Analysis of sucrose metabolism during petal growth of cut roses

To clarify the mechanism of flower opening, we investigated sucrose metabolism in rose petals using attached and detached flowers. The petal fresh weight of sucrose-treated detached flowers was lower than for attached flowers, and hexose levels of these detached-flower petals were also lower. Invertase activities in attached flowers increased markedly during petal growth, but these activities in detached flowers decreased, even when detached flowers were treated with sucrose. These different invertase activities might be the cause of the different growth between attached flowers and sucrose-treated detached flowers. Our results suggest that inducing invertase activity in postharvest conditions might be important for the quality of some rose cultivars.     

Methyl jasmonate treatment promotes flower opening of cut Eustoma by inducing cell wall loosening proteins in petals

Establishing the technique for controlling the rate of cut flower opening is important to maintain appropriate cut flower supplies to meet consumer demand. Cut flowers of Eustoma grandiflorum (Raf.) Shinn. were held in a vase solution containing (±)-abscisic acid (ABA), 6-benzylaminopurine (BA), gibberellic acid-3 (GA), methyl jasmonate (MeJA) or 1-naphthaleneacetic acid (NAA) at 100 μM. MeJA accelerated flower opening. Only the timing of flowering was earlier, and there was no change in maximum flower diameter at the fully open stage. Expansin and xyloglucan endotransglycosylase/hydrolase (XTH), regarded as cell wall loosing proteins, participate in petal growth from bud stage to the fully open stage in Eustoma. MeJA also accelerated the expression of EgEXPA2, EgEXPA3 and EgXTH1 mRNA and the accumulation of expansin and XTH protein in petals. Meanwhile, the acceleration of both flower opening and expression of these genes was not observed by ABA, BA or GA treatment. It was proposed that early flower opening by JA treatment resulted from petal cell wall loosening by accelerated expression of expansin and XTH.     

黄兰(Michelia champaca L.)花开放和衰败过程中生理生化指标的变化

为了研究瓶插黄兰(Michelia champaca L.)花开放和衰败过程中的生理生化反应。以黄兰不同开花阶段的花瓣为材料,瓶插观察其外部形态特征变化,测其超氧化物歧化酶(SOD)、过氧化物酶(POD)和可溶性蛋白含量的变化。结果表明,黄兰切枝单花平均瓶插寿命为8.5天。花朵开放和凋谢过程中,花瓣中SOD活性呈现先上升后下降趋势,盛花期活性最强;POD活性在整个过程中持续上升;可溶性蛋白含量在开花前期逐渐升高,显色期后则快速下降。抗氧化酶活性的下降是黄兰花衰败的生理原因之一。     

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

The naturally short vase-life of cut rose flowers, leads to difficulties with long-distance transportation and subsequent marketing. This study was conducted to determine whether application of salicylic acid (SA) pre- and postharvest could improve vase-life of cut rose flowers of the ‘Black Magic’ variety. Aqueous solutions of 50-200 μM salicylic acid were sprayed on roses grown in a controlled greenhouse about two weeks before harvest and flowers were cut and kept in a vase solution of SA (50-400 μM) to examine SA effects on the vase-life, flower development and senescence, increase/decrease of relative fresh and dry weight, vase solution uptake and activity of an antioxidant enzyme, catalase (CAT). All of these attributes were positively affected by SA treatment. The vase solutions containing SA showed a significant increase in cumulative uptake, relative fresh weight, and CAT activity. Generally, CAT activity in intact and cut flowers decreased during the flower bud development with the lowest activity present at petal senescence. However, SA retarded the decrease of CAT activity during senescence both in flowers and leaves compared to the water control. Postharvest SA application prolonged vase-life in cut rose flowers by improving the reactive oxygen species (ROS) scavenging capacity related to CAT activity and by better regulation of the water balance.     

Postharvest water relations in cut rose cultivars with contrasting sensitivity to high relative air humidity during growth

A constant high relative air humidity (RH) during cultivation can strongly reduce the vase life in some cut rose cultivars. We studied three contrasting cultivars in their tolerance to high RH in order to analyse in detail the water relations during postharvest and better understand this genotypic variation. Plants were grown at moderate (60%) and high (95%) RH, and cut flowers were placed in water immediately after cutting. Flowers of cv. Pink Prophyta grown at high RH did not open throughout vase life, while flower opening of cvs. Frisco and Dream was not affected by preharvest RH. Cultivation at high RH resulted in about 80% shorter vase life in Pink Prophyta, whereas in Dream and Frisco the negative effect was considerably smaller (15 and 9% shorter vase life, respectively). The shorter vase life and reduced flower opening of cut roses grown at high RH was due to a higher rate of transpiration both in the light and dark periods. It was found that the leaves of Pink Prophyta grown at high RH could partly close their stomata upon lowering of the water potential or when flower stalks were fed with abscisic acid, but stomata remained far more open than in leaves grown at moderate RH. The RH during cultivation did not affect stem hydraulic conductivity and its recovery after air emboli induction. Preventing vascular occlusion largely alleviated the high-cultivation-RH effect on vase life and flower opening, showing that the effect of high-cultivation-RH becomes only important if water uptake is limited.     

调控月季开花及衰老过程机制的研究进展

月季在历史上不同国家都具有高度的象征意义和文化价值。月季被广泛用作园林观赏植物,切花,并用于香水的精油生产和化妆品行业。月季的开花和衰老的过程仍是园艺学未解决的问题,调节这些过程的机制也有待阐明。本研究从月季开花和衰老过程中的生理机制和遗传学机制方面展开了综述,探讨了影响月季开花和衰老过程的生理学和遗传学因素,重点分析了月季花衰老过程中激素、水分代谢、糖代谢、呼吸作用、抗氧化系统等生理过程的变化,并针对未来月季切花领域的育种方向提供一些思路。     

不同抗蒸腾剂对月季切花保鲜的影响

本文对几种抗蒸腾剂应用于月季切花保鲜的保鲜效果进行了研究,结果表明：抗蒸腾剂Vaporgard稀释至1：70浓度后喷洒在月季切花表面,可延长月季切花的保鲜期;抗蒸腾剂wiltpruf易导致白色花系的月季切花产生花朵变色,因而不适用于白色花系的月季切花保鲜;在实验设定的浓度内,抗蒸腾剂Transfilm未找寻到合适的适用于月季切花保鲜的浓度,其最适浓度有待下一步继续实验确定;外源ABA做为月季切花保鲜剂使用时,其最佳的喷施浓度为0.01g/L。     

Ca2+参与NO对切花月季瓶插期间乙烯合成的调控

分别用0.1 mmol?L-1 SNP（NO供体）、0.1 mmol?L-1 SNP+0.3 mmol?L-1的TFP（CaM）、0.1 mmol?L-1 SNP+10 mmol?L-1的TFP（Ca2+螯合剂）、6 mmol?L-1 Ca2+、6 mmol?L-1 Ca2++0.05 mmol?L-1的PTIO（NO清除剂）处理切花月季‘Kardinal’,研究切花瓶插期间内源乙烯的生物合成变化以及Ca2+在NO对切花月季瓶插期间乙烯合成调控中的作用。结果表明：Ca2+处理能提高月季瓶插前期花瓣中的NOS活性,保持了花瓣中的NO的较高水平,减缓切花瓶插后期NOS活性的升高,进一步研究表明,Ca2+螯合剂EGTA和CaM的抑制剂TFP处理却可使花瓣中的ACS和ACO活性升高,ACC的含量增加,从而加速了乙烯的生物合成;同时,NO的清除剂PTIO处理也可以抑制由于Ca2+处理导致的ACS和ACO的活性降低以及乙烯合成底物ACC的含量下降。因此,Ca2+和CaM可能参与了NO对切花瓶插期间乙烯的合成调控及其信号转导。     

苯扎溴铵预处理对切花菊保鲜的影响初探

为防止Ag+污染环境,开发适宜于切花菊运输前的不含Ag+的预处理剂及预处理方法十分必要。笔者用不同浓度(0~2000 ml/L)无银杀菌剂——苯扎溴铵对切花菊‘神马’的鲜切花进行了不同时间(0~24h)的预处理,然后插入盛有自来水的瓶内,放在温度为20~25℃室内,调查保鲜效果。与其他预处理相比,在100 ml/L溶液预处理3h,瓶插后鲜重一直呈缓慢上升趋势;6d后,极少数叶片发生萎蔫,叶片黄化速度也很缓慢,约90％的叶片12d后还可以保持新鲜;花蕾开放速度也缓慢,15d后仅有50％的花蕾开花,且花瓣挺阔,无枯萎迹象,而且茎干挺直,不弯颈;保鲜效果明显高于其他的预处理。由此可见,使用100 ml/L的苯扎溴铵溶液对菊花鲜切花进行3h的预处理,对其贮运有良好的保鲜效果。     

The effects of 1-MCP in cyclodextrin-based nanosponges to improve the vase life of Dianthus caryophyllus cut flowers

The present research investigated the effects of a non-volatile formulation of 1-methylcyclopropene (1-MCP) embedded in different cyclodextrin (CD)-based nanosponges (NSs) to extend the postharvest longevity of an ethylene-sensitive carnation cultivar. Cut flowers of Dianthus caryophyllus L. ‘Idra di Muraglia’ were treated with α- and β-CD-based nanosponge-1-MCP complexes (α- and β-NS complexes) in tap water to achieve two different concentrations of active ingredient (0.25 and 0.5 μL L^?1). Treated flowers were compared to cut stems exposed to equivalent concentrations of volatile 1-MCP as well as a tap water control with or without pure α- and β-NS. Identical nanoporous compounds were applied by perfusion to yield a total of 15 treatments. Twenty-four hours after the treatments were applied, the cut flowers were exposed to exogenous ethylene (1 ± 0.2 μL L^?1) for 24 h. The postharvest carnation flower and leaf quality in addition to ethylene production levels were determined daily (beginning 24 h after treatment). None of the α-NS complex applications statistically improved the vase life of cut flowers; however, β-NS complexes were effective in preventing senescence, reducing ethylene production (measured at nearly nil after 11 d), and maintaining original petal color longer. These results were particularly strong at the lowest concentration (0.25 μL L^?1) of β-NS complex. Overall, this method promoted cut flower longevity (loss of ornamental value after 14.7 d; complete damage at day 18.5) better than the commercial 1-MCP gaseous application method.     

茉莉酸甲酯处理对采后杏果实品质的影响

为研究不同浓度茉莉酸甲酯(MeJA)处理对采后杏果实品质的影响,分别采用0、10、100μmol/L茉莉酸甲酯处理杏,定期测定其硬度、腐烂指数、可溶性固形物(TSS)含量、可滴定酸(TA)含量、多酚氧化酶(PPO)活性、过氧化氢酶(CAT)活性和过氧化物酶(POD)活性。结果表明:MeJA处理可提高贮藏期间杏果实的CAT活性,抑制POD和PPO活性,同时降低果实的腐烂,在延缓果实软化速度的同时还提高了果实的风味和品质,对杏果TSS含量无太大影响。其中10μmol/L MeJA处理对采后杏果实的保鲜效果最佳。     

Petal blackening and lack of bud opening in cut lotus flowers (Nelumbo nucifera): Role of adverse water relations

Lotus flowers (Nelumbo nucifera Gaertn.) are commercially sold as closed buds. When placed in water the buds fail to open and the outer petals show rapid blackening. We investigated whether this is due to adverse water relations. Placing a plastic bag over the flower head delayed petal blackening, indicating that it was induced by early water stress. This treatment did not result in bud opening. A rapid occlusion of the stem xylem was found. Four possible causes of this occlusion were investigated:air uptake into the xylem, microorganisms in the vase solution, a plant-induced effect, and exuded latex. Preventing the uptake of air into the stem ends did not affect water uptake. Inclusion in the vase water of antibacterial compounds, or antioxidants that inhibit the plant-induced xylem blockage in other species, similarly did not alleviate the xylem occlusion. Cut stems exuded copious latex, close to the opened xylem conduits. Latex exudation was prevented by cutting under water, allow the latex to flow out, and cut again in air, within 1 cm from the previous cut. This treatment did not promote water uptake of the cut stems. A pulse treatment with citric acid also reduced latex flow, but also did not prevent the decrease in water uptake. Treatment with ethephon or GA₃ delayed the xylem occlusion, which suggests that it is induced by the plant itself. Only GA₃delayed petal blackening. None of these treatments promoted flower opening. It is concluded that adverse water relations are a cause of early petal blackening in cut lotus, but is not a cause of the lack of bud opening. The adverse water relations are apparently due to a plant-induced xylem occlusion which is different from those studied thus far in other species.     

保鲜剂对菊花切花衰老过程中生理变化的影响

以大花菊“神马”为材料,利用不同保鲜剂配方对其在保鲜期长短和切花保鲜过程中相关生理指标进行测定,结果表明,2号保鲜剂(去离子水+ 0.03%阿斯匹林+30g/L蔗糖)中切花的花期延长至30天;不同保鲜剂对保鲜过程叶片和花瓣的各项生理指标变化不同,叶片和花瓣的可溶性糖含量较高,可溶性蛋白和SOD变化趋势一致,丙二醛含量趋势不稳定,而叶片和花瓣POD同工酶含量变化趋势相反。研究结果可为菊花切花过程各中保鲜剂的选择提供理论基础,为菊花切花的长短距离运输提供理论依据。     

Effects of ethylene, pollination, and ethylene inhibitor treatments on flower senescence of gentians

Flower senescence of the potted gentian (Gentiana scabra) ‘Shinbisei’ was investigated in relation to ethylene sensitivity and production. ‘Shinbisei’ flowers were used for all experiments except for those with inflorescences. Exposure to ethylene at 0.5 μL L⁻¹ or higher concentrations for 24 h markedly accelerated flower senescence, indicating that G. scabra flowers are highly sensitive to ethylene. Treatment with 0.2 or 0.5 mM silver thiosulfate complex (STS) and 2 μL L⁻¹ 1-methylcyclopropene (1-MCP), ethylene action inhibitors, and 50 mM α-aminoisobutyric acid, an inhibitor of 1-aminocyclopropane-1-carboxylate (ACC) oxidase, did not delay flower senescence. However, treatment with 1 mM l-α-(2-aminoethoxyvinyl) glycine, an inhibitor of ACC synthase, slightly delayed flower senescence. Pollination significantly accelerated petal senescence of G. scabra flowers. Ethylene production of petals, gynoecium, and stamens in unpollinated flowers slightly increased during senescence. Pollination significantly increased ethylene production of petals, gynoecium and stamens 1 day after pollination. To clarify whether 1-MCP delays senescence of cut gentian inflorescences, cut G. scabra ‘Yuki-hotaru’, G. scabra × Gentiana triflora ‘Aoi-kaze’, and G. triflora ‘Koharu’ inflorescences with various stages of flowers, including buds with colored petals, were treated with 2 μL L⁻¹ 1-MCP for 24 h. 1-MCP treatment delayed flower wilting of cut inflorescences of ‘Aoi-kaze’ and ‘Yuki-hotaru’ more than that of ‘Koharu’, suggesting that there is species variation in the effect of 1-MCP in delaying flower senescence of cut gentian inflorescences.     

Effects of phosphine fumigation on postharvest quality of four Chinese cut flower species

Chrysanthemum (White, Yellow, and Daisy), carnation (Master and Barbara), rose (Carola, Black magic, Diana, Champagne, and Avalanche), and Chinese rose (Golden Medallion, Diplomat, Marina, and Athena) are the main Chinese cut flower species produced for exportation. Cut flowers infested with quarantine pests need methyl bromide (MB) fumigation to satisfy phytosanitary requirements of importing countries. Phosphine (PH₃) is a potential alternative to methyl bromide. Development of phosphine as a phytosanitary treatment requires information regarding its phytotoxicity to cut flowers. Therefore phosphine fumigation at 24 °C and 2 °C was investigated to evaluate its effects on the postharvest quality of cut flowers. Phosphine fumigation for 6 h with dosages as high as 12.2 mg L⁻¹ at 24 °C produced no adverse effects on flower color, diameter, vase life, and other damage indices (DI) for all cultivars. However, different adverse effects on some cultivars were observed after 12 d fumigation at 2 °C. There were significant changes for color values of Carola, Black magic, Diana, Champagne, Avalanche, and Diplomat; significant decrease in flower diameter and vase life of Diana, Champagne, and Avalanche at 3.04 mg L⁻¹, white Chrysanthemum and Diploma at 1.52 and 3.04 mg L⁻¹; significant increase in DI of Champagne and Avalanche at 3.04 mg L⁻¹, and White chrysanthemum, Diana, and Diploma at 1.52 and 3.04 mg L⁻¹. In combination with information on phosphine toxicity to insect pests at ambient and low temperatures in the literature, it is suggested that phosphine fumigation could be a viable replacement of MB fumigation for quarantine treatment of these four cut flower species.     

百合切花衰老过程中生理变化

以百合品种“新铁炮”为材料，研究切花花瓣上部在衰老过程中，含水量、可溶性蛋白、糖类、保护酶活性的变化。结果表明：衰老过程中，百合切花花瓣上部含水量4d时开始迅速下降；丙二醛迅速上升；可溶性蛋白含量和SOD活性前期上升后期下降；可溶性总糖、果糖和蔗糖含量均下降。     

化学药剂处理对蓖麻性别的影响

为明确不同浓度的化学药剂对蓖麻性别的影响,本试验以蓖麻两性系（E09004、E09009和E09002）和E09002单雌系为材料,分析了喷施不同浓度的GA3、NAA、乙烯利、6-BA和AgNO3对蓖麻雌雄花率的影响。结果表明：100 mg/L GA3有利于蓖麻雌花的形成,250 mg/L GA3则有利于雄花的分化,前者表现为雌花率上升,后者表现为雌花率降低;NAA和6-BA使雌花率增加,出现了纯雌株;乙烯利有利于雄花的分化,一定浓度的乙烯利可使两性株雄性化;AgNO3促雄效果明显,使两性株雄花率增加,单雌株出现少量雄花;同时试验还获得少数花性特殊（如全雄、纯雌）的材料。本研究为蓖麻的性别逆转诱导、单雌材料的繁殖及性别分化研究提供参考。     

营养物质对延长鲜切玫瑰观赏时间的研究

玫瑰切花作为世界四大鲜切花之一,在花卉市场占有的比重较大,保鲜液的不合理使用将会促进鲜花的过早开放,因此对鲜切花保鲜液的研究也越来越受到人们的重视。设计正交实验方案,用不同配比营养物质的瓶插液处理玫瑰切花,通过对玫瑰切花花枝鲜质量、花蕾直径大小、叶绿素含量、可溶性糖含量和瓶插寿命进行观察、对比测定,选择出一种比较理想的瓶插液。结果表明,NaCl对切花玫瑰的观赏寿命起着主控作用,A3B3C1为最优营养液配比(青霉素20mg/L,N:P:K(Ca)10mL/L,NaCl0.5g/L),对玫瑰切花的观赏价值及瓶插寿命均有一定程度的提高。     

Effects of ethylene on volatile emission and fragrance in cut roses: The relationship between fragrance and vase life

The relationship between fragrance and vase life and the role of ethylene on volatile emission in cut rose flowers was investigated. No relationship was observed between the amounts of volatile compounds emitted and vase life when fragrant and non-fragrant rose cultivars were compared. Neither ethylene production nor respiration rate of flowers was directly related with vase life. Volatile production during vase life was differential and independent among volatiles originating from different biosynthetic groups. Ethylene did not play a role in the regulation of volatile emission in rose flowers. Endogenous ethylene production was very low in most of the cultivars and did not show autocatalytic production trends. Volatile emission patterns during vase life did not parallel endogenous ethylene production. Exogenous ethylene exposure had differential effects among all cultivars, regardless of the fragrance of the flower. Fragrant cultivar ‘Osiana’ was highly sensitive to exogenous ethylene, with petals abscising within 24 h of ethylene (1 μL L^?1) exposure while other fragrant cultivars ‘Erin’ and ‘Lovely Dream’ had low ethylene sensitivity. Volatile production was unaffected by exogenous ethylene. The results of this study indicate that volatile emission in cut roses is not regulated by endogenous or exogenous ethylene and occurs independently of petal senescence and/or abscission. These results provide a better understanding of the complexity of volatile emission in rose flowers.