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.     

Longevity of Epidendrum ibaguense flowers as affected by pre-loading treatments and vase solution

Summary

Post-harvest longevity of Epidendrum ibaguense cut flowers was maximum when treated for 6 h with 1 g m^–3 Ethylbloc^® [0.14% 1-methylcyclopropene; 1-MCP] followed, or not, by pulsing with 200 g l^–1 sucrose for 12 h. This extended the vase-life from 5.5 d to at least 11 d. Cut inflorescences pulsed with 2.0 mM silver thiosulphate (STS) had reduced abscission of flowers, similar to the effect of 1-MCP. When inflorescences were pulsed with 200 g l^–1 sucrose alone for 12 h, no effect was observed on the vase-life of the flowers. Flowers kept in a vase solution containing 20 g l^–1 sucrose, 150 mg l^–1 citric acid, and 200 mg l^–1 8-hydroxyquinoline citrate did not influence the longevity of 1-MCP or STS pre-treated flowers, but the vase solution had a small influence on retarding abscission compared with flowers kept in distilled water. Adding 0.2 mM STS to the vase solution improved vase-life 1.74- and 1.45-fold compared with the longevity of flowers kept in distilled water or in vase solution alone, respectively. The presence of 0.3 mM AgNO₃ alone, or mixed into the vase solution, had no affect on the vase-life of the flowers.     

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.     

纳米银对瓶插月季切花乙烯作用的拮抗效应

 以月季‘影星’（Rosa hybrida‘Movie Star’）切花为试材,用5、10和30 mg · L^-1纳米银（nano-silver,NS）溶液,0.5 mmol · L^-1硫代硫酸银（silver thiosulfate,STS）溶液和去离子水（对照）分别预处理花枝（长为25 cm）基端2 h后再移至去离子水中瓶插,之后用10 μL · L^-1外源乙烯处理24 h,观测切花瓶插期间的观赏品质,瓶插寿命,花径和花枝鲜样质量等指标的变化。结果表明：乙烯处理可加快切花失水凋萎及叶片脱落,并抑制花朵开放,而NS处理可显著减轻乙烯处理的不利影响,其中以30 mg · L^-1 NS处理效果最佳,该处理月季切花的瓶插寿命比乙烯处理延长7 d。另外,取月季切花的花朵（带5 cm花茎,无叶）进行上述试验,进一步证实乙烯处理可抑制花朵开放,而NS处理可显著减轻乙烯对花朵开放的抑制作用。     

谷胱甘肽对切花月季‘Samantha’失水胁迫耐性的影响

采用外源谷胱甘肽（GSH）及其生物合成关键酶γ–谷氨酰半胱氨肽合成酶（γ-ECS）的专一抑制剂丁胱亚磺酰胺（BSO）分别处理切花月季‘Samantha’花枝基部,以提高或降低花瓣中的GSH含量,研究GSH对月季切花失水胁迫耐性的影响,以及花瓣中抗坏血酸–谷胱甘肽（AsA-GSH）循环对失水胁迫的响应。结果表明：提高花瓣中GSH的含量,明显提高了失水胁迫24 h后切花的复水率,延长了瓶插寿命;相反,BSO预处理降低了花瓣中的GSH含量,从而降低了切花的失水胁迫耐性。GSH预处理在明显提高失水胁迫和复水期间花瓣中GSH总含量和还原型GSH含量的同时也提高了抗坏血酸（AsA）的含量;AsA-GSH循环中两个关键酶抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR）的活性也明显高于胁迫对照,并且MDA的含量明显降低。BSO预处理则产生相反的效果。这些结果表明,GSH能够通过提高AsA-GSH循环的抗氧化能力来增强月季切花的失水胁迫耐性。     

Citric acid,sucrose and Cu2+ as potential vase treatments for cut Acacia holosericea G. Don foliage stems

The short vase life of Acacia holosericea cut stems needs to be improved before they are marketable as cut foliage for floral arrangement. The effects of citric acid, Cu²⁺ and sucrose were investigated for their efficacy in postharvest treatments to extend vase life of the cut stems. Five experiments were conducted involved combinations of citric acid either with Cu²⁺ or sucrose. Vase life, relative fresh weight (RFW), and vase solution uptake were measured as indicators of cut stem quality. The effect of Cu²⁺ alone was shown to be consistently superior in improving vase life by up to 1.9-fold as compared with deionised water control. Citric acid had a smaller effect than Cu²⁺ and did not act synergistically with Cu²⁺. Sucrose on its own or in combination with citric acid did not improve vase life significantly; instead sucrose promoted early wilting or desiccation of the cut foliage.     

Water loss and postharvest characteristics of cut roses grown at high or moderate relative air humidity

Single node cuttings with one mature leaf were taken from the rose cv. Baroness and rooted in water culture. The rooted stems were kept in water culture and subjected to one of the two levels of relative air humidity (RH) (high: 90%, moderate: 70%) in climate chambers. Morphological characteristics, dry weight (DW), osmotic concentration, hemicellulose, cellulose and lignin content in the pedicel and vase life behavior were studied, as well as water loss. Only negligible differences in growth and morphology were found. No clear difference in lignin, hemicellulose and cellulose content in pedicels was found between moderate and high RH grown roses. Uncontrolled water loss was characteristic for leaves from high RH roses. Base treatment with AgNO₃ improved vase life of high RH roses from 7 to 12 days. Moderate RH roses lasted on average 15.5 days, and vase life was only slightly improved with the use of AgNO₃. Preservative solutions caused crispy areas between the veins and brittle leaves on roses grown at high but not at moderate RH. A 10% lower osmotic concentration in leaves and flowers was found in roses grown at high RH, as compared to moderate RH. It is concluded that the shorter postharvest life of high RH flowers is mainly due to malfunctioning stomata.     

抗坏血酸提高月季切花失水胁迫耐性与增加APX活性的关系

 以‘Samantha’品种为试材, 确定了适宜的抗坏血酸(AsA) 预处理浓度, 探讨了AsA和抗坏血酸过氧化物酶(APX) 抑制剂(对氨基酚, β-aminophenol) 预处理对花瓣中相对电导率、AsA含量以及APX活性的影响。与未经失水胁迫的切花月季相比较, 失水胁迫处理抑制切花的开放进程, 缩短了瓶插寿命。AsA 1 000 mg·L ^{- 1}预处理可有效地改善花朵的开放状况, 显著降低花瓣中相对电导率的增加, 明显提高花瓣中AsA的含量和APX活性。500 mg·L ^{- 1} β-aminophenol预处理则起到相反的效应。结果说明,AsA对‘Samantha’月季切花失水胁迫耐性的改善与花瓣中APX活性的提高相联系。     

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.     

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.     

Copper distribution and ionic form effects for postharvest treatments of cut Acacia holosericea stems

A short postharvest life is the major constraint associated with cut Acacia flowers and foliage. Treatment with CuSO₄ (Cu²⁺) has previously been shown to improve the longevity of cut Acacia holosericea stems. Towards refining the treatments, a range of Cu²⁺ and Cu⁺ salts were assessed for relative efficacy in improving vase life and water relations of A. holosericea. Five hour pulses with the Cu²⁺ salts CuSO₄, CuCl₂, (CH₃COO)₂Cu and Cu(NO₃)₂ at 2.2 mM gave equally longer vase lives by ∼2.5-fold over deionised water (DIW) and standard tap water (STW) controls. The same Cu²⁺ salts at 0.5 mM in the vase solution also gave significantly (P < 0.05) improved vase life, relative fresh weight and water uptake compared to the DIW control. For Cu²⁺ versus Cu⁺, optimum concentrations with Cu²⁺ could not be directly compared due to the low solubility of the Cu⁺ salt CuCl. However, Cu⁺ from CuCl at 0.415 mM also had positive effects on vase life compared to the DIW control. Thus, both Cu²⁺ and Cu⁺ treatments can enhance vase life parameters for cut A. holosericea foliage. The benefits were irrespective of the counter ion and, thus, Cu²⁺ and Cu⁺per se were responsible. The most effective Cu²⁺ pulse treatment decreased stomatal conductance of phyllodes initially, but did not cause sustained stomatal closure. Cu accumulated to greater levels in basal stem and phyllode tissues than in upper stem and phyllode tissues of cut A. holosericea stems. Possible mechanisms of Cu²⁺/Cu⁺ action are discussed.     

Factors affecting the vase life of fronds of maidenhair fern

Cut fronds of maidenhair fern (Adiantum raddianum), which last only 3 days in DI water, were used as a model system to study factors affecting the vase life of cut greens. Solutions containing 25 mg 1^?1 Ag⁺ increased vase life 5-fold. Other biocides (8-hydroxyquinoline citrate, a quaternary ammonium compound, or 8-hydroxyquinoline citrate + NaOCl) had little effect on vase life, while inhibitors of ethylene (C₂H₄) production (Co²⁺, aminooxyacetic acid) increased vase life. Wound C₂H₄ production by the cut ends of the stipes declined during the first 2 h after cutting. The hypothesis that this C₂H₄ is the cause of the brief vase life of maidenhair fern is discussed.     

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.     

Stomatal regulation and xylem cavitation in Clementine (Citrus clementina Hort) under drought conditions

Summary

In many trees species, a strong relationship exists between stomatal closure and the onset of cavitation in xylem vessels. This relationship was investigated in a Citrus species. Young potted ‘Clementine’ (Citrus clementina Hort ‘Clementine’) grafted on ‘Carrizo Citrange’ (Citrus sinensis × Poncirus trifoliata) or ‘Trifoliate Orange’ (Poncirus trifoliata Raf), and grown under greenhouse conditions, were submitted to periods of drought by withholding irrigation. Pre-dawn water potential, leaf stomatal conductance, plant transpiration, the degree of xylem embolism, and xylem vulnerability curves were measured. Transpiration and stomatal conductance were reduced to a minimum value when the pre-dawn water potential reached -1 MPa. This value corresponded to the threshold pressure below which cavitation was induced. Higher intensities of water stress provoked more cavitation, but the degree of xylem embolism, as measured by percentage loss of conductivity, always remained below 50%. ‘Clementine’ is therefore vulnerable to embolism, but early stomatal regulation prevents the occurrence of embolism. Under severe water stress, ‘Clementine’ is able to maintain functional xylem vessels, which probably enhances its survival during periods of intense drought, and favours its recovery. This suggests that xylem cavitation is a key process in understanding the response of Citrus to drought and, hence, is a promising criterion by which to screen for more drought-tolerant genotypes.     

Effect of pre- and postharvest salicylic acid treatment on physio-chemical attributes in relation to the vase life of cut rose flowers

With the aim of extending the vase life of cut rose flowers, we investigated whether the application of salicylic acid (SA), pre- and postharvest, could improve this. For this purpose, two individual trials were conducted, using a completely randomised design, with three replications. In the first trial, aqueous solutions of 0, 0.5, 1.0 and 1.5 mM SA were sprayed on roses grown in a controlled greenhouse once the flower buds had appeared, and the second stage was performed two weeks before harvest. The preharvest SA application at 1.5 mM concentration prolonged the vase life of cut roses by improving membrane stability, and decreasing the lipid peroxidation properties. In the second trial, continuous exposure to (0, 0.5, 1.0 and 1.5 mM), and pulses of (0, 5, 10 and 15 mM), SA significantly extended the vase life. Flowers treated with 1.5 (continuous exposure) and 15 mM (pulse) SA showed a significant decrease in weight loss, and antioxidant activity increased, compared to the control solution, but the flowers in the control solution indicated an increase in weight loss. The results show that pre- and postharvest SA application prolonged the vase life of cut roses through improving CAT and POD activity, and decreasing lipid peroxidation.     

切花月季‘萨蔓莎’和‘加布里拉’失水胁迫耐性的差异

  不同失水胁迫条件下的研究结果表明: 切花月季耐失水胁迫品种‘萨蔓莎’和不耐失水胁迫品种‘加布里拉’的瓶插寿命缩短百分比、鲜样质量损失率、相对电导率、花朵乙烯生成量都随胁迫程度的增加而增加, 叶片、花朵水势随胁迫程度的增加而下降, 萨蔓莎的变化幅度比加布里拉小。中度失水胁迫的叶片和花瓣SOD、POD 活性高于轻度和重度胁迫。两个品种的叶片气孔阻力没有明显区别。瓶插期间,相同失水胁迫时间, 萨蔓莎复水恢复能力比加布里拉强。讨论了月季切花上述参数与失水胁迫耐性之间的关系。     

Competition for water between inflorescences and leaves in cut flowering stems of Grevillea ‘Crimson Yul-lo’

Summary

Grevillea cv. ‘Crimson Yul-lo’ has large bright red terminal inflorescences on leafy stems and has recognised commercial potential as a cut flower crop. A major limitation is its relatively short vase-life, often terminated by early wilting of the inflorescence despite apparently turgid leaves. An investigation of the water relations of cut Grevillea ‘Crimson Yul-lo’ stems revealed that the water potential of inflorescences on intact stems in vases was significantly higher (i.e., less negative) than that of leaves from day-0 to day-3 of vase-life. Thereafter, the water potential of inflorescences declined more rapidly than that of leaves, accompanied by visible wilting of the tepals and styles of individual florets. Removal of leaves from the stems reduced both water uptake and water loss, and delayed the onset of a negative water balance in the inflorescence. Bagging of entire stems, leaves only, or inflorescences only, with micro-perforated plastic film to reduce transpiration, reducing leaf number to reduce leaf area, or supplying abscisic acid to reduce leaf stomatal aperture, all aided relative fresh weight retention by stems and extended vase-life. Four or six leaves on a stem caused greater loss in inflorescence water content than zero or two leaves. Considered collectively, these findings show that competition for water between the inflorescence and the leaves in cut Grevillea ‘Crimson Yul-lo’ stems contributes to the onset of inflorescence wilting and their short vase-life.     

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。     

Partitioning of photosynthates originating from bent shoots in the arching and high-rack culture systems of cut rose production

The arching and high-rack culture systems were developed and patented by Japanese rose growers. Both culture systems have bent canopies (lower bent shoots). In the arching culture system, shoots sprouting from the crown are harvested as cut flowers. However, the high-rack culture system also has a bent canopy originating from the mother stem (upper bent shoots) and flower stems sprout and is harvested at the top of each mother stem. Partitioning of photosynthates originating from bent shoots in arching and high-rack culture systems of rose production was investigated to elucidate how carbohydrates are re-allocated from the bent shoots in different culture systems of roses. At the flowering stage in both culture systems, 50–70% of ¹³C-photosynthates originated from bent shoots were exported to other parts within 72 h after ¹³CO₂ feeding to the bent shoot. In the arching culture system, photosynthates from lower bent shoots were partitioned mainly to the roots and crown. Similarly, in the high-rack culture system, between 71 and 86% of the exported carbon from the bent shoots were allocated to below the point of bending (roots + crown + mother stems) and only 9–28% was allocated to flowering shoots above the point of bending. In both culture systems, photosynthate translocation from the lower bent shoot directly to flowers was low. Accordingly, bent shoots in rose plants acted as a source of photosynthates, independent of culture system. The height of the bent shoots determined for a great deal in the re-allocation of the photosynthates, and provides a partial explanation for difference in production of cut roses.