Coreopsis Grandiflora Research Articles

Efficacy and Optimal Timing of Warm-white or Red + Far-red LED Lamps in Regulation of Flowering in Long-day Ornamentals

When natural days are short, photoperiodic lighting at the end or beginning of the day (day extension) or in the middle of the night (night break) promotes flowering of long-day plants. The objective of this study was to compare broad-spectrum warm-white light-emitting diodes (LEDs) and red (R) + far-red (FR) LEDs at flowering regulation when delivered at different timings in the night period. We performed a greenhouse experiment on four long-day ornamentals [coreopsis (Coreopsis grandiflora) ‘Early Sunrise’, snapdragon (Antirrhinum majus) ‘Liberty Classic Yellow’, petunia (Petunia ×hybrida) ‘Easy Wave Burgundy Star’, and petunia ‘Wave Purple Improved’]. We grew plants under a truncated 8-hour photoperiod with or without low-intensity (∼2 μmol·m−2·s−1) nighttime lighting from warm-white or R+FR LEDs. For each light quality, we delivered four timings: 1) 8 hours after dusk; 2) 8 hours before dawn; 3) 4 hours after dusk + 4 hours before dawn; and 4) 4-hour night break. The effectiveness of floral promotion was determined by time from the treatment onset to the first open flower. Coreopsis flowered similarly under all lighting treatments, irrespective of light quality and timing, but did not flower under the short-day treatment by the end of the experiment. At flowering, coreopsis was 18% to 19% shorter under white than R+FR LEDs. In contrast, snapdragon flowered 9 to 20 days later under white than R+FR LEDs, when delivered for 8 hours at night, but flowered similarly under these two lamp types as a 4-hour night break. Compared with the short-day treatment, white and R+FR LEDs promoted flowering of both petunia cultivars, although flowering generally occurred later under white than R+FR LEDs. Snapdragon and petunia ‘Easy Wave Burgundy Star’ developed 30% to 122% more lateral branches under white than R+FR LEDs, when delivered for 8 hours at night. The effectiveness of warm-white LEDs was generally unaffected by timing, although it was most promotive of flowering in snapdragon when delivered for 8 hours before dawn. For R+FR LEDs, 8-hour day-extension lighting was generally more effective than 4-hour night-break lighting, irrespective of timing. We conclude when delivered for 8 hours at night, warm-white LEDs are generally less effective than R+FR LEDs at promoting flowering of long-day ornamentals but similarly effective as 4-hour night-break lighting. The effectiveness of day-extension lighting is generally independent of timing, although for R+FR LEDs, 8 hours after-dusk and/or before-dawn lighting was generally more effective than 4-hour night-break lighting.

Karyomorphology of Seven Different Angiospermic Plants

The focus of this study is on the karyomorphological examination of seven angiospermic plants: Centaurea cyanus L. belonging to the Cynareae tribe; Coreopsis grandiflora Nutt. ex Chapm. and Eclipta prostrata (Linn.) Linn. from the Heliantheae tribe; Eupatorium adenophorum Spreng from the Eupatorie tribe; Gnaphalium affine D. Don. from the Inuleae tribe; Rhynchospermum verticillatum Reinw. from the Astereae tribe; and Tridax procumbens L within the Asteraceae family. Cytological analysis was used to assess the chromosome count and karyomorphology of all seven plants studied in central Nepal. The somatic chromosomal number found in this inquiry was 2n=24 for Centaurea cyanus, which has the karyotype formula M12+ m6+sm2+ st4. Similarly, 2n=26 was found for Coreopsis grandiflora, which has the karyotype formula M14+sm12 and 2n=22 for Eclipta prostrata which has the karyotype formula M14+sm6+st2. The karyotype formula for Eupatorium adenophorum is M4+m12+sm26+st8 and 2n=50, while for Gnaphalium affine, it is M10+sm4, with a 2n=14 value. The karyotype formula for Rhynchospermum verticillatum is M4+ m8+ sm6 with 2n = 18. For Tridax procumbens L, 2n = 26 whose karyotype formula is M18+m4+sm2+ st2.The examined taxa's total length varied from 0.3 µm to 2.6 µm. Int. J. Appl. Sci. Biotechnol. Vol 12(1): 8-18.

Gamma-Aminobutyric Acid Enhances Cadmium Phytoextraction by Coreopsis grandiflora by Remodeling the Rhizospheric Environment.

Gamma-aminobutyric acid (GABA) significantly affects plant responses to heavy metals in hydroponics or culture media, but its corresponding effects in plant-soil systems remain unknown. In this study, different GABA dosages (0-8 g kg-1) were added to the rhizosphere of Coreopsis grandiflora grown in Cd-contaminated soils. Cd accumulation in the shoots of C. grandiflora was enhanced by 38.9-159.5% by GABA in a dose-dependent approach because of accelerated Cd absorption and transport. The increase in exchangeable Cd transformed from Fe-Mn oxide and carbonate-bound Cd, which may be mainly driven by decreased soil pH rather than GABA itself, could be a determining factor responsible for this phenomenon. The N, P, and K availability was affected by multiple factors under GABA treatment, which may regulate Cd accommodation and accumulation in C. grandiflora. The rhizospheric environment dynamics remodeled the bacterial community composition, resulting in a decline in overall bacterial diversity and richness. However, several important plant growth-promoting rhizobacteria, especially Pseudomonas and Sphingomonas, were recruited under GABA treatment to assist Cd phytoextraction in C. grandiflora. This study reveals that GABA as a soil amendment remodels the rhizospheric environment (e.g., soil pH and rhizobacteria) to enhance Cd phytoextraction in plant-soil systems.

Contribution of Surrounding Flowering Plants to Reduce Abundance of Aphis nerii (Hemiptera: Aphididae) on Oleanders (Nerium oleander L.)

Oleander is very frequently planted as an ornamental shrub in urban areas of the Mediterranean. Its most common pest is the aphid Aphis nerii, and heavy infestations produce aesthetic damage and disturbances to the citizens, and they are frequently sprayed with insecticides in order to reduce the population density. One alternative method is conservation biological control which is enhanced by the provisioning of alternative food, refuges, and reproduction sites. In this study, the usefulness of four flowering service plants (Lobularia maritima, Calendula officinalis, Coreopsis grandiflora, and Achillea millefolium) is evaluated for aphid infestation levels and aphid natural enemy abundances. Aphid levels were consistently lower in oleander plots surrounded by service plants. Natural enemy abundances tended to be higher in plots surrounded by service plants, but significant differences could not be found until the fourth year of the study, when more lacewings, total predators, and mummies were higher in plots surrounded by service plants. On these plots, hoverflies, ladybeetles, and lacewings were the most common predators. Paragus sp. and Hippodamia variegata were the prevalent hoverfly and ladybeetle species, respectively. The potential toxicity effect on the prevalence of natural enemy species is discussed. On service plants, significantly more hoverflies were recorded on L. maritima than on C. officinalis and C. grandiflora, and more true bugs were recorded on C. officinalis and A. millefolium than on L. maritima or C. grandiflora. Our results suggest that planting service plants (such as sweet alyssum, marigold, or yarrow) surrounding oleanders can improve conservation biological control by enhancing the abundance of aphid natural enemies and thus a reduction of the abundance of A. nerii.

Comparison between the exotic Coreopsis grandiflora and native Dendranthema indicum across variable nitrogen deposition conditions

Comparison between the exotic Coreopsis grandiflora and native Dendranthema indicum across variable nitrogen deposition conditions

Physiological and rhizospheric response characteristics to cadmium of a newly identified cadmium accumulator Coreopsis grandiflora Hogg. (Asteraceae)

Screening for superior cadmium (Cd) phytoremediation resources and uncovering the mechanisms of plant response to Cd are important for effective phytoremediation of Cd-polluted soils. In this study, the characteristics of Coreopsis grandiflora related to Cd tolerance and accumulation were analyzed to evaluate its Cd phytoremediation potential. The results revealed that C. grandiflora can tolerate up to 20 mg kg−1 of Cd in the soil. This species showed relatively high shoot bioconcentration factors (1.09–1.85) and translocation factors (0.46–0.97) when grown in soils spiked with 5–45 mg kg–1 Cd, suggesting that C. grandiflora is a Cd accumulator and can potentially be used for Cd phytoextraction. Physiological analysis indicated that antioxidant enzymes (i.e., superoxide dismutase, peroxidase, and catalase) and various free amino acids (e.g., proline, histidine, and methionine) participate in Cd detoxification in C. grandiflora grown in soil spiked with 20 mg kg–1 of Cd (Cd20). The overall microbial richness and diversity remained similar between the control (Cd0) and Cd20 soils. However, the abundance of multiple rhizospheric microbial taxa was altered in the Cd20 soil compared with that in the Cd0 soil. Interestingly, many plant growth-promoting microorganisms (e.g., Nocardioides, Flavisolibacter, Rhizobium, Achromobacter, and Penicillium) enriched in the Cd20 soil likely contributed to the growth and vitality of C. grandiflora under Cd stress. Among these, some microorganisms (e.g., Rhizobium, Achromobacter, and Penicillium) likely affected Cd uptake by C. grandiflora. These abundant plant growth-promoting microorganisms potentially interacted with soil pH and the concentrations of Cd and AK in soil. Notably, potassium-solubilizing microbes (e.g., Rhizobium and Penicillium) may effectively solubilize potassium to assist Cd uptake by C. grandiflora. This study provides a new plant resource for Cd phytoextraction and improves our understanding of rhizosphere-associated mechanisms of plant adaptation to Cd-contaminated soil.

Effects of Landscape and Local Factors on the Diversity of Flower-Visitor Groups under an Urbanization Gradient, a Case Study in Wuhan, China

Urbanization is one of the primary forces driving worldwide pollinator decline. Moderate urban expansion with appropriate green space planning can help in maintaining pollinator diversity and pollination service. We investigated the relative effects of landscape and local factors on the diversity of flower-visitor functional groups in a moderately urbanized city, Wuhan, located in central China. We found that the proportion of impervious surface had no significant effect on the number of visitations, but it was negatively associated with the diversity of flower-visitor groups. The number of visitations by Halictidae and Lepidoptera correlated positively with local flower density and flowering plant species richness, respectively. Flowering plant species richness was also positively correlated with the diversity of flower-visitor groups. The proportion of green space was negatively associated with the visitation number of Muscidae and the overall diversity of flower-visitor groups, revealing the potential influence of green space quality on pollinator assemblage. The pollination networks under three urbanization levels (with a total of 11 flower visitor groups and 43 plant species) were asymmetric, highly nested, and generalized. The suburb sites contained the highest diversity of interactions. Core flowering plants (Oenothera speciosa, Coreopsis grandiflora and Cyanus segetum) are exotic species with attractive flowers. Improving green space quality (high flower density and flowering plant species richness) and using attractive native flowering plants (Nandina domestica, Rosa chinensis, Astragalus sinicus, Cirsium arvense var. integrifolium, and Zabelia biflora) would enhance the function of urban green space to maintain pollinator diversity and ecosystem stability.

Display Complexity Affects Visual Processing of Horticultural Plant Retail Displays

Abstract Attractive displays can stimulate sales in the retail setting. With most plants still sold in physical retail outlets, the influence of display layout on visual behavior and purchasing is of interest to academicians and practitioners. Using a within-subjects in-lab experiment and eye tracking technology, we explored how the cognitive load imposed by horticultural retail displays affects visual attention and choice. Display layouts were varied for six choice tasks in which participants indicated their most preferred alternative and their likelihood-to-purchase that alternative. Our study suggests that as the number of plant genera increases, perceived display complexity increases, and participants ignore a larger percentage of the products in the display while spending a lower percentage of their gaze sequence fixated on their choice product. Implications for retailers include increasing horizontal merchandising, reducing vertical merchandising, and diversifying the product mix in the display. Index words: cognitive load, eye tracking, marketing, retail displays, complexity. Species used in this study: Buddleia davidii Franch. ‘Little Nugget', Campanula portenschlagiana Resholt (Roem. & Schult.), Coreopsis grandiflora L. ‘Sunburst', Echinacea purpurea Moench ‘Delicious Candy', Hydrangea paniculata L. ‘Limelight', Lupinus spp. L. ‘Tutti Fruitti', Sempervivum cv. L, Spirea japonica L. ‘Double Play Red'.

Effects of light intensity and nitrogen deposition on ecophysiological characteristics of Coreopsis grandiflora1

Light heterogeneity commonly occurs in natural environments, and N deposition has increased sharply in recent decades, affecting both the growth and invasion of exotic plants. We used an exotic species, Coreopsis grandiflora, distributed in natural and urban areas throughout China, to study the combined effects of light exposure and N addition on leaf physiology, height, crown area, total biomass (TB), and phenotypic plasticity. We exposed C. grandiflora seedlings to one of three light (15, 65, and 100% of full irradiation) and one of three nitrogen treatments (0, 8, and 20 g N m–2 yr–1). The shade significantly increased leaf chlorophyll, N, and P concentrations, aboveground biomass allocation, and specific leaf area, allowing plants to capture more light, which did not result in a change in TB, indicating that C. grandiflora seedlings have shade tolerance. Nitrogen addition generally increased the TB, leaf biomass, crown area and leaf N concentration. In addition, N supply did not increase TB of C. grandiflora in the shade. For approximately half of the traits measured, the phenotypic plasticities of C. grandiflora responding to light differ greatly from those responding to N addition. Under light and N deposition treatments, photosynthetic N use efficiency had higher phenotypic plasticity than other leaf physiological traits, whereas the maximum quantum yield of photosystem II, leaf N, and P concentrations had lower phenotypic plasticity, suggesting that hierarchical plasticity occurs among the various leaf physiological traits. Light intensity increased the plasticity of C. grandiflora in response to N deposition. Thus, with high plasticity, invasiveness of C. grandiflora may increase under high N deposition and illumination conditions.

A high daily light integral can influence photoperiodic flowering responses in long day herbaceous ornamentals

Commercial producers of herbaceous ornamentals have reported that long-day plants sometimes flower under short-day conditions when the photosynthetic daily light integral (DLI) is high, but little research-based information is available to support the phenomenon. We grew seedlings of tickseed (Coreopsis grandiflora), echinacea (Echinacea × hybrida), lavender (Lavandula angustifolia), lobelia (Lobelia × speciosa), and salvia (Salvia longispicata × farinacea) in a controlled-environment greenhouse. They were then transplanted and grown under photoperiods of 10, 11, 12, 13, 14, or 15 h under an average DLI of 5.3 or 13.4 mol·m−2·d−1 and at an air temperature setpoint of 20 °C. Based on flowering percentage, the DLI influenced the photoperiodic responses in four species. Flowering percentages of tickseed, echinacea, lavender, and lobelia were lower under the low DLI compared with the high DLI under photoperiods <11, <12, <12, or <13 h, respectively. Time to flower for all species generally decreased as photoperiod increased. In addition, most species had more inflorescences and were more compact under the higher DLI. Under the high DLI, all echinacea and lobelia plants flowered under all photoperiods tested. Salvia flowered in all treatments, and formed fewer leaves before flowering under photoperiods ≥14 h compared to other photoperiods. However, under the higher DLI, salvia plants took slightly longer to flower under 15 h than 14 h. To clarify its photoperiodic response, we performed an additional experiment with salvia the following year. At germination, seedlings were placed under photoperiods of 14, 15, or 16 h, or a 9 h day with a 4-h night interruption and received an average DLI of 9.2 mol·m−2·d−1. Flowering was delayed under the 16 h and night-interruption treatments compared to under 14 and 15 h. We conclude that photoperiod and DLI interact to influence flowering of at least some long-day plants and that salvia has an intermediate photoperiodic flowering response.

Identification of Amino Acid Residues Responsible for C-H Activation in Type-III Copper Enzymes by Generating Tyrosinase Activity in a Catechol Oxidase.

Tyrosinases (TYRs) catalyze the hydroxylation of phenols and the oxidation of the resulting o‐diphenols to o‐quinones, while catechol oxidases (COs) exhibit only the latter activity. Aurone synthase (AUS) is not able to react with classical tyrosinase substrates, such as tyramine and l‐tyrosine, while it can hydroxylate its natural substrate isoliquiritigenin. The structural difference of TYRs, COs, and AUS at the heart of their divergent catalytic activities is still a puzzle. Therefore, a library of 39 mutants of AUS from Coreopsis grandiflora (CgAUS) was generated and the activity studies showed that the reactivity of the three conserved histidines (HisA2, HisB1, and HisB2) is tuned by their adjacent residues (HisB1+1, HisB2+1, and waterkeeper residue) either to react as stronger bases or / and to stabilize a position permissive for substrate proton shuffling. This provides the understanding for C−H activation based on the type‐III copper center to be used in future biotechnological processes.

Blue radiation signals and saturates photoperiodic flowering of several long-day plants at crop-specific photon flux densities

When the natural photoperiod is short, electric lighting can be used to promote flowering of a wide range of ornamental long-day plants (LDP) grown inside greenhouses. A combination of red (R; 600–700 nm) and far-red (FR; 700–800 nm) radiation is effective when delivered at a low intensity (1–2 μmol m−2 s−1), but recent research shows blue (B; 400–500 nm) radiation can also be effective. We performed an experiment, replicated in time, that identified the B photon flux density that controlled flowering of four LDPs when delivered as a 4-h night interruption (NI) or 7-hour day extension (DE) during an otherwise 15-h night. Seedlings of four annual bedding plants were initially grown under a 9-h day, and then were transferred to one of seven lighting treatments, where subscripts indicate their photon flux densities: R+FR2–3 NI; B5, B15, or B30 NI; and B5, B15, or B30 DE. At a sufficiently high photon flux density, B radiation delivered as a 4-h NI or 7-h DE promoted flowering of all four LDPs. All species exhibited a dose-response relationship between B photon flux density and flowering time. The threshold B photon flux density above which flowering was promoted varied among the four LDPs, and was 5 μmol m−2 s−1 for coreopsis (Coreopsis grandiflora) and snapdragon (Antirrhinum majus) and 15 μmol m−2 s−1 for petunia (Petunia × hybrida) and rudbeckia (Rudbeckia hirta). A B photon flux density of 15 or 30 μmol m−2 s−1 delivered as an NI or DE was usually as effective as 2–3 μmol m−2 s−1 of R + FR radiation for all LDPs tested. We conclude that while flowering of LDPs is more sensitive to R + FR than B radiation, relatively low B photon flux densities are perceived as a long day when delivered as a DE or NI.

Multilocus gene characterization of phytoplasmas in 16SrII-D subgroupassociated with Coreopsis grandiflora little leaf disease in India

In September 2018 symptoms of little leaf were observed in Coreopsis grandiflora located in flower nurseries at IARI campus, New Delhi. Little leaf and phyllody symptoms were also observed on nearby growing ornamental hedge plants belonging to Duranta genus and in a weed (Parthenium hysterophorus). Amplicons of ∼1.25 kb were consistently amplified with nested PCR assays using DNA extracted from the symptomatic Coreopsis, Duranta and Parthenimum samples, while no amplification was observed with any of the asymptomatic samples of the same species. Leafhoppers (Empoasca sp.) collected from the nurseries of Coreopsis were also found phytoplasma positive using the same nested PCR protocol. BLAST and pair wise sequence comparison of the R16F2n/R2 region of 16S rRNA gene of C. grandiflora little leaf (CGLL), Duranta sp. little leaf (DLL), P. hysterophorus phyllody (PHP) and Empoasca sp (Em) revealed 99.8% sequence identity with the ‘Candidatus Phytoplasma australasia’ sequence. Phylogeny and virtual RFLP analysis with iPhyclassifier confirmed the affiliation to ‘Ca. P. australasia’, subgroup 16SrII-D of all these phytoplasma strains. Amplicons of the expected size were also consistently amplified from these strains with primers specific to 16SrII group of SAP11, imp and tuf genes. All the amplified products were sequenced and confirmed the phytoplasma affiliation to 16SrII-D subgroup. This is the first report of 16SrII-D group phytoplasma presence in C. grandiflora showing little leaf disease.

Radiation Intensity and Quality from Sole-source Light-emitting Diodes Affect Seedling Quality and Subsequent Flowering of Long-day Bedding Plant Species

Previous research has shown high-quality annual bedding plant seedlings can be produced in controlled environments using light-emitting diode (LED) sole-source lighting (SSL). However, when only red and blue radiation are used, a delay in time to flower may be present when seedlings of some long-day species are subsequently finished in a greenhouse. Thus, our objective was to evaluate the effects of various radiation qualities and intensities under SSL on the morphology, nutrient uptake, and subsequent flowering of annual bedding plant seedlings with a long-day photoperiodic response. Coreopsis (Coreopsis grandiflora ‘Sunfire’), pansy (Viola ×wittrockiana ‘Matrix Yellow’), and petunia (Petunia ×hybrida ‘Purple Wave’) seedlings were grown at radiation intensities of 105, 210, or 315 µmol·m−2·s−1, achieved from LED arrays with radiation ratios (%) of red:blue 87:13 (R87:B13), red:far-red:blue 84:7:9 (R84:FR7:B9), or red:green:blue 74:18:8 (R74:G18:B8). Four-week-old seedlings were subsequently transplanted and grown in a common greenhouse environment. Stem caliper, root dry mass, and shoot dry mass of seedlings generally increased for all three species as the radiation intensity increased from 105 to 315 µmol·m−2·s−1, regardless of radiation quality. Similarly, stem length of all three species was generally shorter as the radiation intensity increased. Macro- and micronutrient concentrations were also generally lower as the radiation intensity increased for all three species. Pansy seedlings grown under R84:FR7:B9 flowered an average of 7 and 5 days earlier than those under R87:B13 and R74:G18:B8, respectively. These results provide information regarding the specific radiation parameters from commercially available LEDs necessary to produce high-quality seedlings under SSL, with radiation intensity appearing to be the dominant factor in determining seedling quality. Furthermore, the addition of far-red radiation can reduce time to flower after transplant and allow for a faster greenhouse turnover of some species with a long-day photoperiodic response.

Herbaceous Perennial Seed Germination and Seedling Growth in Biochar-amended Propagation Substrates

The first objective of this study was to assess the effects of coconut shell biochar in propagation substrate on seed germination and seedling growth of Coreopsis grandiflora (Hogg ex Sweet) ‘Early Sunrise’, Leucanthemum ×superbum (Bergman ex J. Ingram) ‘Silver Princess’, and Eschscholzia californica (Cham.). Cornell seed germination mix was amended with the biochar (0%, 5%, 10%, 20%, or 40%, v/v). Seed germination and seedling growth were determined during a 21-day period in two germination rooms. This particular biochar amendment did not affect final germination percentage for any of the species. All three species had seedling shoot and primary root length growth with low to moderate positive correlation (r = 0.33–0.54) with coconut shell biochar amendment volume. Coreopsis seedling dry weight was significantly higher with 40% biochar than the control (P ≤ 0.05). The second objective of the study was to compare digitally collected data with manually collected data. Two-dimensional scans of Coreopsis and Leucanthemum seedlings were collected. Seedling dry weight (mg) and seedling length (mm) predicted seedling two-dimensional area for Coreopsis (R2 = 0.73, P &lt; 0.001) and Leucanthemum (R2 = 0.87, P &lt; 0.001). Digitally traced shoot and root lengths were strongly positively correlated (r = 0.99–0.97) with manual ruler measurements, suggesting that digital imaging could replace manual length measurements. The results of this study suggest inclusion of this particular coconut shell biochar in seed germination, and establishment substrates can have neutral or positive effects on herbaceous perennial germination and establishment.

Investigating the efficacy of white light-emitting diodes at regulating flowering of photoperiodic ornamental crops

Under natural short days (SDs), low-intensity lighting during the middle of a night (night interruption, NI) can control flowering of daylength-sensitive ornamentals. Red (R, 600-700 nm) and far-red (FR, 700-800 nm) radiation is primarily absorbed by phytochromes that mediate flowering, whereas blue (B, 400-500 nm) radiation typically has less photoperiodic relevance, at least at a low intensity. White (W) light-emitting diodes (LEDs) emit photons over a broad spectrum; however to our knowledge, their efficacy at regulating flowering has not been published. We investigated whether white LEDs controlled flowering of five long-day plants [calibrachoa (Calibrachoa × hybrida), coreopsis (Coreopsis grandiflora), petunia (Petunia × hybrida), rudbeckia (Rudbeckia hirta), and snapdragon (Antirrhinum majus)] and two SD plants [chrysanthemum (Chrysanthemum × morifolium) and marigold (Tagetes erecta)]. Plants were grown in a greenhouse at 20°C under 9-h SDs with or without 4-h NIs from R, B+R, cool-W, warm-W, or R+W+FR LEDs. Irradiance at plant canopy was adjusted to approximately 2 µmol m-2 s-1 between 400 and 800 nm. Compared with SD, all NIs similarly promoted flowering of calibrachoa and rudbeckia; however, only R+W+FR promoted flowering of snapdragon. NIs without FR radiation (i.e., R, B+R, cool-W, and warm-W) accelerated flowering of coreopsis and petunia, but flowering under R+W+FR was 11-16% earlier than under the other NIs. R+W+FR was less effective than the other NIs at inhibiting flowering of chrysanthemum and marigold. Cool-W and warm-W had similar effects on flowering and development of all crops. Plant height of calibrachoa, coreopsis, and marigold at flowering was greatest under R+W+FR; however, stem length of the other crops was similar under all NIs. We conclude that W LEDs inhibited flowering of SD plants and were as effective as R or R+W+FR radiation at promoting flowering of some, but not all, long-day plants.

Moderate-intensity blue radiation can regulate flowering, but not extension growth, of several photoperiodic ornamental crops

Lighting that creates an effective phytochrome photoequilibrium at the end of the day (day extension) or during the middle of the night (night interruption) can regulate flowering of photoperiodic ornamentals grown under short days. In addition to phytochrome regulation, blue (B) radiation can elicit cryptochrome-mediated photoperiodic responses, such as flowering and stem growth. Although B radiation at a low intensity does not influence plant development, we postulated that it could regulate flowering at a higher intensity while acting as a plant growth regulator. We grew five long-day plants [calibrachoa (Calibrachoa×hybrida), coreopsis (Coreopsis grandiflora), petunia (Petunia×hybrida), rudbeckia (Rudbeckia hirta), and snapdragon (Antirrhinum majus)] and two short-day plants [chrysanthemum (Chrysanthemum×morifolium) and marigold (Tagetes erecta)] in a controlled-environment greenhouse under a 9-h short day with or without 5.5-h day-extension or 4-h night-interruption lighting from light-emitting diodes. B radiation was delivered at 0, 1 (low), 15, or 30 (moderate) μmolm−2s−1, with or without low red (R)+white+far-red (FR) radiation. Moderate B radiation created long days in all crops as effectively as low R+white+FR radiation. Flowering of calibrachoa and petunia, but not other crops, was 2–4d earlier when moderate B radiation was added to low R+white+FR radiation. At a sufficiently high intensity, B radiation possibly mediated these flowering responses through interactions of signaling molecules and multiple photoreceptors besides phytochromes. There were few or no morphological differences among flower-inducing treatments in most crops. We conclude that night-interruption lighting with moderate B radiation, alone and when added to low R and FR radiation, can regulate flowering, but does not inhibit extension growth, of a wide range of photoperiodic crops.

Effect of Bioregulators on Chlorophyll Content at Matthiola incana and Scabiosa atropurpurea

During our experiment the effect of chlorocholine chloride, Caramba, Cultar, Regalis and Toprex bioregulators were examined on some annual ornamental species. The species used for the experiment were Coreopsis grandiflora, Godetia grandifolra , Scabiosa atropurpurea and Matthiola incana. The aim of this work was to produce marketable, bushy habitat annual plants as flowering pot plants with the use of retardants. The experiment was carried out from April to September 2013, plants were treated beweekly. Â It was found that all the treatments had effect on the plants but the result depended on the species. In the case of Coreopsis grandiflora the best dwarfing effect was obtained with Regalis 0,25% and Caramba at 0,05% concentration, the maximum shorten rate was 50%. In the case of the other examined species intensive retardant effect was observed with the spray of Cultar, Toprex or Caramba. Best results were obtained by the treatment of Matthiola incana , all the chemicals resulted compact, bushy, decorative plant habitat, Regalis WG had the best results among the bioregulators. The chlorophyll content of two plant species was measured: Scabiosa atropurpurea and Matthiola incana . The chlorophyll content of the leaves was reduced by using growth retardants. The rate of decrease depended on the regulator type and the plant species. By cultivation for market is mandatory to do trial management before use. Â Â

In situ formation of the first proteinogenically functionalized [TeW6O24O2(Glu)]7- structure reveals unprecedented chemical and geometrical features of the Anderson-type cluster.

The chemistry of polyoxometalates (POMs) in a protein environment is an almost unexplored but highly relevant research field as important biological and pharmacological attributes of certain POMs are based on their interactions with proteins. We report on the A-type Anderson-Evans polyoxotungstate, [TeW6O24]6- (TEW), mediated crystallization of Coreopsis grandiflora aurone synthase (cgAUS1) using ∼0.24 mM protein and 1.0 mM TEW. The 1.78 Å crystal structure reveals the covalent binding of TEW to the protein under the formation of an unprecedented polyoxotungstate cluster, [TeW6O24O2(Glu)]7- (GluTEW). The polyoxotungstate-protein complex exhibits the first covalent bond between a protein and the A-type Anderson-Evans cluster, an archetype where up to now no hybrid structures exist. The polyoxotungstate is modified at two of its six addenda tungsten atoms, which covalently bind to the carboxylic oxygen atoms of glutamic acid (Glu157), leading to W-O distances of ∼2.35 Å. This ligand substitution reaction is accompanied by a reduction of the coordination number of two μ3 polyoxotungstate oxygen atoms. This is so far unique since all known hybridizations of the Anderson-Evans POM with organic units have been obtained via the functionalization of the B-type Anderson-Evans structure through its bridging oxygen atoms. The structure reported here proves the reactivity of this POM archetype's addenda atoms as it has been administered into the protein solution as a pre-assembled cluster. Moreover, the novel cluster [TeW6O24O2(Glu)]7- displays the great versatility of the Anderson-Evans POM class.

Crystallization and preliminary crystallographic analysis of latent, active and recombinantly expressed aurone synthase, a polyphenol oxidase, from Coreopsis grandiflora.

Aurone synthase (AUS), a member of a novel group of plant polyphenol oxidases (PPOs), catalyzes the oxidative conversion of chalcones to aurones. Two active cgAUS1 (41.6 kDa) forms that differed in the level of phosphorylation or sulfation as well as the latent precursor form (58.9 kDa) were purified from the petals of Coreopsis grandiflora. The differing active cgAUS1 forms and the latent cgAUS1 as well as recombinantly expressed latent cgAUS1 were crystallized, resulting in six different crystal forms. The active forms crystallized in space groups P2(1)2(1)2(1) and P12(1)1 and diffracted to ∼ 1.65 Å resolution. Co-crystallization of active cgAUS1 with 1,4-resorcinol led to crystals belonging to space group P3(1)21. The crystals of latent cgAUS1 belonged to space group P12(1)1 and diffracted to 2.50 Å resolution. Co-crystallization of recombinantly expressed pro-AUS with the hexatungstotellurate(VI) salt Na6[TeW6O24] within the liquid-liquid phase separation zone significantly improved the quality of the crystals compared with crystals obtained without hexatungstotellurate(VI).