Chrysanthemum Flowers Research Articles

Effects of humic acid derived from sediments on the postharvest vase life extension in cut chrysanthemum flowers

Previous research has shown that humic acid can extend the vase life of cut flowers. However, the mechanisms responsible for this effect are unclear. In this study, the physiological mechanisms of foliar humic acid fertilizer on cut chrysanthemum flower postharvest vase life were investigated. Seedlings of chrysanthemum were sprayed with the same volume of distilled H2O, inorganic NPK fertilizer and organic foliar humic acid fertilizer every 15 days (15, 30, 45, 60 days after transplanting).The results showed that foliar application of humic acid improved the chlorophyll content, the net photosynthetic rate (Pn), contents of soluble sugars and soluble protein in the leaves of chrysanthemum, and increased the flower size, fresh weight, vase life, activities of antioxidant enzymes, and decreased the malondialdehyde (MDA) content in cut chrysanthemum flowers.It was concluded that the responses of the foliar humic acid fertilizer on postharvest vase life extension of cut chrysanthemum flowers could be related with the higher chlorophyll content, Pn, contents of soluble sugars and soluble protein in the leaves, the greater flower size, fresh weight, activities of antioxidant enzymes, and the lower MDA content in cut chrysanthemum flowers.

The effects of UV-B radiation intensity on biochemical parameters and active ingredients in flowers of Qi chrysanthemum and Huai chrysanthemum.

The article studied UV-B effects on biochemical parameters and active ingredients in flowers of Qi chrysanthemum and Huai chrysanthemum during the bud stage. The experiment included four UV-B radiation levels (CK, ambient UV-B; T1, T2 and T3 indicated a 5%, 10% and 15% increase in ambient UV-BBE, respectively) to determine the optimal UV-B radiation intensity in regulating active ingredients level in flowers of two chrysanthemum varieties. Flower dry weight of two cultivars was not affected by UV-B radiation under experimental conditions reported here. UV-B treatments significantly increased the rate of superoxide radical production, hydrogen peroxide (H2O2) (except for T1) and malondialdehyde concentration in flowers of Huai chrysanthemum and H2O2 concentration in flowers of Qi chrysanthemum. T2 and T3 treatments induced a significant increase in phenylalanine ammonia lyase enzyme (PAL) activity, anthocyanins, proline, ascorbic acid, chlorogenic acid and flavone content in flowers of two chrysanthemum varieties, and there were no significant differences in PAL activity, ascorbic acid, flavone and chlorogenic acid content between the two treatments. These results indicated that appropriate UV-B radiation intensity did not result in the decrease in flower yield, and could regulate PAL activity and increase active ingredients content in flowers of two chrysanthemum varieties.

Responses of Physiological Traits and Nutritional Ingredients Content in Flowers of Medicinal Chrysanthemum to Selenium Application at Different Growth Stages

The paper mainly studied the effects of selenium (Se) application time on physiological traits and nutritional ingredients in flowers of medicinal chrysanthemum. Flower dry weight and Se concentration in flower were significantly increased by Se application at vigorous growth, bud differentiation and bud stages. Spraying Se at seedling and flower stages evidently increased Se concentration, but did not affect flower dry weight. The rate of superoxide radical production, hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>) and malondialdehyde concentration were significantly decreased by Se application at vigorous growth (except for H<SUB>2</SUB>O<SUB>2</SUB>), bud differentiation and bud stages. At five growth stages, Se application significantly increased glutathione peroxidase activity. At bud differentiation and bud stages, Se application significantly increased penylalanine ammonia lyase enzyme activity, chlorogenic acid, free amino acid and vitamin C content. These results indicated that Se applied at bud differentiation---bud stage was more beneficial for flower dry weight, Se concentration and nutritional ingredients content in flowers.

Phylogenetic analysis of Korean native Chrysanthemum species based on morphological characteristics

In the analysis of genetic relationship among Korean native Chrysanthemum species, the morphological characteristics of 15 taxa of Chrysanthemum species were investigated. Principal component analysis (PCA) and cluster analysis were conducted for the grouping based on the morphological data. Fifteen taxa of Chrysanthemum species were classified into three groups through PCA and cluster analysis based on the general plant growth and flowering characteristics. Groups I and II included non-bushy type and big size flower plants, while Group III included bushy type and small size flower plants. Group I had nine C. zawadskii subspecies: acutilobum, acutilobum var. tenuisectum, acutilobum var. alpinum, lucidum, coreanum, naktongense, yezoense, latilobum, and latilobum var. leiophyllum. Group I was found to be desirable species as garden plants because of the white or pink flowers with a relatively large size (flower head diameter of 43.5–67.6mm), good plant height (19.3–64.6cm), and long flowering period (24–39d). C. lineare was the only species included in Group II with unique cone head shaped seeds and no petiole. Group III included five C. indicum species and related species: C. indicum, C. indicum var. albescens, C. indicum var. acuta, C. boreale, and C. makinoi. Group III had great potentials as edible medicinal resources; e.g., chrysanthemum flower tea, which is abundant in number and has small sized flowers with white or yellow petals. The study provided a clear diagnostic key for the classification showing the species-specific plant form attributable to unique leaves, branch type, plant height, flower size, and flowering habits.

Nursery Crop Growth Response to Municipal Biosolids: Species Salt and Xeric Adaptation a Key Factor?

ABSTRACTGrowth responses of potted ornamental crops to municipal biosolids in the semiarid southwestern USA are not adequately known. In 10- to 11-wk greenhouse pot studies, we evaluated the effects of dried biosolids-amended growing media on four ornamental crop species: Garden chrysanthemum (Dendranthema Xgrandiflorum ‘Megan’), butterfly bush (Buddleia davidii ‘Nanho Blue’), Japanese honeysuckle (Lonicera japonica ‘Purpurea’), and blanket flower (Gaillardia Xgrandiflora ‘Goblin’). The biosolids were composted without bulking agents (100% sewage sludge) and incorporated into growing media at rates ranging from 0 to 593 kg m−3, or 0 to 72% by volume. Biosolids increased substrate pH from 5.8 to 7.2 and electrical conductivity (EC) from 2.6 to 47.3 dS m−1. Any addition of biosolids (≥30 kg m−3) reduced total plant dry matter (DM) of chrysanthemum. Conversely, shoot DM of blanket flower and butterfly bush increased by four- to five-fold at biosolids rates of 59 to 148 kg m−3 (7 to 18% by volume) with corresponding increases in shoot N and P concentrations. Biosolids rates higher than 148 kg m−3 reduced top growth of the latter two species and of Japanese honeysuckle. For all species, growth reductions with excessive biosolids rates likely resulted from osmotic stress and specific NH4 toxicity. However, based on the substantial growth stimulations at moderate biosolids rates, xeric and salt-adapted species, such as blanket flower and butterfly bush, may be ideally suited for expanding the use of highly saline biosolids at semiarid nursery production sites.

Three-dimensional fluorescence characteristics of white chrysanthemum flowers

White chrysanthemum flower is one of the most popular plants found everywhere in China and used as herbs. In the present work, three-dimensional fluorescence technique was used to discriminate species of white chrysanthemum flowers. Parameters affecting extraction efficiency were investigated. Under the optimal conditions, the three-dimensional fluorescence characteristics of three types of white chrysanthemum flowers were obtained. It was found that there were two main fluorescence peaks with remarkable difference in fluorescence intensity, one was corresponding to flavonoids and another was attributed to chlorophyll-like compounds. There were remarkable differences among the contours of the three white chrysanthemum flowers. Further studies showed that the fluorescence intensity ratios of chlorophyll-like compounds to flavonoids had a certain relationship with the species; those for Huai, Hang and Huangshan white chrysanthemum flowers were 6.9–7.4, 18.9–21.4 and 73.6–84.5, respectively. All of the results suggest that three-dimensional fluorescence spectra can be used for the discrimination of white chrysanthemum flowers with the advantages of low cost, ease for operation and intuition.

Administered chrysanthemum flower oil attenuates hyperuricemia: mechanism of action as revealed by DNA microarray analysis.

We applied Chrysanthemum flower oil (CFO) to a hyperuricemia model by feeding rats a hyperuricemia-inducing diet (HID) and investigated its effect on serum uric acid (SUA) levels and its mode of action. CFO is the oily fraction that contains polyphenols derived from chrysanthemum flowers. Oral administration of CFO to HID-fed rats significantly decreased their SUA levels. It also inhibited xanthine oxidase activities in the liver and increased urine uric acid levels. The effects of CFO on the renal gene expressions that accompanied the induction of hyperuricemia were comprehensively confirmed by DNA microarray analysis. The analysis showed up-regulation of those genes for uric acid excretion by CFO administration. These results suggest that CFO suppresses the increase in SUA levels via two mechanisms: suppression of uric acid production by inhibition of xanthine oxidase in the liver and acceleration of its excretion by up-regulation of uric acid transporter genes in the kidney.

Permethrin, a pyrethroid insecticide, impairs insulin‐stimulated glucose uptake in C2C12 myotubes (1142.7)

Pyrethroids are a class of insecticides structurally derived from the naturally occurring insecticides called pyrethrins originating from Chrysanthemum flowers. Based on emerging evidence that exposures to pyrethroid insecticides were linked to altered glucose homeostasis, we investigated the role of permethrin (a pyrethroid insecticide) on glucose uptake using a C2C12 myotube model. C2C12 myoblasts were differentiated into myotubes with 0, 10, and 20 μM permethrin for 8 days. Permethrin treatment significantly reduced insulin stimulated glucose uptake in this model. Further, we found that permethrin affected insulin‐stimulated phosphorylation of Protein Kinase B (AKT) without altering total AKT levels, targeted at both Serine (Ser 473) and Threonine (Thr 308) sites. Permethrin inhibited insulin‐stimulated activation of phosphoinositide‐dependent kinase (pPDK), one upstream regulator of phosphorylation on AKT at Thr 308, without influencing activation of phosphatase and tensin homolog (pPTEN). These data suggest that permethrin impaired insulin responses by influencing AKT signaling by regulating two independent pathways, upstream of PDK/Thr 308 AKT and regulator(s) of Ser 473 AKT.

Transfer of difenoconazole and azoxystrobin residues from chrysanthemum flower tea to its infusion

Investigations of the transfer of pesticide residues from tea to its infusion can be important in the assessment of the possible health benefits of tea consumption. In this work the transfer of difenoconazole and azoxystrobin residues from chrysanthemum tea to its infusion was investigated at different water temperatures, infusion intervals and times. The transfer percentages were in the range of 18.7–51.6% for difenoconazole and of 38.1–71.2% for azoxystrobin, and increased considerably with longer infusion intervals. The results indicated that azoxystrobin with a lower octanol–water partition coefficient of 2.5, showed a higher transfer than that of difenoconazole with a relatively high octanol–water partition coefficient of 4.4. Water temperature had no significant effect on the transfer of the two residues, and no obvious loss of difenoconazole and azoxystrobin occurred during the infusion process. The concentrations in the infusions decreased gradually from 0.67 to 0.30 μg kg−1 for difenoconazole and from 2.3 to 0.46 μg kg−1 for azoxystrobin after five infusions. To assess the potential health risk, the values of estimate expose risk were calculated to be 0.016 for difenoconazole and 0.0022 for azoxystrobin, meaning the daily residue intake of the two analytes from chrysanthemum tea was safe. This research may help assure food safety and identify the potential exposure risks from pesticides in chrysanthemum that may be health concerns.

Effect of Weed Management Practices in Chrysanthemum (Dendranthema grandifloraT.) under Chhattisgarh Plains Agro-climatic Condition

The present experiment was conducted at the Department of Horticulture, Indira Gandhi Krishi Vishwavidyalaya, Raipur (Chhattisgarh) during winter season to evaluate the effect of weed management practices on the growth and flowering of chrysanthemum. The experiment consisted of eleven treatments comprising of hand weeding, mulching, herbicides and unweeded check replicated three times in randomized block design. Maximum plant height, plant spread and number of branches plant−1 were recorded on application of pendimethalin (extra) @ 0.64 kg ha−1+one hand weeding at 40 DAT+pendimethalin (extra) @ 0.64 kg ha−1at 45 DAT followed by pendimethalin @ 1.0 kg ha−1+one hand weeding at 40 DAT which had at par effect. Highest average flower weight, number of flowers plant−1, flower diameter and earliest days to first bud appearance was obtained with pendimethalin (extra) @ 0.64 kg ha−1+one hand weeding at 40 DAT+pendimethalin(extra) @ 0.64 kg ha−1at 45 DAT which was having same effect as with pendimethalin @ 1.0 kg ha−1+one hand weeding at 40 DAT. The minimum dry matter and nitrogen uptake was noted under pendimethalin (extra) @ 0.64 kg ha−1+one hand weeding at 40 DAT+pendimethalin (extra) @ 0.64 kg ha−1 at 45 DAT. Application of pendimethalin (extra) @ 0.64 kg ha−1+one hand weeding at 40 DAT+pendimethalin (extra) @ 0.64 kg ha−1 at 45 DAT was found superior for parameters under observations, but it was found to have at par effect with pendimethalin @ 1.0 kg ha−1+one hand weeding at 40 DAT.

Growth and flowering responses of cut chrysanthemum grown under restricted root volume to irrigation frequency.

Influences of irrigation frequency on the growth and flowering of chrysanthemum grown under restricted root volume were tested. Chrysanthemum cuttings (Chrysanthemum morifolium “Reagan White”) were grown in seedling tray which contained coconut peat in volumes of 73 and 140 cm3. Plants were irrigated with drip irrigation at irrigation frequencies of 4 (266 mL), 6 (400 mL), and 8 (533 mL) times/day to observe their growth and flowering performances. There was interaction between irrigation frequency and substrate volume on plant height of chrysanthemum. Plants grown in 140 cm3 substrates and irrigated 6 times/day produced the tallest plant of 109.25 cm. Plants irrigated 6 and 8 times/day had significantly higher level of phosphorus content in their leaves than those plants irrigated 4 times/day. The total leaf area, number of internodes, leaf length, and leaf width of chrysanthemums grown in 140 cm3 substrate were significantly higher than those grown in 73 cm3 substrate. The numbers of flowers were affected by both irrigation frequencies and substrate volumes. Chrysanthemums irrigated 8 times/day had an average of 19.56 flowers while those irrigated 4 times/day had an average of 16.63 flowers. Increasing irrigation frequency can improve the growth and flowering of chrysanthemums in small substrate volumes.

Fusarium Wilt of Chrysanthemum – Problems and Prospects

Chrysanthemum flower production is adversely affected by many bacterial, fungal and viral diseases. Wilt caused by Fusarium oxysporum f. sp. chrysanthemi is one of the most serious diseases and causes severe yield losses. The pathogen enters the plant, multiply and blocks the vascular system with or without involvement of toxins and enzymes. Multiplication medium, pH and temperature plays significant role on the growth and sporulation of Fusarium oxysporum. Moderate temperatures, high humidity, availability of plant nutrients in soil encourage rapid disease development. High inoculum density causes greater disease incidence, hasty disease advancement and low flower yield. Degree of symptom development is related with the cultivar resistance and susceptibility. Plant extracts, polar and non-polar fractions, their pure compounds, and essential oils have potential antimicrobial activity against Fusarium oxysporum. The active phyto-constituents responsible for antifungal properties are low molecular weight phenols, tannins and lignin. Trichoderma and other phyto-pathogenic fungi are known to diminish wilt disease caused by Fusarium oxysporum f. sp. chrysanthemi. Myco-parasitism, antibiosis, nutrient competition and starvation, siderophore production and induction of systemic resistance are the major mechanism employed by Trichoderma for controlling pathogens. The present paper is intended to discuss the aspects of epidemiology, pathogenesis and biological control measures of Fusarium oxysporum with emphasis on Chrysanthemum wilt.

A Rare Poisoning with Pyrethroid by an Uncommon Route of Self Injection

Pyrethroids are structurally modified chemicals of naturally available extract of flower Chrysanthemum cinerariifolium. They are mainly used as insecticide. They are not known to be highly toxic to humans. But some reports of heavy accidental exposure by inhalation or dermal contact have been reported. But this is the first case of attempt of self-harm with pyrethroid that too by self-injection. Here we present a case and review all the toxicity of pyrethroids reported.

Responses of supplemental blue light on flowering and stem extension growth of cut chrysanthemum

To determine the effects of blue (B) spectrum supplemental lighting on flower bud formation and stem elongation growth of cut chrysanthemum, plants of ‘Zembla’ cultivar were grown for 42 days under 4 different light treatments. Treatments comprised: RB (11h of mixed red and blue [RB] light), RB+B (11h of mixed RB light and then 4h of supplemental B light), LRB+B (15h of mixed RB light and then 4h of supplemental B light) and RB+LB (11h of mixed RB light and then 13h of B light) by using light-emitting diodes. Diurnal patterns in the net assimilation rate were observed, depending on light-quality combinations. Under mixed RB light, the net assimilation rate increased rapidly, then slightly decreased under B light, and finally dropped to negative values during darkness. Final stem length was the highest in plants grown under RB+LB, followed by LRB+B, RB+B and then RB treatment. The stem lengths under RB+B, LRB+B and RB+LB were 1.3, 1.5 and 1.7 times longer than that of RB treatment, respectively. However, fully developed flower buds were formed under RB and RB+B treatments only. The extended final stem length of RB+B plants was determined by internode extension. Overall, our results indicate that supplemental B light, at least in part, may promote stem and internode elongation growth without any inhibitory effect on flower bud formation. The results of this study present a useful practical technique for optimizing cut chrysanthemum production in greenhouse horticulture.

Flower Colour Modification of Chrysanthemum by Suppression of F3'H and Overexpression of the Exogenous Senecio cruentus F3'5'H Gene

Chrysanthemum (Chrysanthemum × morifolium) is one of the most important ornamental plants in the world. They are typically used as cut flowers or potted plants. Chrysanthemum can exhibit red, purple, pink, yellow and white flowers, but lack bright red and blue flowers. In this study, we identified two chrysanthemum cultivars, C × morifolium ‘LPi’ and C × morifolium ‘LPu’, that only accumulate flavonoids in their ligulate flowers. Next, we isolated seven anthocyanin biosynthesis genes, namely CmCHS, CmF3H, CmF3’H, CmDFR, CmANS, CmCHI and Cm3GT in these cultivars. RT-PCR and qRT-PCR analyses showed that CmF3′H was the most important enzyme required for cyanidin biosynthsis. To rebuild the delphinidin pathway, we downregulated CmF3’H using RNAi and overexpressed the Senecio cruentus F3′5′H (PCFH) gene in chrysanthemum. The resultant chrysanthemum demonstrated a significantly increased content of cyanidin and brighter red flower petals but did not accumulate delphinidin. These results indicated that CmF3′H in chrysanthemum is important for anthocyanin accumulation, and Senecio cruentus F3′5′H only exhibited F3′H activity in chrysanthemum but did not rebuild the delphinidin pathway to form blue flower chrysanthemum.

Nested PCR Detection of Chrysanthemum stunt viroid (CSVd) from Chrysanthemum Cultivar Seedlings

Chrysanthemum stunt viroid (CSVd) is a serious pathogen affecting chrysanthemum that has caused significant economic losses to Chrysanthemum flower production worldwide. Control of CSVd disease is difficult due to its contagious nature and long latent period in the field. As chrysanthemum is most often produced by implanting seedlings, it is necessary to diagnose CSVd infection before cultivation. In this study, we screened CSVd infection in seedlings from 30 varieties including 5 domestic, 6 Japanese, and 19 European varieties. Molecular diagnosis of the combination of RT-PCR and nested PCR showed that CSVd was not detected by the first RT-PCR but detected by the second nested PCR analysis in 10 varieties, including 1 domestic, 2 Japanese, and 7 European varieties. Further comparison of 10 identified CSVd nucleotide sequences showed that those are highly conserved (99-100%) and the most similar to an isolate (AB006737) identified in Hokkaido, Japan. Our study suggests that the combination of RT-PCR and nested PCR analysis is successful for the CSVd diagnosis of seedlings and the molecular diagnosis is necessary to prevent the introduction and propagation of viroid disease into the fields.

Violet/Blue Chrysanthemums—Metabolic Engineering of the Anthocyanin Biosynthetic Pathway Results in Novel Petal Colors

Chrysanthemums (Chrysanthemum×morifolium Ramat.) are an important cut-flower and potted plant crop in the horticultural industry world wide. Chrysanthemums express the flavonoid 3'-hydroxylase (F3'H) gene and thus accumulate anthocyanins derived from cyanidin in their inflorescences which appear pink/red. Delphinidin-based anthocyanins are lacking due to the deficiency of a flavonoid 3', 5'-hydroxylase (F3'5'H), and so violet/blue chrysanthemum flower colors are not found. In this study, together with optimization of transgene expression and selection of the host cultivars and gene source, F3'5'H genes have been successfully utilized to produce transgenic bluish chrysanthemums that accumulate delphinidin-based anthocyanins. HPLC analysis and feeding experiments with a delphinidin precursor identified 16 cultivars of chrysanthemums out of 75 that were predicted to turn bluish upon delphinidin accumulation. A selection of eight cultivars were successfully transformed with F3'5'H genes under the control of different promoters. A pansy F3'5'H gene under the control of a chalcone synthase promoter fragment from rose resulted in the effective diversion of the anthocyanin pathway to produce delphinidin in transgenic chrysanthemum flower petals. The resultant petal color was bluish, with 40% of total anthocyanidins attributed to delphinidin. Increased delphinidin levels (up to 80%) were further achieved by hairpin RNA interference-mediated silencing of the endogenous F3'H gene. The resulting petal colors were novel bluish hues, not possible by hybridization breeding. This is the first report of the production of anthocyanins derived from delphinidin in chrysanthemum petals leading to novel flower color.

Development of a fast analytical method for the individual determination of pyrethrins residues in fruits and vegetables by liquid chromatography–tandem mass spectrometry

Pyrethrins are natural insecticides derived from chrysanthemum flowers containing a mixture of six components: pyrethrin I, cinerin I, jasmolin I, pyrethrin II, cinerin II, and jasmolin II. In this work, a rapid and sensitive LC–(ESI)-MS/MS method has been developed for the individual quantification and confirmation of pyrethrin residues in fruit and vegetable samples by monitoring two specific transitions for each pyrethrin component under Selected Reaction Monitoring (SRM) mode. Samples were extracted with acetone/water or acetone, depending on the sample type, and raw extracts were directly injected in the LC–MS/MS system. Method validation was carried out evaluating linearity, accuracy, precision, specificity, limit of quantification (LOQ) and limit of detection (LOD) in eight types of fruit and vegetable samples at 0.05mg/kg and 0.5mg/kg (referred to the sum of all pyrethrins). The method based on acetone/water (70:30) extraction led to satisfactory recoveries (70–110%) and good precision (below 14%) for all pyrethrin components in lettuce, pepper, strawberry and potato. The method based on acetone extraction allowed satisfactory recoveries for lettuce, cucumber, tomato and rice samples with recoveries between 71 and 107% and RSDs below 15%. For pistachio samples, satisfactory results were obtained only for some analytes and extracts were also injected using APCI interface, but the lower sensitivity achieved allowed only the validation at 0.5mg/kg. The analytical methodology developed was applied to the analysis of fruit and vegetable samples.

적색광을 이용한 국화의 개화조절

BACKGROUND: The incandescent bulb and compact fluorescent lamp are widely using as a light sources for daylength extension of chrysanthemum. But, these light sources consume a lot of electricity and have short longevity. A light-emitting diode (LED) is a semi conductor light source. LEDs have many advantages over incandescent light sources including lower energy consumption, longer lifetime. In this study, we investigated the intensity of red light to control flowering of chrysanthemum (Dendranthema grandiflorum cv. Shinma) by using LEDs. METHODS AND RESULTS: The red (660 nm) and far-red (730 nm) light were irradiated subsequently to investigate photo-reversible flowering responses of chrysanthemum. The flowering of chrysanthemum was inhibited by night interruption with red light but subsequently irradiated far-red light induced the flowering of chrysanthemum. This photoreversibility, reversion of the inductive effect of a brief red light pulse by a subsequent far-red light pulse, is a property of photo responses regulated by the plant photoreceptor phytochrome B.

Daminozide Alters Anthocyanin Metabolism in Ray Florets of Bronze Chrysanthemum (Chrysanthemum morifolium Ramat.)

Daminozide is a well-known chemical inhibitor of the gibberellic acid biosynthesis pathway regulating the vegetative growth of potted chrysanthemums (Chrysanthemum morifolium Ramat.). However, the precise mechanism underlying daminozide-related floral color loss is unknown. To investigate the latter, in two separate greenhouse experiments, bronze flowering chrysanthemum cultivars ‘Baton Rouge’ and ‘Pelee’ were treated weekly with consecutive (0 or 5,000 mg l−1) foliar daminozide spray applications at early, intermediate, and late stages during the short-day photoperiod. The ray florets of both cultivars were sampled, and the effect of daminozide application on anthocyanins and their biosynthetic precursors were determined by HPLC. Daminozide applied to ‘Baton Rouge’ plants at early developmental stages was correlated with partial loss of red color, and HPLC analysis determined that this was associated with a 75 % reduction in ray floret anthocyanins. Conversely, a near complete loss of red coloration in daminozide-sprayed ‘Pelee’ relative to control plants was associated with as much as a 98 % decline in anthocyanins, irrespective of the time of application. HPLC analysis determined that daminozide application was associated with a 22–50 % increase in the flavones apigenin 7-O-rutinoside, acacetin 7-O-rutinoside, diosmetin 7-O-rutinoside, and eupatorin, and a 68 % increase in the flavonol quercetin 3-O-glucoside, in ray florets of ‘Pelee’ relative to control plants. There was no relative change in ‘Baton Rouge’ flavone and flavonol levels. The accumulation of bronze C. morifolium flavones and flavonols following foliar daminozide application suggests that red color loss is associated with inhibition of anthocyanidin synthase of ‘Pelee’ ray florets.