Search Results (13)

The presence of bioactive compounds in plants with red flowers constitutes a valuable natural resource for the food, pharmaceutical, and medical industries. This paper aims to highlight these characteristics to facilitate the selection of extracts according to market needs. The analyzed parameters can provide valuable insights into the compositional variability of the five red flower plants, as new sources of bioactive compounds and natural antioxidants of plant origin. Five plants with red flowers (Magnolia liliiflora, Chrysanthemum morifolium, Hibiscus sabdariffa, Petunia grandiflora, Rosa hybrida L.) were selected and investigated regarding their polyphenol concentration, total anthocyanins, antioxidant activity, phenolic compounds, and antimicrobial activity. Total polyphenols were found in concentrations ranging from 75.17 ± 0.16 mgGAE/g (C. morifolium) to 107.49 ± 0.19 mgGAE/g (R. hybrida L.), and total anthocyanins between 14.99 ± 0.13 mg Cy-3-Glu/g and 21.66 ± 0.18 mg Cy-3-Glu/g. The antioxidant activity DPPH/IC50 mg/mL for the extract from R. hybrida L. flowers reached a value of 29.35 ± 0.17 mg/g, with ABTS and FRAP achieving maximum values of 49.89 ± 0.24 mmol TE/g and 48.68 ± 0.23 mmol TE/g, respectively. The antibacterial activity was particularly evident against strains commonly encountered in human pathology, Escherichia coli and Staphylococcus aureus, with reduced or no impact on strains of Pseudomonas fluorescens and Proteus mirabilis. The results demonstrated that the extracts from the selected, red-flowered plants contain valuable biologically active compounds in generous quantities, thus recommending their use in the food, pharmaceutical, and medical sectors. Full article

Rosa hybrida is one the most commonly cultivated ornamental plant of economic importance and faces major challenges under heat stress. Melatonin has been widely shown to regulate plant stress response; however, the exact mechanism involved in heat stress in R. hybrida has yet to be determined. Here, we observed that R. hybrida in vitro plantlets supplemented with melatonin in the culture medium exhibited higher chlorophyll content, relative ion leakage, and fresh weight after 12 d of high-temperature treatment; the optimal concentration was established at 5 mg/L. Using molecular and biochemical techniques, we explored the roles of a melatonin synthase gene RhCOMT1, which expression was influenced by heat stress and melatonin. RhCOMT1 was located in the nuclear-cytoplasmic under ambient conditions, while heat stress translocated the distribution of RhCOMT1 to chloroplasts. Overexpression of RhCOMT1 in rose petal enhanced thermotolerance, and silencing of RhCOMT1 reduced thermotolerance via affect H₂O₂ content and relative ion leakage. These findings collectively emphasize the pivotal role of melatonin in enhancing thermotolerance to R. hybrida by alleviation of oxidative stress, through modulation of RhCOMT1 expression and location. Full article

Roses are one of the most important flowers applied to landscape, cut flowers, fragrance and food industries widely. As an effective method for plant reproduction, the regeneration via somatic embryos is the most promising method for breed improvement and genetic transformation of woody plants. However, lower somatic embryogenesis (SE) induction rates and genotypic constraints impede progress in genetic transformation in rose. This study describes a plant regeneration system for the famous red cut flower cultivar Rosa hybrida ‘Carola’. The stems without petioles cultured on Murashige and Skoog (MS) medium supplemented with 1.0 mg·L⁻¹ 6-benzylaminopurine (6-BA), 0.05 mg·L⁻¹ a-naphthalene acetic acid (NAA) and 30 g·L⁻¹ sucrose showed the maximum proliferation coefficient of shoots with 3.41 for the micropropagation system. We evaluated the effects of different plant growth regulators (PGRs) on the induction, proliferation and conversion of somatic embryos. The induction rate of calli reached 100% on MS medium supplemented with 2.0 g·L⁻¹ NAA and 30 g·L⁻¹ glucose. The highest induction rate of somatic embryos achieved a frequency of 13.33% on MS medium supplemented with 2.0 mg·L⁻¹ zeatin (ZT), 0.1 mg·L⁻¹ NAA and 30 g·L⁻¹ glucose. The most suitable carbohydrate with 60 g·L⁻¹ glucose resulted in a proliferation rate of somatic embryos (4.02) on MS medium containing 1.5 mg·L⁻¹ ZT, 0.2 mg·L⁻¹ NAA and 0.1 mg·L⁻¹ gibberellic acid (GA₃). The highest somatic embryos germination rate (43.33%) was obtained from the MS medium supplemented with 1.0 mg·L⁻¹ 6-BA, 0.01 mg·L⁻¹ IBA and 30 g·L⁻¹ glucose. Finally, the germinated somatic embryos successfully rooted on 1/2 MS medium containing 1.0 mg·L⁻¹ NAA, 30 g·L⁻¹ sucrose, and the vigorous plantlets were obtained after hardening-off culture. This study provided a stable and efficient protocol for plant regeneration via somatic embryos in R. hybrida ‘Carola’, which will be beneficial to the further theoretical study and genetic improvement in roses. Full article

Roses are increasingly being grown in soilless systems to increase productivity and reduce the challenges associated with soil-based cultivation. This study investigates the effects of using cocopeat and volcanic tuff substrates, the particle size of tuff, and substrate depth on the growth and flower quality of roses (Rosa hybrida L. cv. top secret) grown under greenhouse conditions. The treatments were cocopeat, tuff, cocopeat–tuff mixture, and tuff of particle size of 2 to 4 mm, 0 to 4 mm, and 0 to 8 mm at depths of 20 cm and 40 cm. The results showed that cocopeat had the highest water-holding capacity and photosynthetic rate. Tuff substrates had higher chlorophyll content throughout the growing season. Although flower numbers per plant in cocopeat and tuff from 0 to 8 mm at a depth of 20 cm were statistically similar, tuff from 0 to 8 mm had longer flowering stems and larger post-harvest flower diameters than cocopeat. An increase in the tuff depth from 20 to 40 cm decreased the flower number and main stem diameter. In conclusion, while cocopeat promotes rapid initial growth, volcanic tuff substrates, particularly tuff from 0 to 8 mm at a depth of 20 cm, provide long-term benefits for flower quality and plant health. Full article

The widespread use of artificial light at night (ALAN) due to urbanization and infrastructure development has raised concerns about its potential impacts on plant physiology. To explore the effects of ALAN with different light intensities on the photosynthesis and respiration of two urban vascular plants, Euonymus japonicus Thunb and Rosa hybrida E.H.L.Krause, under continuous and non-continuous-light conditions, respectively, a field experiment was conducted. Our findings indicate that continuous ALAN significantly inhibited the photosynthesis and respiration of the two plants, disrupting the carbon-balance pattern of their leaves during the day, but this effect is influenced by the intensity of ALAN and plant species. Euonymus japonicus Thunb is more susceptible to continuous ALAN than Rosa hybrida E.H.L.Kraus. Non-continuous ALAN did not significantly affect the photosynthesis and respiration of two species during the day. Furthermore, we observed that high light intensity at night could also impact the value of the net photosynthetic rate (Pn) of Euonymus japonicus Thunb during the night. Turning off light sources at night, reducing the light intensity, and cultivating ALAN-tolerant plants are effective measures to reduce the negative effects of ALAN on plants and maintain plants’ normal carbon-balance mode. Future studies should explore the effects of different types of artificial-light sources combined with other environmental conditions on the photosynthesis and respiration of plants at the canopy scale. Full article

Modern roses (Rosa × hybrida) are among the most important and economically profitable horticultural plants. Besides their beauty and remarkable fragrance, they are also rich sources of biologically active compounds with potential health benefits. The aim of this study was to valorize the prospective of six new genotypes of edible roses to be utilized as functional foods. Rose flowers were subjected to detailed characterization of morphological traits, fragrance analysis, GC-MS analysis of aroma carriers, determination of phenolic profile and vitamin C content, and evaluation of biological activities. The results showed that all the investigated cultivars have a favorable aroma for human consumption (pear-like, strawberry-like or fruity), high contents of phenolics and vitamin C, strong antioxidant content and moderate neuroprotective activity. They are characterized by large amounts of quercetin 3-O-glycosydes and quinic acid. The genotype ‘Marija Frayla’ stands out from others due to facilitated flower morphology, the highest level of total phenolics (217 mg of galic acid equivalents/g of dry extract) and the strongest antioxidant activity (in the DPPH assay, IC₅₀ = 9.24 µg/mL; and antioxidant potential in the FRAP assay was 220 mg ascorbic acid equivalents/g of dry extract), thus represents the most valuable amendment to the development of novel functional food products. The ‘Eveline Wild’ genotype has the highest neuroprotective activity (68.5 ng of eserine equivalents/g of dry extract), thus might be applied in the prevention of dementia. The ‘Pear’ cultivar with the lowest phenolics content and biological activity has a mild, fruity aroma, thus can be used in everyday eating. Full article

Cut roses are highly valuable ornamentals and their profitability depends on the flower postharvest performance. Bent neck symptoms in roses make them unmarketable and are typically related to physiological disorders, bacteria accumulation in the vase solution, and Botrytis cinerea infection. Unusual bent neck symptoms were observed in 4.7% of ‘Orange Crush’ roses from two commercial shipments, resulting in complete flower collapse. This research was aimed to determine the causal agent of the bent neck symptoms. Following incubation in a humid chamber, symptomatic roses evolved in water-soaked lesions with the presence of white mycelium and sclerotia development. Fungal isolations and molecular characterization were performed and Sclerotinia sclerotiorum was identified as the causal agent of rose bent neck. Therefore, when bent neck symptoms are observed, S. sclerotiorum incidence should be considered to avoid possible outbreaks. Full article

The quality of the host plant affects the life history parameters of tetranychid mites. The biology and fertility life tables of Tetranychus merganser on five host plants (Carica papaya, Phaseolus vulgaris, Capsicum annuum var. glabriusculum, Helietta parvifolia, and Rosa hybrida) were assessed under laboratory conditions at 28 ± 1 °C and 70–80% relative humidity (RH) with a photoperiod of 12:12 h (L:D). The development period of immature females differed among the tested host plants and ranged from 9.32 days on P. vulgaris to 11.34 days on H. parvifolia. For immature males, it ranged from 9.25 days on P. vulgaris to 11.50 days on H. parvifolia. The female survival rate varied from 53.97% on H. parvifolia to 94.74% on P. vulgaris. The highest total fecundity rate was recorded on P. vulgaris (125.40 eggs/female) and the lowest on H. parvifolia (43.92 eggs/female). The intrinsic rate of increase (rm) varied from 0.271 (H. parvifolia) to 0.391 (P. vulgaris). The net reproductive rate (R_O) was higher on P. vulgaris than on the other host plants. The longest mean generation time (GT) was calculated on C. annuum var. glabriusculum and the shortest on Rosa hybrida. The demographic parameters suggest the unsuitability of H. parvifolia as the host for the development of red spider mites, and the best performance of T. merganser was on P. vulgaris. Full article

Garden rose, Rosa hybrida, is primarily used for decoration and has a wide range of growing area, contrary to R. damascena that has a limited area of distribution (Turkey and Bulgaria), yet it is extensively used for commercial production of valuable and expensive rose oil. Since the content of essential oil in rose petals is low (0.03–0.04%), its production is quite limited; however, during this process, a significant amount of rose hydrosol is obtained as a secondary product. The aim of this research was to determine the chemical composition of garden rose hydrosols and to evaluate their biological properties. Obtained results show that R. hybrida hydrosol containing phenylethyl alcohol, nerol, linalool, and geraniol may be used as an alternative for R. damascena hydrosol. However, the total phenolic content was quite low (4.96 µg GAE/mL), which is related to a low level of observed antioxidant activity based on different antioxidant activity assays. Furthermore, R. hybrida hydrosol did not exhibit antimicrobial activity against several gram-positive and gram-negative bacteria, as well as yeast and fungi. Anti-inflammatory activity was also low, while no antihyperglycemic activity was detected. With these results in mind, no potential is evident for the therapeutic application of rose hydrosol beyond that found in complimentary medicine such as aromatherapy. Full article

The study of the regulatory mechanism of exogenous plant growth regulators (PGRs) on the relevant physiological indicators is essential to maintain the normal growth of Rosa hybrida under high-temperature conditions. The photosynthetic and physiological characteristics of the ornamental cut rose Rosa hybrida ‘Carolla’ under high temperature were studied by spraying leaves with various concentrations of exogenous salicylic acid (SA; 0.5, 1.0, 1.5, or 2.0 mmol·L⁻¹), 6-benzylaminopurine (6-BA; 10, 20, 30, or 50 μmol·L⁻¹), abscisic acid (ABA; 10, 20, 30, or 50 mg·L⁻¹), or distilled water (control). The results indicated that a foliar spray of either SA, 6-BA, or ABA could mitigate the impact of high temperatures. Compared to the control, the application of SA, 6-BA, or ABA increased the net CO₂ assimilation rate (A_n), transpiration rate (E), stomatal conductance (G_s), and water use efficiency (WUE) of ‘Carolla’, while decreasing the leaf relative electrical conductivity (REC) and malondialdehyde (MDA) content. The applications of SA, 6-BA, or ABA increased the activities of the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) and altered the proline (Pro), soluble protein, and soluble sugar contents. The results showed that foliar sprays of SA, 6-BA, or ABA could enhance the heat tolerance of ‘Carolla’ by promoting photosynthesis, cell membrane structural stability, antioxidant enzyme activity, and osmoregulation in plants under high-temperature stress. The experiment showed that 1.5 mmol·L⁻¹ SA, 20 μmol·L⁻¹ 6-BA, or 75 μmol·L⁻¹ ABA could alleviate the damage caused by high temperatures, with 20 μmol·L⁻¹ 6-BA having the best effect. Full article

Flower senescence varies among cut roses (Rosa hybrida L.), and it is known that the postharvest life of ethylene-sensitive flowers is strongly related to the transcriptional accumulation of ethylene biosynthesis genes, whereas that of ethylene-insensitive flowers is shortened by water stress. These different responses of flowers to hormone and water stresses limit the action of preservatives in inhibiting the postharvest deterioration of cut rose flowers. This study was conducted to investigate the effects of the combined application of antibacterial agents and ethylene biosynthesis and binding inhibitors on the postharvest life and quality of the cut rose cultivars ‘Matador’ (ethylene-sensitive) and ‘Dolcetto’ (ethylene-insensitive). Cut flowers were treated with nano silver (NS), a combination of NS and α-aminoisobutyric acid (NS+A), or a combination of NS+A and 1-methylcyclopropene (NS+AM), and they were subsequently exposed to ethylene for 24 h. Treatment effectiveness was compared with that of control (CON) flowers, which were kept in distilled water and exposed only to ethylene. The results showed that all treatments significantly improved the postharvest quality and vase life of both rose cultivars. However, NS+AM most markedly delayed senescence and prolonged the vase life of cut flowers by 217% in ‘Matador’ and 168.4% in ‘Dolcetto’, compared with those of CON flowers. NS+AM also effectively increased the flower diameter and maintenance time of positive water balance and initial fresh weight by enhancing solution absorption as well as suppressing bacterial growth at the cut stem ends of the cut roses. Furthermore, NS+AM greatly suppressed the ethylene-inducible increase of ethylene biosynthesis genes and the reduction of ethylene receptor genes in petals, which resulted in a reduced flower response to exogenous ethylene in both rose cultivars. These findings show that NS+AM effectively delays flower senescence in both ethylene sensitive and insensitive cultivars by synergistically preventing ethylene response and water stress in cut flowers. Full article

In this study, we compare two rapid cryopreservation (−196 °C) procedures, droplet-vitrification and encapsulation-dehydration for rose (Rosa × hybrida L., cultivars ‘Ioana’, ‘Mariana’, ‘Vulcan’). Significant factors for cryopreservation, such as sucrose concentration during osmoprotection, treatment duration with plant vitrification solution 2 (PVS2) in droplet-vitrification, duration of air desiccation and moisture content of alginate beads in encapsulation-dehydration, were investigated. In addition, the morphogenetic response to in vitro culture and to liquid nitrogen storage and the content in photosynthetic pigments have been assessed. The in vitro cultures were initiated from plant material originating from field collection. The highest regeneration frequencies were obtained for cv. ‘Vulcan’ in both of the cryopreservation procedures tested, 72% in droplet-vitrification and 65% following encapsulation-dehydration. The morphogenetic response (multiplication index and height of shoots) to liquid nitrogen storage was direct multiple shoot formation per initial shoot tip for all genotypes. The content in chlorophyll a and b was statistically comparable in plant material resulting from cryopreserved and non-cryopreserved shoot tips in all cultivars. The findings expand the information on Rosa‘s response to in vitro culture conditions and cryopreservation, providing protocols with a high regeneration capacity for the storage of genotypes with high ornamental value. Full article

Non-destructive, accurate, user-friendly and low-cost approaches to determining crop leaf area (LA) are a key tool in many agronomic and physiological studies, as well as in current agricultural management. Although there are models that estimate cut rose LA in the literature, they are generally designed for a specific stage of the crop cycle, usually harvest. This study aimed to estimate the LA of cut “Red Naomi” rose stems in several phenological phases using morphological descriptors and allometric measurements derived from image processing. A statistical model was developed based on the “multiple stepwise regression” technique and considered the stem height, the number of stem leaves, and the stage of the flower bud. The model, based on 26 stems (232 leaves) collected at different developmental stages, explained 95% of the LA variance (R² = 0.95, n = 26, p < 0.0001). The mean relative difference between the observed and the estimated LA was 8.2%. The methodology had a high accuracy and precision in the estimation of LA during crop development. It can save time, effort, and resources in determining cut rose stem LA, enhancing its application in research and production contexts. Full article