Carnation Cultivars Research Articles

Development of an efficient in vitro shoot regeneration method for carnation cultivars using cotyledons with apical shoot meristems

Development of an efficient in vitro shoot regeneration method for carnation cultivars using cotyledons with apical shoot meristems

Resposta de cultivares de cravo suscetíveis à aplicação de tiamina como indutor de resistência à murcha vascular causada por Fusarium oxysporum f. sp. dianthi

Abstract Colombia is one of the main producers of carnations worldwide. However, its production has been affected by vascular wilting caused by the pathogen Fusarium oxysporum f. sp. dianthi (Fod). In previous studies, thiamine has been proposed as a potential resistance inducer for this disease, under greenhouse growth conditions. However, the specific conditions for its application must be studied when applying it under commercial conditions. In this sense, this study aimed to evaluate the effect of the thiamine foliar spray in different concentrations among some susceptible carnation cultivars in response to Fod-inoculation. For this, two in-vivo trials were carried out, using foliar spraying of thiamine as a treatment before inoculation with the pathogen Fod, then measurements of incidence, severity, and the content of phenolic and flavonoid compounds were made. It was found that thiamine application, in the concentrations evaluated, shows a statistically similar decrease in the disease incidence and severity. These results were verified using multivariate statistical analysis. In addition, it was found that the application of thiamine 1 mmol L-1 presents a positive response in reducing the effects of the disease in three susceptible cultivars. The results suggest that thiamine has the potential to be applied as a technique in the integrated management of disease in the productive sector.

Genome sequences of 10 new carnation mottle virus variants.

Here, we report the genome sequences of 10 Carnation mottle virus variants. Six variants originated from a single proprietary carnation cultivar, and four were derived from four different proprietary cultivars. All variants showed nucleotide differences, but the last four did not show any variation at the amino acid level.

Melatonin strongly enhances the Agrobacterium- mediated transformation of carnation in nitrogen-depleted media

With the rising demand for new cultivars of carnation, efficient transformation protocols are needed to enable the bioengineering of new traits. Here, we established a novel and efficient Agrobacterium-mediated transformation system using callus as the target explant for four commercial carnation cultivars. Leaf-derived calli of all cultivars were inoculated with Agrobacterium tumefaciens strain LBA4404 containing the plasmid pCAMBIA 2301 harboring genes for β-glucuronidase (uidA) and neomycin phosphotransferase (nptII). Polymerase chain reaction (PCR) and histochemical assays confirmed the presence of uidA and β-glucuronidase (GUS), respectively in transgenic shoots. The effect on transformation efficiency of medium composition and the presence of antioxidants during inoculation and co-cultivation was investigated. The transformation efficiency was increased in Murashige and Skoog (MS) medium lacking KNO3 and NH4NO3, and also in MS medium lacking macro and micro elements and Fe to 5% and 3.1% respectively, compared to 0.6% in full-strength medium. Transformation efficiency was increased dramatically to 24.4% across all carnation cultivars by the addition of 2 mg/l melatonin to nitrogen-depleted MS medium. Shoot regeneration was also doubled in this treatment. The establishment of this efficient and reliable transformation protocol can advance the development of novel carnation cultivars through molecular breeding approaches.

Genome-Wide Identification of the MYB and bHLH Families in Carnations and Expression Analysis at Different Floral Development Stages.

Carnations are one of the most popular ornamental flowers in the world with varied flower colors that have long attracted breeders and consumers alike. The differences in carnation flower color are mainly the result of the accumulation of flavonoid compounds in the petals. Anthocyanins are a type of flavonoid compound that produce richer colors. The expression of anthocyanin biosynthetic genes is mainly regulated by MYB and bHLH transcription factors. However, these TFs have not been comprehensively reported in popular carnation cultivars. Herein, 106 MYB and 125 bHLH genes were identified in the carnation genome. Gene structure and protein motif analyses show that members of the same subgroup have similar exon/intron and motif organization. Phylogenetic analysis combining the MYB and bHLH TFs from Arabidopsis thaliana separates the carnation DcaMYBs and DcabHLHs into 20 subgroups each. Gene expression (RNAseq) and phylogenetic analysis shows that DcaMYB13 in subgroup S4 and DcabHLH125 in subgroup IIIf have similar expression patterns to those of DFR, ANS, and GT/AT, which regulate anthocyanin accumulation, in the coloring of carnations, and in red-flowered and white-flowered carnations, DcaMYB13 and DcabHLH125 are likely the key genes responsible for the formation of red petals in carnations. These results lay a foundation for the study of MYB and bHLH TFs in carnations and provide valuable information for the functional verification of these genes in studies of tissue-specific regulation of anthocyanin biosynthesis.

ASSESSING THE IMPACT OF INDOLE-3-BUTYRIC ACID (IBA) ON ROOTING EFFICIENCY IN CARNATION (DIANTHUS CARYOPHYLLUS L.) PROPAGATION UNDER PROTECTED CONDITIONS

The study aimed to assess the impact of varying Indole-3-Butyric Acid (IBA) concentrations on the rooting efficacy of Carnation (Dianthus Caryophyllus L.) cuttings within a controlled greenhouse setting. Different concentrations of IBA were applied to selected Carnation cultivars to stimulate root development. The greenhouse environment maintained controlled conditions, regulating temperature, humidity, and light to mimic optimal growth settings. The study focused on observing and analyzing rooting responses, particularly concerning root initiation, elongation, and biomass accumulation. Results indicated a distinct relationship between IBA concentrations and the rooting efficiency of Carnation cuttings. Lower concentrations displayed negligible effects on root development, while moderate concentrations significantly stimulated root initiation and elongation. Surprisingly, excessively high IBA concentrations led to reduced rooting responses, suggesting a hormetic effect on root growth. Morphological assessments highlighted that optimal IBA concentrations fostered vigorous root systems characterized by increased length, number, and mass of roots. This research underscores the pivotal role of precise IBA application in promoting successful rooting of Carnation cuttings, especially in controlled environments. The findings provide crucial insights for refining propagation techniques tailored specifically for Carnations, offering guidance to growers in optimizing IBA concentrations for efficient and sustainable cultivation practices in the floriculture industry. Further investigations delving into the prolonged impacts of IBA on overall plant growth and development would deepen the understanding derived from these findings.

The mutual regulation between DcEBF1/2 and DcEIL3-1 is involved in ethylene induced petal senescence in carnation (Dianthus caryophyllus L.).

Carnation (Dianthus caryophyllus L.) is a respiratory climacteric flower, comprising one of the most important cut flowers that is extremely sensitive to plant hormone ethylene. Ethylene signaling core transcription factor DcEIL3-1 plays a key role in ethylene induced petal senescence in carnation. However, how the dose of DcEIL3-1 is regulated in the carnation petal senescence process is still not clear. Here, we screened out two EBF (EIN3 Binding F-box) genes, DcEBF1 and DcEBF2, which showed quick elevation by ethylene treatment according to the ethylene induced carnation petal senescence transcriptome. Silencing of DcEBF1 and DcEBF2 accelerated, whereas overexpression of DcEBF1 and DcEBF2 delayed, ethylene induced petal senescence in carnation by influencing DcEIL3-1 downstream target genes but not DcEIL3-1 itself. Furthermore, DcEBF1 and DcEBF2 interact with DcEIL3-1 to degrade DcEIL3-1 via an ubiquitination pathway in vitro and in vivo. Finally, DcEIL3-1 binds to the promoter regions of DcEBF1 and DcEBF2 to activate their expression. In conclusion, the present study reveals the mutual regulation between DcEBF1/2 and DcEIL3-1 during ethylene induced petal senescence in carnation, which not only expands our understanding about ethylene signal regulation network in the carnation petal senescence process, but also provides potential targets with respect to breeding a cultivar of long-lived cut carnation.

Water permeability of different aerial tissues of carnations is related to cuticular wax composition.

Cuticular wax protects aerial plant tissues against uncontrolled water loss. To compare the differences among tissues, cultivars, and postharvest stages, we characterized the surface morphology, water permeability, and chemical composition of cuticular wax on the leaf, calyx, and petals of two carnation cultivars ('Master' and 'Lady green') at two postharvest stages. Obvious differences in these characteristics were found among tissues but not among cultivars or postharvest stages. The leaf surface was relatively smooth, whereas convex cells were observed on the petals. The mean minimum conductance of leaves was significantly higher than that of the calyx, followed by that of petals. It ranged between 8.8 × 10-4 m s-1 for 'Lady green' leaves at Stage II and 3.6 × 10-5 m s-1 for 'Master' petals at Stage I. Petal wax contained high concentrations of n-alkanes, whereas primary alcohols dominated in leaf wax. The weighted average chain length (ACL) was higher in petal wax than in leaf wax; it ranged from 19.6 in 'Lady green' leaves to 24.14 in 'Lady green' petals at Stage I. In conclusion, carnation petals are characterized by numerous convex cells on both the adaxial and abaxial surfaces, and their main cuticular wax components, alkanes, have a higher ACL than leaf cuticular wax, which contributes to their higher water barrier property. The results provide further evidence for the association between cuticular chemical composition and the physiological function of the cuticle in blocking water transpiration.

In vitro cell selection and multiplication of Fusarium oxysporum f. sp. dianthi insensitive plants in carnation cultivars Tempo and Raggio-de-Sole

In vitro cell selection and multiplication of Fusarium oxysporum f. sp. dianthi insensitive plants in carnation cultivars Tempo and Raggio-de-Sole

Nano-Selenium in the holding solution promotes rose and carnation vase life by improving both water relations and antioxidant status

ABSTRACT Nano-selenium (nano-Se) is an eco-friendly and inexpensive compound. The potential of including it in the holding solution to stimulate vase life was investigated by conducting two experiments. In the first one, dose-response curves were generated by applying different nano-Se concentrations (0–1 and 0–1.5 µM for rose and carnation, respectively) in the holding solution of three cultivars per species. Nano-Se in the holding solution improved vase life in all cases, besides one carnation cultivar. The optimal concentration was considerably higher in carnation as compared to rose (1–1.5 and 0.25–0.75 µM, respectively), and was cultivar dependent. Nano-Se improved cut flower water balance by enhancing water absorption more than transpiration. In the second experiment, the optimal holding solution nano-Se concentration was employed to evaluate the underlying processes in the two cultivars per species, where vase life was mostly increased. Physiological and biochemical characteristics were assessed in both leaf and petal tissues. Nano-Se ameliorated chlorophyll degradation, electrolyte leakage and lipid peroxidation owing to up-regulation of both enzymatic and non-enzymatic antioxidants. In conclusion, the nano-Se-induced vase life extension was associated with both upgraded antioxidant status and improved water relations, setting it as a low-cost and environmentally-safe agent of prolonging floral longevity.

Effect of Different Type Light and Growing Medium on the Growth and Flowering of Two Cultivars of Carnation (Dianthus caryophyllus L.)

This study was carried out in the greenhouse of the Horticulture Department Nursery, College of Agriculture Engineering Sciences, Duhok University, Kurdistan region, Iraq, for the period from 1st Aug 2020 to 1st Mar 2021, to study the effect of five supplemental light (control, natural light, Incandescent 14, Incandescent 18, mixed 14, mixed 18) hours daily and three growing medium (river soil, river soil + 30% local compost, river soil + 60% local compost) on some vegetative growth and flowering of two cultivars of carnation plant. The best results (fewest days) for the number of days from planting to bud emergence, visible flower colour, and anthesis were obtained when the plants were exposed to mixed light colours or incandescent lamps for a 14-hour treatment, Also this treatments were significantly superior in the other characteristics like plant height, flower length and flower diameter compared to the control. Medium with 60% local compost significantly increased all the studied characteristics compared with other mediums. The Ormea (Red) cultivar was significantly superior to the Moonlight cultivar in all studies of characteristics and was early in day numbers for bud emergence, visible flower colour, and anthesis. All second interactions between the investigated factors had a significant influence in all studied characteristics. In addition, the triple interaction between the three factors had a significant impact on all characteristics, including the least days or fewest days to flower anthesis of the Ormea cultivar when planted on medium containing 60% local compost under incandescent 14h, which took 101.80 days compared 176.27 days, with an early reach of 74.47 days for the control. The Moonlight (white) cultivar required the fewest days, 128.93 days, for a medium containing 60% compost under mixed 14h, which needed 123.93 days, compared to the control, which required 195.87 days with an early flowering rate of 71.94 days.

Response of some carnation varieties to Meloidogyne incognita, Meloidogyne javanica and Meloidogyne arenaria

Carnation is one of the most crucial cut flowers in Turkey. Root-knot nematodes (RKNs) cause significant damage on carnation production and quality. Therefore, determination of response of carnation varieties to RKNs is required for management practices. In this study, four carnation cultivars, Turbo, Betsy, Nirvana and Glaciar, were inoculated with second stage juveniles (J2s) of Meloidogyne incognita, M. javanica and M. arenaria under controlled conditions. Meloidogyne incognita, M. javanica and M. arenaria did not reproduce on Turbo variety. Therefore, Turbo variety was found to be resistant to these nematodes. Nirvana variety was moderately resistant to M. incognita and M. javanica, but highly resistant to M. arenaria. Betsy and Glaciar varieties were susceptible to M. incognita, M. javanica and M. arenaria. Results showed that the response of carnations was different based on root knot nematodes. Determining resistant carnation varieties could be an advantage for the control of RKNs. Resistant carnations could be used to control the RKNs and develop new carnation varieties.

Integrated multi-omic data and analyses reveal the pathways underlying key ornamental traits in carnation flowers.

SummaryCarnation (Dianthus caryophyllus) is one of the most popular ornamental flowers in the world. Although numerous studies on carnations exist, the underlying mechanisms of flower color, fragrance, and the formation of double flowers remain unknown. Here, we employed an integrated multi‐omics approach to elucidate the genetic and biochemical pathways underlying the most important ornamental features of carnation flowers. First, we assembled a high‐quality chromosome‐scale genome (636 Mb with contig N50 as 14.67 Mb) of D. caryophyllus, the ‘Scarlet Queen’. Next, a series of metabolomic datasets was generated with a variety of instrumentation types from different parts of the flower at multiple stages of development to assess spatial and temporal differences in the accumulation of pigment and volatile compounds. Finally, transcriptomic data were generated to link genomic, biochemical, and morphological patterns to propose a set of pathways by which ornamental traits such as petal coloration, double flowers, and fragrance production are formed. Among them, the transcription factors bHLHs, MYBs, and a WRKY44 homolog are proposed to be important in controlling petal color patterning and genes such as coniferyl alcohol acetyltransferase and eugenol synthase are involved in the synthesis of eugenol. The integrated dataset of genomics, transcriptomics, and metabolomics presented herein provides an important foundation for understanding the underlying pathways of flower development and coloration, which in turn can be used for selective breeding and gene editing for the development of novel carnation cultivars.

Carbon nanotubes in the holding solution stimulate flower opening and prolong vase life in carnation

BackgroundCut flower longevity is often limited by adverse water relations or oxidative stress. The potential of single- and multi-walled carbon nanotubes (SWCNTs and MWCNTs, respectively) on prolonging vase life was addressed. Dose–response curves were obtained by applying five concentrations (0–80 mg L−1) of SWCNTs or MWCNTs either once as a foliar spray or continuously in the holding solution of three carnation cultivars. Next, the optimal concentration of either SWCNTs or MWCNTs was employed to evaluate several parameters critical for vase life.ResultsFoliar spray application exerted minor effects on water relations, flower opening and keeping quality. By contrast, including CNTs in the holding solution sustained a positive water balance for a longer period, improved flower opening and prolonged vase life. These effects were similar between SWCNTs and MWCNTs, and were concentration-dependent. The optimal concentration for vase life was higher for MWCNTs as compared to SWCNTs, and for two cultivars as compared to the third one. At optimal concentration, SWCNTs or MWCNTs in the holding solution generally maintained turgidity, and alleviated chlorophyll degradation, electrolyte leakage and lipid peroxidation. These effects were related to increased activation of enzymatic (ascorbate peroxidase, catalase, peroxidase and superoxide dismutase) and non-enzymatic (carotenoids, polyphenols, and flavonoids) antioxidants.ConclusionCNTs in the holding solution were very effective in stimulating vase life through improved water relations and enhanced antioxidant machinery stimulation.Graphical

Efficient Plant Regeneration via Indirect Organogenesis in Carnation (Dianthus caryophyllus semperflorens flore pleno) Cultivars

Abstract Callus induction and plant regeneration are important steps of in vitro plant breeding of ornamental plants. In this study, the effects of different combinations of plant growth regulators (PGRs), promoters, and minerals on callus induction and plant regeneration in different carnation cultivars were studied in a completely randomized design with three replications. For callus induction, 16 different combinations of 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzylaminopurine (BA), 1-naphthaleneacetic acid (NAA), and casein hydrolysate (CH) were studied using in vitro leaf explants. The Murashige and Skoog (MS) medium supplemented with 0.2 mg·dm−3 of 2,4-D and 200 mg·dm−3 of CH showed the highest frequency of callus induction. Among the cultivars, ‘Noblesse’ showed the highest rate of callus induction (91.67%). Regarding regeneration, BA, NAA, silver nitrate (AgNO3), and adenine hemisulfate (As) were used in ten different combinations. The ‘Cameron’, ‘Tabasco’, and ‘Noblesse’ cultivars with 95.24% regeneration percentage showed the highest rate of plant regeneration. Generally, in most cultivars, the highest regeneration rate and shoot number per explant were found in the MS medium supplemented with 3 mg·dm−3 of BA, 0.6 mg·dm−3 of NAA, 5 mg·dm−3 of AgNO3, and 40 mg·dm−3 of As. According to the results, the highest regeneration frequency was obtained when 40 mg·dm−3 of As was added to the medium. Finally, the flow cytometry analysis indicated that there were no significant differences between in vitro regenerated and control plants in terms of DNA ratios.

Vase life and antioxidant status of two carnations (Dianthus caryophyllus L.) cultivars affected by gamma aminobutyric acid (GABA) treatments

Purpose: Carnation (Dianthus caryophyllus L.) is one of the most popular and economically important cut flowers worldwide ranking the third after rose and chrysanthemum. The vase life of many carnation cultivars is short due to sensitivity to ethylene or other factors. This research was performed to study effect of gamma aminobutyric acid (GABA 0.5, 0.75 and 1mM) on postharvest quality of tow famous carnation cultivars viz. Delphi (white) and Dob Pedro (Red). Research method: The experiment was conducted as completely randomized design (CRD) with five replications per treatment. Findings: The results indicated that all concentrations of GABA significantly prolonged the vase life in both cultivars. GABA decreased lipid peroxidation of petal tissue while increased the activity of some antioxidant enzymes such as catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and guaiacol peroxidase (GPX). Polyphenoloxidase (PPO) activity was also decreased in GABA-treated cut flower. Interestingly, both cultivars responded similarly to GABA treatments. The findings also revealed that GABA had antioxidant properties capable of increasing defense ability of the carnation cut flower. Meanwhile, the applied concentration is very critical and should be taken into account. Based on the present findings, the best treatment is GABA at 0.75 mM. Limitations: No limitations were encountered. Originality/Value: The results of this research indicated that GABA had antioxidant properties capable of increasing defense ability of the carnation cut flower. It appears that the applied GABA operates through membrane conservation, increasing the activity of antioxidants enzymes and decreasing PPO activity.

Flavonoid biosynthesis in Dianthus caryophyllus L. is early regulated during interaction with Fusarium oxysporum f. sp. dianthi

Rooted cuttings from two carnation (Dianthus caryophyllus L.) cultivars showing contrasting responses to the vascular wilt caused by Fusarium oxysporum f. sp. dianthi (Fod) were inoculated with this phytopathogen, and some of the biochemical responses associated with flavonoid biosynthesis were investigated in the roots. The resistant cultivar (‘Golem’) showed a significant increase in the levels of phenolic and flavonoid compounds at 48–96 h post-inoculation (hpi) (α = 0.05). LC-MS-based analysis indicated that the flavonoids mainly included flavanol-type glycosides, especially quercetin and kaempferol aglycones. Quantification of the mRNA levels of genes encoding CHS (Chalcone Synthase), CHI (Chalcone Isomerase), FLS (Flavonol Synthase), and the transcription factor MYB11 by using reverse transcription quantitative polymerase chain reaction (RT-qPCR) indicated that the resistant cultivar exhibited higher expression levels of these genes and, therefore, showed more flavonoid accumulation at 96 hpi. The differences in the temporal regulation of the assessed variables during infection support the idea that the early expression of enzymes of the flavonoid biosynthesis pathway in carnation roots is linked to a resistance response to the hemibiotrophic pathogen Fod race 2. The present experimental approach is the first report describing the molecular mechanisms underlying flavonoid biosynthesis in carnation roots during their interaction with Fod.

Mycelium Dispersion from Fusarium oxysporum f. sp. dianthi Elicits a Reduction of Wilt Severity and Influences Phenolic Profiles of Carnation (Dianthus caryophyllus L.) Roots.

The fungal pathogen Fusarium oxysporum f. sp. dianthi (Fod) is the causal agent of the vascular wilt of carnation (Dianthus caryophyllus L.) and the most prevalent pathogen in the areas where this flower is grown. For this reason, the development of new control strategies against Fod in carnation has been continuously encouraged, in particular those based on the implementation of plant resistance inducers that can trigger defensive responses to reduce the disease incidence, even at lower economical and environmental cost. In the present study, the effect of the soil supplementation of a biotic elicitor (i.e., ultrasound-assisted dispersion obtained from Fod mycelium) on disease severity and phenolic-based profiles of roots over two carnation cultivars was evaluated. Results suggest that the tested biotic elicitor, namely, eFod, substantially reduced the progress of vascular wilting in a susceptible cultivar (i.e., ‘Mizuki’) after two independent in vivo tests. The LC-MS-derived semi-quantitative levels of phenolic compounds in roots were also affected by eFod, since particular anthranilate derivatives, conjugated benzoic acids, and glycosylated flavonols were upregulated by elicitation after 144 and 240 h post eFod addition. Our findings indicate that the soil-applied eFod has an effect as a resistance inducer, promoting a disease severity reduction and accumulation of particular phenolic-like compounds.

Nano-silver controls transcriptional regulation of ethylene- and senescence-associated genes during senescence in cut carnations

Flower senescence in three carnation cultivars (‘Koba Kabana,’ ‘Purple Sky,’ and ‘Lufa’) was associated with increased ethylene production in floral tissues (petals and gynoecia). Treatment with silver nanoparticles (NAg) significantly reduced ethylene production in petals and gynoecia and significantly delayed petal senescence compared with that in control (untreated) flowers, as indicated by higher relative fresh weight. Gene expression analyses performed on petals and gynoecia from initial flower opening through senescence indicated that the expression levels of ethylene biosynthesis genes (ACS1 and ACO1) and a petal senescence-related gene (CP1) were significantly higher in control flowers than in NAg-treated flowers. In contrast, the expression level of the petal senescence inhibitor gene CPi was more upregulated in NAg-treated flowers than in control flowers. The expression levels of EIL1/2, ERS2, and EBF1 were significantly higher in control flowers, in which ethylene was highly produced, than in NAg-treated flowers, whereas the expression levels of CTR1 and ETR1 were lower. This indicates that EIL1/2, ERS2, and EBF1 positively regulate and CTR1 and ETR1 negatively regulate the ethylene signal transduction pathway in carnations. In addition, NAg can inhibit the expression of these positive regulator genes in carnations. Therefore, this study suggests that NAg is helpful in significantly repressing ethylene production and delaying petal senescence in carnations via the suppression of ethylene biosynthesis genes, a petal senescence-related gene, and genes positively regulating ethylene signaling in petals and gynoecia.

Scent emissions and expression of scent emission-related genes: A comparison between cut and intact carnation flowers

Although the physiological states of intact and cut flowers are expected to be significantly different, the floral scent emissions of these two conditions has yet to be compared. We compared the scent emissions from intact and cut flowers using carnation (Dianthus caryophyllus L.) cultivars with two different scent-types—a fruity scent based on benzenoid methyl benzoate and a spicy scent based on eugenol. Methyl benzoate or eugenol, which were the principal scent components, always had the highest percentage (> 30 %) in both intact and cut flowers from flower opening to wilting. The total emissions from intact flowers remained at a similar level for approximately 6 days after flower opening, and then gradually decreased with flower senescence. The total emissions from cut flowers were highest on the day of flower opening and then decreased more rapidly than emissions from intact flowers. Furthermore, the duration of noticeable scent of cut flowers was estimated to be shorter than that of intact flowers. The expression of various scent emission-related genes encoding floral volatile benzenoid/phenylpropanoid biosynthesis enzymes, adenosine triphosphate-binding cassette transporters, and MYB transcription factors increased with flower opening and were accompanied by scent emissions. However, the expressions of most of these genes were not affected by cutting, suggesting that the decrease in scent emissions from cut flowers is unlikely due to changes in gene expression. Recently, we reported that cutting accelerates the decrease in sugar content and increases ethylene production in carnation petals, resulting in hastened flower senescence. Therefore, the rapid decrease in scent emissions from cut flowers may be due to a decrease in sugars, which are substrates for the scent components.