Prima’ inflorescences resulted in buds opening satisfactorily and increased their longevity. The best results were obtained using 30 g l^?1 sucrose. Cut Lilium inflorescences could be stored at 1°C for 4 weeks without a great loss in potential vase-life and decorative value when the inflorescences were pre-treated with silver thiosulphate + 100 g l^?1 sucrose for 24 h before cold storage, kept in a cold room in a solution containing 50 mg l^?1 silver nitrate, and after cold storage kept in a solution containing 30 g l^?1 sucrose and 200 mg l^?1 8-hydroxyquinoline citrate. Such treatment greatly improved bud opening, increased the diameters of individual flowers and prolonged their life.     

Effect of green tea extract powder on the vase-life of fresh-cut rose (Rosa hybrida L.) ‘Carola’ stems

To develop an innocuous, easy-to-use, and inexpensive preservative for the cut flower industry, green tea extract (GTE) powder was applied in the fresh-cut rose stem preservation process to exploit its high anti-oxidative and anti-microbial properties. The effects of 2.0 g l^?1 GTE powder in the vase solution on the vase-life and flowering profile of cut rose (Rosa hybrida ‘Carola’) stems were investigated. The effectiveness of GTE powder was also compared with other preservatives such as 2% (w/v) sucrose, 200 mg l^?1 8-hydroxyquinoline citrate plus 2% (w/v) sucrose, or 0.2 mM silver thiosulphate in the vase solution, with distilled water as a control. The results showed that, compared to the control, the 2.0 g l^?1 GTE powder treatment extended the vase-life and reduced the loss in fresh weight in cut rose stems in the vase solution. GTE at 2.0 g l^?1 provided the highest anti-bacterial activity (4.2 log₁₀ CFU ml^?1 on day-6) and prevented the decline in anthocyanin concentrations compared to that seen in the control stems, suggesting that GTE powder could be used as a preservative to extend the vase-life of fresh-cut rose flowers.     

Evaluation and improvement of post-harvest performance of cut Viburnum tinus inflorescence

Post-harvest performance of cut viburnum inflorescences was examined in the present study. Harvesting viburnum at three developmental stages resulted in significant differences on flower opening rate (FOR) and flower abscission rate (FAR), but not on vase life. Harvesting at Stage III (>50% open flowers) resulted in highest flower opening percentage, whereas harvesting at Stage I (10–30% open flowers) in significantly lower flower abscission percentage. Pulsing with 20 or 40 mg/l AgNO₃ for 24 h extended vase life by 1.6 and 1.9 days, respectively, compared to the controls. Furthermore, flower abscission was significantly reduced after 20 or 40 mg/l AgNO₃ treatments by 51 and 62%, respectively, compared to the controls. In contrast, vase solutions containing 100 mg/l DICA or 100 and 200 mg/l methanol did not extend vase life of cut viburnum inflorescences, but significantly reduced flower abscission. Vase solutions containing 1 or 2% (w/v) sucrose negatively affected vase life, flower opening and flower abscission of viburnum inflorescence. Post-harvest treatments with 1-MCP at 10 μl/l in an ethylene-free environment resulted in extension of vase life and in significant reduction of FAR and respiration rates compared to the controls. Vase life of 1-MCP treated inflorescences was increased by 4.2 days compared to the controls. FAR of 1-MCP treated inflorescences remained significantly lower from the second to the eighth day of the vase life period.     

Water relations and microbial proliferation in vase solutions of Narcissus tazetta L. cv. ‘Shahla-e-Shiraz’ as affected by biocide compounds

Summary

Disruption of cut flower water relations due to the growth and proliferation of microorganisms in the vase solution is one of the most important factors causing reduced vase-life and deterioration in cut flowers. These experiments were conducted to study the effects of some biocides in controlling microbial proliferation in vase solutions and on water relations in cut Narcissus tazetta L. cv. ‘Shahla-e-Shiraz’, a native bulbous cut flower of Iran. The stems of ‘Shahla-e-Shiraz’ Narcissus cut flowers were exposed to 17 treatments: aluminium sulphate (at 100, 200 or 300 mg l^–1), citric acid (at 150, 300 or 450 mg l^–1), 8-hydroxyquinoline citrate (at 200, 300 or 400 mg l^–1), sodium hypochlorite (at 400, 600 or 800 mg l^–1), calcium hypochlorite (at 400, 600 or 800 mg l^–1), sterilised distilled water, or tap water (control). Generally, the least effective compounds in controlling microbial proliferation were low concentrations of aluminium sulphate or citric acid. 8-Hydroxyquinoline citrate treatments were most effective, and the vase solution did not contain any microbes until day-6. Vase solution contaminants were yeasts, Bacillus ssp., Staphylococcus ssp., Actinomycetes and Aspergillus ssp. Yeasts and bacilli were the most common microorganisms. Severe symptoms of phytotoxicity such as bud abortion and yellowing in aluminium sulphate-treated flowers, stem proximal-end browning and shrinking in 8-hydroxyquinoline citrate-treated flowers, and bleaching of soaked parts in sodium hypochlorite treatments, were seen. Most solution was taken up in 150 mg l^–1 citric acid, while the reduction in fresh weight was least in 200 mg l^–1 8-hydroxyquinoline citrate. The correlation between microbial counts and growth rate with solution uptake was slightly negative, but their correlation with fresh weight loss was slightly positive.     

Long-term storage of carnations cut at the green-bud stage

Carnation (Dianthus caryophyllus L.) cultivar ‘Scania 3C’ flowers were cut, either as tight buds or when coloured petals had begun to be visible as a “red cross”, and treated with various chemical solutions prior to storage for 14, 16, 20 or 24 weeks at 0–1°C.Pre-conditioning in a solution containing silver thiosulphate (STS) 550 mg/l and sucrose (S) 100 g/l improved the quality of flowers opened after 14 weeks of storage; flower diameters and vase-life were similar to those of fresh, non-stored flowers. Carnation buds were also successfully stored for up to 16 weeks when pre-conditioned with STS and sucrose, but the vase-life of opened flowers was shorter than that of freshly cut buds. The use of this preservative in conditioning, combined with dip treatment in a 0.1% solution of the potent fungicides Rovral or Sumilex before storage, improved the quality of flowers after 16–24 weeks of storage and allowed a vase-life of 7–8 days, respectively. Storage of carnation buds for 20 weeks at low pressure conditions (LPS) considerably improved the quality of flowers compared with 20 weeks of a standard air-storage technique. Carnation buds stored under LPS conditions all developed into fully opened flowers, irrespective of pre-conditioning, although acceptable quality and vase-life were only achieved by those which were pre-conditioned with STS+S prior to storage.     

Author index

Open carnation (Dianthus caryophyllus L.) flowers survived storage at ?3°C for 20 days if previously pulsed with 6% dimethylsulfoxide (DMSO) and 20% sucrose. However, vase life after removal was only 1 day. With 15 days storage, such flowers were acceptable for 7.5 days. With DMSO alone, the possible freezing time was shorter than with sucrose alone. A 5% solution of DMSO increased longevity compared to the water control when flowers were not stored.     

Regulation of postharvest flower senescence in Zinnia elegans Jacq.

Postharvest decorative life of Zinnia elegans flowers was prolonged by holding-solutions containing 8-hydroxyquinoline citrate (8-HQC) and sucrose. Flowers lasted longest in a solution of 200 mg l^?1 8-HQC and 1% sucrose. Flowers held in 2 or 3% sucrose and 200 mg l^?1 8-HQC developed necrotic lesions on ray florets and foliage. The decorative life of flowers held in 0.25 or 0.5% sucrose and 200 mg l^?1 8-HQC was extended beyond those in de-ionized water, but this extension was less than, or equal to, the postharvest life of those in 1% sucrose and 8-HQC (200 mg l^?1), depending on the cultivar. Postharvest life of flowers produced in May — June under natural photoperiod was significantly longer than that of flowers produced during February to April under a 14-h day provided by incandescent light.     

The effect of preservatives on water balance in cut clematis flowers

A positive water balance is crucial for longevity of cut shoots. When water loss by transpiration exceeds water uptake by cut flowers, wilting symptoms appear. Clematis is a very attractive plant which can be used as a cut flower provided that suitable cultivars are chosen. The vase life of four cultivars tested ranged between 6.7 days and 9.0 days and the standard preservative – 200 mg·dm^?3 8-hydroxyquinoline citrate (8HQC) plus 2% sucrose – prolonged it significantly in two cultivars, while 8HQC alone was efficient in only one. The preservatives delayed reduction in fresh weight. An enhancement of water uptake by the preservatives resulted in prolonged vase life of flowers in two cultivars. However, the effect of preservatives on transpiration was not related to longevity. In addition, longevity did not depend on the xylem vessel size: the cultivar with the longest vase life had the lowest average xylem vessel diameter while the cultivar with the largest vessels had an intermediate vase life. Preservatives did not always affect the number of blockages in xylem appearing during vase life. Generally, the effects of preservatives on the elements of water balance in cut shoots of clematis were not directly related to the postharvest longevity.     

Improving the postharvest performance of cut spray ‘Prince’ carnations by vase treatments with nano-silver and sucrose

The postharvest performance of cut spray-type carnations (Dianthus caryophyllus L.) is often limited by the opening, longevity, and coloration of individual florets, and is apparently related to water stress and sugar deficiency. In this study, we found that, compared with deionised water-treated controls, the vase life of cut spray ‘Prince’ carnations was extended by 2.1–4.6 days when held in vase solutions containing1–5 mg L^–1 nano-silver (NS). Moreover, combination treatments with 5 mg L^–1 NS and 2%, 3%, or 4% sucrose consistently further prolonged the vase life, prominently promoted floret opening, and increased the bright pink coloration of petals, thereby markedly enhancing quality performance. Overall, the 5 mg L^–1 NS plus 3% sucrose treatment provided the longest vase life extension (6.6 days) compared with the control, and significantly increased the anthocyanin content in floret petals. Besides, we also showed that the treatment with 5 mg L^–1 NS alone or 5 mg L^–1 NS plus 3% sucrose significantly enhanced their vase solution uptake and relative fresh weight. Further, scanning electron microscopy observations revealed that the NS vase treatments evidently alleviated vascular occlusion by inhibiting bacterial colonisation and biofilm formation on their stem-end cut surfaces and in the xylem vessels.     

Reversal of ethylene inhibition of tulip stem elongation by silver thiosulphate

Cut flowering stems of Tulipa cultivars were treated with a range of silver thiosulphate (STS) solutions (0.01–2.0 mM) for different times (10 min–24 h). The extension of the stem and longevity of the perianth were then observed at 18°C with the stems in water. At the highest dose (2.0 mM STS), a metallic silver sheen appeared on the surface of the STS solution and leaves were damaged. At non-toxic levels there appeared to be no effect on perianth longevity. However, the STS treatment completely reversed the inhibition of stem elongation caused by treatment with ethephon (48 mg l^?1 for 24 h) or with ethylene (C₂H₄, 1 v.p.m. for 41 h). The results suggest that in spite of the lack of effect of STS on corolla longevity, the STS is freely mobile in the vascular tissue and in trace amounts blocks the effects of C₂H₄. Silver nitrate was not as effective as STS.Measurements of STS uptake suggest that about 1 μmol of silver is sufficient to counter the inhibitory effects of ethylene on stem elongation.     

Chemical pre-treatment of snapdragon spikes to increase cut-flower longevity

The longevity and quality of freshly cut snapdragon (Antirrhinum majus L.), as well as those kept under simulated transport, were enhanced by 20 h pre-treatment with a solution containing silver thiosulphate and sucrose, compared to those pre-treated with silver nitrate on sucrose alone. Solutions of silver nitrate, sucrose and EDTA or 8-HQC as a complexing agent were less effective in prolonging snapdragon vase-life. The results of experiments with radioactive silver showed that spikes treated with silver thiosulphate solution accumulated the greatest amount of silver, especially in the shoots.     

保鲜液对蒟蒻薯切花瓶插寿命的影响

 蒟蒻薯（Tacca chantrieri Andre）是观赏价值较高的稀有黑色切花,但瓶插寿命较短,对其进行保鲜研究具有重要意义。用蔗糖、8–羟基奎宁（8-HQ）和柠檬酸按三因素二水平的正交设计配制瓶插保鲜液,通过观察切花形态变化,测定瓶插寿命和鲜样质量,研究瓶插液的保鲜效果。结果表明,与对照相比,各处理均能不同程度地延缓切花衰老,其中A处理,即2%蔗糖 + 100 mg · L^-1 8-HQ + 200 mg · L^-1柠檬酸 + 50 mg · L^-1 6-BA + 100 mg · L^-1 K₂HPO₄处理效果最好,花枝寿命和花须寿命分别比对照长17 d和14 d,是蒟蒻薯切花较好的瓶插保鲜配方。     

Prolongation of vase-life of Lupinus hartwegii Lindl. by chemical treatments

The effects of different concentrations of citric acid, aluminium sulphate, maleic hydrazide and sucrose were studied on cut stalks of Lupinus hartwégii. Citric acid and aluminium sulphate considerably enhanced the number of fresh flowers. Maleic hydrazide at 200 and 400 p.p.m. caused a significant reduction in the extent of abscission of flower buds and withered flowers. At 9% sucrose, withering was markedly enhanced. A maximum vase-life of 5.3 days was noted at 500 p.p.m. of citric acid as compared to 2.9 days in the controls. Probable explanations for the findings have been put forward and the results have been discussed in the light of available literature.     

乙烯对‘洛阳红’牡丹切花开放衰老进程及内源乙烯生物合成的影响

 以开花指数为1级的‘洛阳红’牡丹切花为试材，研究了外源乙烯和乙烯作用抑制剂1-甲基环丙烯（1-MCP）处理对其采后开花衰老进程中开花指数、花径增大率、瓶插寿命、内源乙烯生成量及乙烯生物合成关键酶ACC合成酶（ACS）和ACC氧化酶（ACO）活性的影响，从乙烯生物合成角度探讨了乙烯对其采后开花衰老的调节机理。结果表明，10 μL·L^-1乙烯处理6 h明显加快了‘洛阳红’花朵开放进程，缩短了切花的瓶插寿命，并促使其在盛开后出现严重落瓣；1.0 μL·L^-1 1-MCP处理6 h则延缓了花朵开放，延长了瓶插寿命，但却影响了部分切花的充分开放；内源乙烯的生成分别受乙烯和1-MCP处理的促进和抑制，与切花的开放衰老进程密切相关。不同处理后ACS、ACO酶活性分析表明，ACS活性变化与内源乙烯的生成相联系，是影响牡丹切花开放衰老进程的主要因子，这与目前得出的ACS是植物乙烯生物合成限速酶的研究结果相一致。     

不同预处理液对香石竹切花保鲜的影响

研究不同浓度组合的蔗糖、AgNO3、CaCl2、水杨酸钠预处理液对香石竹切花保鲜效果的影响.结果表明:50 g/L Suc+10 g/L CaCl2 +20 mg/L SA预处理液对香石竹切花的保鲜效果最好.可有效提高香石竹切花的吸水能力,提高SOD活性,降低MDA含量,延长了切花寿命.     

Vascular blockage in cut roses in a suspension of Pseudomonas fluorescens

Summary

To analyse quantitatively the relationships between cut rose (Rosa hybrida L. ‘Pascha’) vase-life, the onset of cavitation, plant water potential, and bacterial concentrations in the vase water, rose stems were placed in water containing different concentrations of Pseudomonas fluorescens 2892 tet^r rif ^r. There was a significant correlation (P = 0.0009) between cut rose vase-life and the concentration of bacteria in the vase water. As the number of bacteria in the vase water increased, the rate of senescence also increased. The water potential for roses in the bacterial suspension (at 8.50 log₁₀ CFU ml^–1) proceeded to drop constantly after 5.17 h in the vase solution, with the water potential falling to as low as -2.35 MPa by the end of the experiment (at 117 h). In contrast, the water potential of roses in deionised water dropped from -0.419 MPa at 5.17 h, to only –0.663 MPa after 117 h. When roses were stood in a bacterial suspension (at 8.5 log₁₀ CFU ml^–1) for 30 h, 63.8% of the total cumulative cavitation events were seen, while roses stood in deionised water exhibited only 26.8% of the total cavitation events. Uptake of acid fuchsin and the movement of tagged P. fluorescens 2892 in the xylem indicated that bacteria did not travel beyond the open-ended xylem vessels and were generally restricted to the first 50 mm from the cut end of the stem.     

Effects of 1-methylcyclopropene (1-MCP) on ripening of apple fruit without cold storage

Summary

The objectives of this study were to determine the efficacy of 1-methylcyclopropene (1-MCP) treatment on ripening of ‘Tsugaru’ fruit at different stages of maturity (early, mid-, and late harvest) and the responses of the early- to late-maturing apple cultivars,‘Tsugaru’,‘Hongro’ and ‘Fuji’, respectively, during storage at ambient temperature (20º ± 2ºC). Fruit at different stages of ripening were treated with 0.5, 1.0, or 2.0 µl l^–1 1-MCP for different durations (e.g., 1.0 µl l^–1 1-MCP for 8 h, 16 h, or 24 h) or with various delays before treatment (e.g., 1.0 µl l^–1 1-MCP on the day of harvest, or 1 d, or 2 d later). Application of 1-MCP to unripe fruit inhibited ethylene production, lowered the rate of respiration and maintained titratable acidity (TA) more effectively than when more mature fruit was treated. However, the effects of 1-MCP on flesh firmness were similar for apples at mid- or late harvests. 1-MCP treatment of early-harvested fruit of the early-maturing ‘Tsugaru’, which had the highest level of ethylene production and respiration rate, inhibited softening and loss of TA to a greater extent than for late harvested fruit. The same pattern of softening was found for ‘Hongro’ and ‘Fuji’. Firmness of ‘Tsugaru’ and ‘Fuji’ apples was maintained after 8 h treatment with 1.0 µl l^–1 1-MCP, while a 16 h treatment was required for ‘Hongro’. Treatment delays of ≤ 2 d before the application of 1-MCP had no negative impact on fruit firmness. Overall, these results indicate that 1-MCP can be used to maintain the quality of non-refrigerated apples.     

不同保鲜液对龙船花切花的保鲜效果

以龙船花（Ixora chinensis）切花为试材,通过测定瓶插寿命、鲜样质量、花瓣质膜透性和花瓣蛋白质含量,研究不同浓度配比的蔗糖、KH2PO4、8–羟基喹啉（8-HQ）和柠檬酸（CA）保鲜液对保鲜效果的影响。结果表明：2%蔗糖 + 150 mg · L-1 KH2PO4 + 120 mg · L-1 8-HQ + 30 mg · L-1 CA保鲜液处理比蒸馏水对照明显延长瓶插寿命6 d,使切花鲜样质量、蛋白质含量和相对电导率变化比较慢,适于龙船花瓶插保鲜。     

Salicylic acid and jasmonic acid treatments for potentially extending the longevity of cut Acacia holosericea foliage

Acacia holosericea is a novel cut foliage line with a short vase life. Postharvest application of salicylic acid (SA) can extend the vase life of cut flower. SA is a host defence inducer, as is jasmonic acid (JA). SA and JA were compared as vase solution additives for A. holosericea. Three experiments were conducted that also compared these two chemicals with H⁺ and Cu²⁺ as known vase life extending additives. Vase solutions containing SA at 0.5, 1.5, and 2.5 mM gave ~1.3- to 1.5-fold vase life extensions as compared with the distilled water (DW; control). Provision of Cu²⁺ and JA at 0.5 mM in vase solutions also prolonged vase life by ~1.3-fold as compared with DW. The positive effect of SA tended to be greater than that of JA, but was inferior to that of Cu²⁺ at the same concentration. However, trend differences among these treatments were not statistically significant. Cut A. holosericea foliage stems treated with SA and JA exhibited higher relative fresh weight (RFW) and vase solution uptake rates as compared with DW. Overall, SA and JA evidently extended the vase life of cut A. holosericea foliage by inhibiting water loss and maintaining RFW during the vase period.     

Temperature,ethylene and the postharvest performance of cut snapdragons (Antirrhinum majus)

The effects of temperature and ethylene on the quality of snapdragon flowers (Antirrhinum majus L. cvs. ‘Potomac Pink’ and ‘Rocket’) after harvest were investigated. The flowers were stored dry or wet at 6 temperatures ranging from 0 to 12.5 °C for 5 days. Vase life and gravitropic bending were measured at 20 °C after storage. Respiration rates of flowers at 8 different temperatures (0, 2.5, 5, 7.5, 10, 12.5, 15 and 20 °C) were measured continually using a computerized system. The respiration of cut snapdragon flowers increased exponentially as the temperature increased from 0 to 20 °C, with a mean Q₁₀ of 2.6. The vase life of flowers of the ‘Potomac Pink’ cultivar stored dry at 0 °C was 10.8 days, similar to that of freshly harvested controls (10.6 days), and 4.4 days longer than that of flowers stored at 7.5 °C. When spikes were placed horizontally at 20 °C, growth became negatively gravitropic within 20 min. Bending was significantly higher than controls (stored vertically) in all flowers stored horizontally at temperatures above 5 °C. Vase life of flowers stored for 5 days at a range of temperatures then placed in an interior environment was directly correlated with respiration rate at the storage temperature. Wet storage of cut snapdragon flowers reduced the loss of quality at storage temperatures above 5 °C but the vase life of flowers stored in water at 12.5 °C was less than half that of flowers stored dry at 0 °C. Ethylene treatment caused 100% floret abscission which was prevented by pre-treatment either with 1-methycyclopropene (1-MCP) or with silver thiosulfate (STS), but neither of these inhibitors prevented gravitropic bending.