Marigold Flowers Research Articles

Recombinant Synechococcus elongatus PCC 7942 for improved zeaxanthin production under natural light conditions

Cyanobacteria are globally recognized as potential photosynthetic platform cell factories for production of value-added chemicals. Carotenoids are industrially important fine chemicals used in food, pharmaceutical and health-care products. Zeaxanthin has emerged as a high value xanthophyll carotenoid that exhibits superior antioxidant properties over many other carotenoids. Traditionally sourced from plants like marigold flowers wherein, zeaxanthin co-occurs with lutein. Therefore, there is a need for isolated production system for zeaxanthin on account of difficulties in separation of zeaxanthin from lutein due to their very similar molecular structures. Synechococcus elongatus PCC 7942 (PCC 7942) is a cyanobacterium that is known to synthesize zeaxanthin as one of the predominant cellular carotenoids and does not possess pathway genes for lutein production. In order to construct a system capable of industrial production of zeaxanthin, we genetically modified PCC 7942 (Synechococcus 79R48) to improve β‑carotene flux towards zeaxanthin synthesis by cloning CrtR (β‑carotene oxygenase) gene from Synechococcus elongatus PCC 7002 through homologous recombination. This strategy effectively enhanced the yield (mg/g DCW) of zeaxanthin in the transformants. Moreover, to increase zeaxanthin titer (mg/L), an operon construct was synthesized where a heterologous gene GalP (Hexose-H+ symporter) from E. coli MG1655 was cloned downstream of CrtR (Synechococcus 79RG48) which facilitated inherently obligate photoautotrophic WT PCC 7942 cells to uptake extracellular glucose in transformants, thereby increasing biomass productivity. Autotrophically grown cells yielded 9.02 ± 1.10 mg/g DCW of zeaxanthin while under mixotrophy the yield was 8.09 ± 0.19 mg/g DCW, which was 2-fold improvement over the wild type. The volumetric productivities of the transformants were 1.18 ± 0.17 mg/L·d and 1.8 ± 0.06 mg/L·d under autotrophic and mixotrophic conditions, respectively while WT produced 0.58 ± 0.02 mg/L·d. The work was successfully able to demonstrate that the modifications resulted in, enhanced production of lutein-free zeaxanthin in the cyanobacterial system.

Marigold carotenoids: Much more than lutein esters

Carotenoids constitute a large group of lipophilic pigments whose health-promoting benefits have been widely recognized. Hydroxy-containing carotenoids can be found in both free form or esterified with fatty acids in several plant matrices, but the native carotenoid profile is overall poorly explored due to the difficulty of analyzing carotenoid esters. One of the main natural sources of carotenoids is the marigold flower, which has been extensively used by the industry for the production of food colorants or supplements, both often manufactured with no saponification process. Although lutein esters are well established as the major compounds naturally found in marigold petals and their products, carotenoid esters other than the lutein ones have not been extensively examined. We carried out a comprehensive identification of carotenoids and carotenoid esters from marigold petals by LC-DAD-(APCI+)MS/MS. Whereas 18 carotenoids were identified in the saponified extract, 56 were identified when no saponification procedure was carried out: 6 free carotenoids, 20 monoesters and 30 diesters. This is the first time that esters of zeaxanthin, violaxanthin, auroxanthin, zeinoxanthin and β-cryptoxanthin are identified in marigold. The structural information obtained through characteristic fragmentation patterns and diagnostic fragments in MS and MS/MS spectra (APCI+) sustained the differentiation between carotenoid esters with similar characteristics. Therefore, the separation of carotenoids by reversed-phase liquid chromatography using C30 columns in combination with DAD and APCI-MS/MS detection allowed high sensitivity and selectivity for carotenoid ester analysis.

Highly regioselective enzymatic synthesis of lutein-3-monoesters

Lutein, a xanthophyll carotenoid abundant in marigold flowers (Tagetes spp.), is found in the form of ester derivatives of fatty acids. Herein we present an enzymatic approach for the regioselective synthesis of 3-O-acyl monoester lutein derivatives (β-ionone selectivity, up to 17:1), using a lipase (Novozyme 435, immobilized CALB), and vinyl carboxylates (vinyl propionate and stearate) as acyl donors. The regioselectivity arises from the highly stereoselective feature of CALB. This methodology addresses the long-standing problem of regioselective monoesterification of lutein, potentially enabling novel, semisynthetic routes to other monoester xanthophyll carotenoids.

A thermal water microalga: Eutetramorus planctonicus as a promising source of fatty acids and lutein

This paper explores the biotechnological potential of the Eutetramorus planctonicus. This thermal water microalga was isolated and cultivated in two media with different concentrations of nutrients to evaluate the maximum biomass yield, fatty acids, and lutein profiles. From the less nutrient medium to the more nutrient medium, the biomass productivity was 31–71 mg L−1 day−1, the percentage of fatty acids was 15.3–7.7%, the percentage of lutein was 0.46–1.22%, respectively. Media with a lower concentration of nutrient favor fatty acid production, but negatively affect the lutein and biomass productions. In comparison with higher plants, E. planctonicus produced up to 9 times more fatty acids than soybean and up to 11 times more lutein than Marigold flowers, which are the conventional source of these substances. The microalgae E. planctonicus is an excellent source of lutein that could be exploited by the food and pharmaceutical industries. Moreover, E. planctonicus is a good source of biomass and fatty acids. All these characteristics found in just one microalga species can make the process of bioproducts production cheaper.

Pemanfaatan Tanaman Bunga Marigold dan Kacang Hias Terhadap Populasi Arthropoda pada Tanaman Padi Sawah

Penelitian tentang Pemanfaatan tanaman bunga marigold dan kacang hias terhadap populasi arthropoda pada tanaman padi sawah untuk mengetahui populasi arthropoda pada tanaman padi sawah dengan memanfaatkan tanaman refugia sebagai tempat singgah musuh alami dan sebagai sumber pakan musuh alami. Tujuan dari penelitian ini dilakukan untuk mengetahui peranan refugia yaitu bunga marigold (Tagetes erecta L.), dan kacang hias (Arachis pintoi) sebagai mikrohabitat musuh alami, dalam upaya Pengelolaan Hama Terpadu (PHT) dalam budidaya padi. Penelitian ini dilaksanakan selama 5 bulan, yaitu mulai bulan November 2017 sampai bulan Maret 2018, bertempat di lahan Desa Antirogo, Kecamatan Sumbersari, Kabupaten Jember. Penelitian ini dilakukan dengan menggunakan tiga petak lahan penelitian berukuran 50 m2. Tiga petak lahan yaitu petak pertama perlakuan refugia bunga Marigold, petak kedua perlakuan refugia Kacang Hias, dan petak ketiga tanpa refugia. Data hasil penelitian dianalisis secara statistik menggunakan uji t. Hasil penelitian menunjukkan bahwa pemanfaatan tanaman bunga Marigold dan Kacang Hias terhadap populasi arthropoda pada tanamana padi sawah diketahui populasi tertinggi musuh alami terdapat pada petak tanaman padi dengan refugia kacang hias sebanyak 217, dengan refugia Marigold populasi musuh alami sebanyak 156 sedangkan populasi terendah musuh alami terdapat pada petak tanaman padi tanpa refugia sebanyak 140. Penggunaan bunga marigold dan kacang hias berpengaruh terhadap populasi musuh alami.

Cosolvent effect of ethanol on the solubility of lutein in supercritical carbon dioxide

This contribution presents new high-pressure solubility data of solid trans-lutein in pure carbon dioxide (CO2), and mixtures of CO2 and ethanol. The cosolvent effect of ethanol was determined by comparing lutein solubility between the ternary (CO2 + ethanol + lutein) and binary (CO2 + lutein) systems at (313, 323, and 333) K and from (18.70 to 33.55) MPa. 92% pure lutein was isolated from marigold flower petals. Solubility was measured using a dynamic-analytical method with recirculation and online analysis of the CO2-rich phase. The solubility of lutein in pure and ethanol-modified CO2 increased with system temperature and pressure. Solubilities in pure CO2 ranged from 0.82 10−6 mol mol−1 at (313 K and 18.70 MPa) to 2.45 10−6 mol mol−1 at (333 K and 32.91 MPa). The highest solubility of lutein in CO2 experimentally measured was 4.02 10−6 mol mol−1 at (333 K and 32.91 MPa) when adding 0.0211 mol mol−1 of ethanol.

Identification and quantitative determination of the flavonoids of the complex dense extract of st. john's wort herb and pot marigold flowers

Common Saint-John's wort (Hypericum perforatum) and pot marigold (Calendula officinalis) are rich in such biologically active substances (BAS) as carotene, ascorbic acid, essential oils, vitamins, tannin and resinous substances, as well as flavonoids that bear evident wound healing properties and antiulcerous properties.
 The object of this study was BAR composition of the complex dense herb extract of St. John's wort and flowers of marigolds (1:10). In order to introduce a new herbal substance into medical practice, it is necessary to develop methods for its identification and quantification.
 The TLC [thin layer chromatography] method was used to identify the BAR in the extract under study, and the method of absorption spectrophotometry was proposed for quantification of the content of flavonoids.
 As a result of the conducted research, there were selected characteristic substances - identification markers of the extract, the choice of which was in accordance with the requirements of the SPF on the quality of the herb of St. John's wort and the flowers of pot marigold, and there was indicated the position and coloring of the zones in the chromatographic profile of the tested extract solution. Such approach will enable objective identification of the extract as a substance and as an active pharmaceutical ingredient in the formulation.
 The criterion for quantitative standardization of the complex dense extract is the content of the amount of flavonoids not less than 1.5% in terms of hyperoside and dry substance.

Facile biosynthesis of reduced graphene oxide nanostructures via reduction by tagetes erecta (marigold flower) plant extract

In this paper, we report the development of a new green, eco-friendly pathway for the synthesis of reduced graphene oxide (RGO). In a typical experiment, graphene oxide (GO) was prepared by the oxidation of graphite powder using Hummer’s method. Prepared GO was then subjected to reduction by using extract of Tagetes erecta (Marigold flower). The samples were characterized by various techniques such as X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy and Raman spectroscopy. RGO synthesized in this work is being probed for diverse applications including biomedical applications.

One-step hydrothermal synthesis of marigold flower-like nanostructured MoS2 as a counter electrode for dye-sensitized solar cells

MoS2 thin films with marigold flower-like nanostructures were grown on conductive fluorine-doped tin oxide (FTO) substrates through a one-step hydrothermal synthesis for their application as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). Different MoS2 thin film samples (A–D) were grown on FTO slides using different concentrations of precursors (sodium molybdate and thioacetamide), while keeping the Mo/S molar ratio constant (1:4.6), in all samples. The effect of varying precursor concentrations (3.2–12.6 mM on MoS2 basis) on the structure of the nanostructured thin films and their performance as DSSC-CEs was investigated. Scanning electron microscopy revealed a material with an infolded petal-like morphology. With increasing precursor concentration, the petal-like structures tended to form bunched nanostructures (100–300 nm) resembling marigold flowers. X-ray diffraction analysis, X-ray photoelectron, and Raman spectroscopy studies showed that the thin films were composed of hexagonal MoS2 with good crystallinity. Hall effect measurements revealed MoS2 to be a p-type semiconductor with a carrier mobility of 219.80 cm2 V−1 s−1 at room temperature. The electrochemical properties of the thin films were examined using cyclic voltammetry and electrochemical impedance spectroscopy. The marigold flower-like MoS2 thin films showed excellent electrocatalytic activity towards the I¯/I3¯ reaction and low charge transfer resistance (Rct) values of 14.77 Ω cm−1, which was close to that of Pt electrode (12.30 Ω cm−1). The maximum power conversion efficiency obtained with MoS2 CE-based DSSCs was 6.32%, which was comparable to a Pt CE-based DSSC (6.38%) under one sun illumination. Similarly, the maximum incident photon-to-charge carrier efficiency exhibited by MoS2 CE-based DSSCs was 65.84%, which was also comparable to a Pt CE-based DSSC (68.38%). The study demonstrated that the marigold flower-like nanostructured MoS2 films are a promising alternative to the conventional Pt-based CEs in DSSCs.

Transformation of naturally occurring (3R,3′R,6′R)-lutein and its fatty acid esters to (3 R)-β-cryptoxanthin and (3R,6′R)-α-cryptoxanthin

The objective of this study was to develop straightforward processes that could be applied to the large-scale production of β-cryptoxanthin in an attempt to facilitate investigation of its biological activity. An oleoresin obtained from crude extracts of marigold flowers (Tagetes erecta) with approximately 24% total lutein fatty acid ester content was directly used as starting material for partial synthesis of (3 R)-β-cryptoxanthin under mild reaction conditions at ambient temperature. Therefore, acid-catalyzed deoxygenation of lutein esters from marigold oleoresin followed by hydrogenation in the presence of catalytic amount of platinum (Pt) supported on alumina (5%) at ambient temperature gave a mixture of (3 R)-β-cryptoxanthin fatty acid esters (major) and (3 R,6′R)-α-cryptoxanthin fatty acid esters (minor). Saponification and Z-to-E isomerization of the product followed by crystallization gave a mixture of (3 R)-β-cryptoxanthin as the major product. Similarly, acid-catalyzed hydrogenation of unesterified (3 R,3′R,6′R)-lutein with Pt/alumina in ethyl acetate gave a mixture of (3 R,6′R)-α-cryptoxanthin acetate (minor) in a one-pot reaction. Alkaline hydrolysis and Z-to-E isomerization of the mixture followed by crystallization provided (3 R)-β-cryptoxanthin.

Microwave and enzyme co-assisted aqueous two-phase extraction of polyphenol and lutein from marigold (Tagetes erecta L.) flower

In this study, a novel method of simultaneous extraction and enrichment of total polyphenol (TP) and lutein from marigold flower was developed by microwave and enzyme co-assisted aqueous two-phase extraction (ATPE) (MEAATPE). In this study, ethanol/ammonium sulfate was chosen to construct aqueous two-phase system (ATPS) due to its fine partition and recycling behaviors. The optimal MEAATPE condition was obtained, that is, 28% (w/w), ethanol/20% (w/w) ammonium sulfate, 0.45 U/g enzyme concentration, enzymolysis time of 150 min, enzymolysis temperature of 45 °C, microwave time of 120 s, and microwave power of 270 W, by investigating the effects of ATPS composition and other factors on the yield of target products. Under this optimal condition, the yields of TP and lutein reached 84.61 and 7.32 mg/g with the corresponding recovery rates of 95.35% and 99.85%, respectively. Compared with enzyme-assisted ATPE, microwave-assisted ATPE, ATPE, and Soxhlet extraction (SE), the extraction yield of TP by MEAATPE was the highest, which is 71.14% higher than that of SE. Scanning electron microscopy analysis further showed an optative pretreatment effect of marigold flower powders. Thus, MEAATPE was an efficient, rapid, and environmental-friendly method used for the extraction of natural products.

Effect of plant growth regulators and pinching on growth and flower yield of African marigold (Tagetes erecta L.)

Marigold is one of the commercially exploited flower crop that belong to the family Asteraceae. Presently, in our country the commercial extraction of marigold carotenoids is becoming popular in many states. The production of economical yield and better quality of marigold flowers, requires proper crop management techniques. Crop regulation and flower forcing are important techniques to make the marigold production profitable. This can be done by adopting pinching and application of PGRs. Hence, an experiment was carried out in the Department of Horticulture, in factorial randamized block design replicated thrice with 14 treatments with two F1 hybrids viz., Gold Benz tall and Maxima yellow. The experiment comprised of GA3 @ 50, 100 and 150ppm, NAA @ 50, 100 and 150ppm, MH @ 250, 500 and 750ppm, Alar @ 200, 400 and 600ppm and pinching with untreated control. The study revealed that the growth parameter like plant height, number of laterals per plant, number of leaves per plant were significantly influenced by the application of GA3 and NAA. Among the varieties, Gold Benz tall performed better for all the growth attributes but var. Maxima yellow performed better for the number of laterals per plant. The plant sprayed with of GA3 @ 150ppm registered the maximum plant height (70.44cm), number of laterals per plant (16.13), number of leaves per plant (383.76) and leaf area (113.51cm2) and control evinced the least values in the growth parameters. Application of GA3 and NAA significantly enhanced flowering when compared to control, while pinching delayed flowering. The treatment of GA3 @ 150ppm in both Gold Benz tall (30.13 and 406.21 g plant-1) and Maxima yellow (33.16 and 402.83 g plant-1 recorded maximum number of flowers per plant and flower yield respectively as compared to control. Based on the above results, it is revealed that foliar spray of GA3 @ 150 ppm was found to be superior in increasing the yield of flowers in both the varieties.

Effect of plant growth regulators and pinching on growth and flower yield of African marigold (Tagetes erecta L.)

Marigold is one of the commercially exploited flower crop that belong to the family Asteraceae. Presently, in our country the commercial extraction of marigold carotenoids is becoming popular in many states. The production of economical yield and better quality of marigold flowers, requires proper crop management techniques. Crop regulation and flower forcing are important techniques to make the marigold production profitable. This can be done by adopting pinching and application of PGRs. Hence, an experiment was carried out in the Department of Horticulture, in factorial randamized block design replicated thrice with 14 treatments with two F1 hybrids viz., Gold Benz tall and Maxima yellow. The experiment comprised of GA3 @ 50, 100 and 150ppm, NAA @ 50, 100 and 150ppm, MH @ 250, 500 and 750ppm, Alar @ 200, 400 and 600ppm and pinching with untreated control. The study revealed that the growth parameter like plant height, number of laterals per plant, number of leaves per plant were significantly influenced by the application of GA3 and NAA. Among the varieties, Gold Benz tall performed better for all the growth attributes but var. Maxima yellow performed better for the number of laterals per plant. The plant sprayed with of GA3 @ 150ppm registered the maximum plant height (70.44cm), number of laterals per plant (16.13), number of leaves per plant (383.76) and leaf area (113.51cm2) and control evinced the least values in the growth parameters. Application of GA3 and NAA significantly enhanced flowering when compared to control, while pinching delayed flowering. The treatment of GA3 @ 150ppm in both Gold Benz tall (30.13 and 406.21 g plant-1) and Maxima yellow (33.16 and 402.83 g plant-1 recorded maximum number of flowers per plant and flower yield respectively as compared to control. Based on the above results, it is revealed that foliar spray of GA3 @ 150 ppm was found to be superior in increasing the yield of flowers in both the varieties.

Surface characterisation and reaction kinetics of silver nanoparticles mediated by the leaf and flower extracts of French marigold (Tagetes patula).

In this study, French marigold's leaf and flower were used for the synthesis of silver nanoparticles (SNPs) in order to explore their potentials towards bioreduction of Ag+ to Agᵒ. The as-synthesised SNPs were characterised using UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction, transmission electron microscopy, and zeta-potential analysis. The results obtained showed that the particles are polydispersed with sizes in the range 15.8-42.8 nm. The bioreduction was believed to be due to the amides, aldehyde functional groups, and essential oils present in the extracts as confirmed by the FTIR analysis. The growth mechanism involved in the reaction was studied which revealed oriented attachment (OA) onwards Ostwald ripening in the case of the flower-mediated synthesis and typical OA in the leaf-mediated synthesis. The studied kinetics of the particle formation showed that the reaction is possibly a pseudo-first-order reaction with some diffusion-controlled mechanism which is driven by high surface area to volume ratio in both the leaf- and flower-mediated synthesis.

The preparation and characterization of composite materials by incorporating microspheres into a collagen/hydroxyethyl cellulose matrix

Natural ingredients and innovative delivery systems are most widely used in the development and production of many skin care products in the fields of cosmetics and pharmacy. The main goal of this study was to design, prepare and characterize materials with microspheres incorporated into a porous polymer matrix. This study covered the preparation of 3D collagen/hydroxyethyl cellulose materials with incorporated gelatin or collagen-gelatin microspheres. The structures of the obtained materials were characterized using SEM and FTIR. Additionally, porosity, density, mechanical properties, swelling properties and resistance to degradation were measured. The obtained materials were loaded with pot marigold (Calendula officinalis) flower extract and the in vitro release was studied. The data indicated that the incorporation of gelatin and collagen-gelatin microspheres into polymeric matrices decreased their porosity and swelling properties, however, it increased their density and stiffness as well as their association with pot marigold flower extract. These materials may become the basis for a cosmetic or dermatological formulation.

Morphology and Flowering Responses of Four Bedding Plant Species to a Range of Red to Far Red Ratios

In greenhouse ornamental crop production, bedding plants grown below high densities of hanging baskets (HBs) tend to be of lower quality. Hanging basket crops can decrease the red to far red ratio (R:FR) of the growing environment below; however, the extent to which decreased R:FR affects plant morphology and flowering of the lower-level crops is unknown. The present study examined effects of R:FR on morphology and flowering of marigold ‘Antigua Orange’ (Tagetes erecta), petunia ‘Duvet Red’ (Petunia ×hybrida), calibrachoa ‘Kabloom Deep Blue’ (Calibrachoa ×hybrida), and geranium ‘Pinto Premium Salmon’ (Pelargonium ×hortorum). Five R:FR light treatments were provided ranging from R:FR 1.1 (representing unfiltered sunlight) to R:FR 0.7 (representing shaded conditions under HBs) using light-emitting diodes (LEDs) in growth chambers, each with identical photosynthetically active radiation (PAR) (400–700 nm) and FR added to achieve the target R:FR ratio. Two experiments using the same R:FR treatments were conducted with day/night temperature regimes of 20 °C/18 °C and 25 °C/21 °C, respectively. In the second experiment, a fluorescent light treatment was included. The results of the second experiment were more dramatic than the first, where reducing R:FR from 1.1 to 0.7 increased height by 11%, 22%, and 32% in marigold, petunia, and calibrachoa, respectively, and increased petiole length in geranium by 10%. Compared with R:FR 1.1, the R:FR 0.7 shortened the time to the appearance of first flower bud by 2 days in marigold, whereas flowering was minimally affected in other species. Compared with pooled data from the LED treatments, fluorescent light increased relative chlorophyll content for all species, reduced height in marigold, petunia, calibrachoa, and geranium by 26%, 67%, 60%, and 48%, and reduced stem dry weight by 28%, 39%, 21%, and 31%, respectively. The differences in morphology observed under fluorescent light compared with LED R:FR treatments indicate that light quality manipulation is a potential alternative to chemical growth regulators in controlled environments such as greenhouses and growth chambers.

Promotion of Flowering from Far-red Radiation Depends on the Photosynthetic Daily Light Integral

Under natural short days, growers can use photoperiodic lighting to promote flowering of long-day plants and inhibit flowering of short-day plants. Unlike traditional lamps used for photoperiodic lighting, low-intensity light-emitting diode (LED) lamps allow for a wide array of adjustable spectral distributions relevant to regulation of flowering, including red (R) and white (W) radiation with or without far-red (FR) radiation. Our objective was to quantify how day-extension (DE) photoperiodic lighting from two commercially available low-intensity LED lamps emitting R + W or R + W + FR radiation interacted with daily light integral (DLI) to influence stem elongation and flowering of several ornamental species. Long-day plants [petunia (Petunia ×hybrida Vilm.-Andr. ‘Dreams Midnight’) and snapdragon (Antirrhinum majus L. ‘Oh Snap Pink’)], short-day plants [african marigold (Tagetes erecta L. ‘Moonsong Deep Orange’) and potted sunflower (Helianthus annuus L. ‘Pacino Gold’)], and day-neutral plants [pansy (Viola ×wittrockiana Gams. ‘Matrix Yellow’) and zinnia (Zinnia elegans Jacq. ‘Magellan Cherry’)] were grown at 20/18 °C day/night air temperatures and under low (6–9 mol·m−2·d−1) or high (16–19 mol·m−2·d−1) seasonal photosynthetic DLIs from ambient solar radiation combined with supplemental high-pressure sodium lighting and DE LED lighting. Photoperiods consisted of a truncated 9-hour day (0800–1700 hr) with additional 1-hour (1700–1800 hr, 10 hours total), 4-hour (1700–2100 hr, 13 hours total), or 7-hour (1700–2400 hr, 16 hours total) R + W or R + W + FR LED lighting at 2 μmol·m−2·s−1. Days to visible bud, plant height at first open flower, and time to first open flower (TTF) of each species were influenced by DLI, lamp type, and photoperiod though to different magnitudes. For example, plant height of african marigold and potted sunflower at first open flower was greatest under R + W + FR lamps, high DLIs, and 16-hour photoperiods. Petunia grown under R + W lamps, high DLI, and 10- and 13-hour photoperiods were the most compact. For all species, TTF was generally reduced under high DLIs. For example, regardless of the lamp type, flowering of african marigold occurred fastest under a high DLI and 10-hour photoperiod. Flowering of petunia and snapdragon occurred fastest under a high DLI, R + W + FR lamps, and a 16-hour photoperiod. However, only under high DLIs, R + W or R + W + FR lamps were equally effective at promoting flowering when used to provide DE lighting. Our data suggest that under low DLIs, flowering of long-day plants (petunia and snapdragon) occurs more rapidly under lamps providing R + W + FR, whereas under high DLIs, flowering is promoted similarly under either R + W or R + W + FR lamps.

Stability of Lutein Content in Color Extracted from Marigold Flower and its Application in Candies

Stability of Lutein Content in Color Extracted from Marigold Flower and its Application in Candies

The effect of Marigold flower extracts on growth of Leishmania.

The effect of Marigold flower extracts on growth of Leishmania.

Stability lies in flowers: Plant diversification mediating shifts in arthropod food webs.

Arthropod community composition in agricultural landscapes is dependent on habitat characteristics, such as plant composition, landscape homogeneity and the presence of key resources, which are usually absent in monocultures. Manipulating agroecosystems through the insertion of in-field floral resources is a useful technique to reduce the deleterious effects of habitat simplification. Food web analysis can clarify how the community reacts to the presence of floral resources which favour ecosystem services such as biological control of pest species. Here, we reported quantitative and qualitative alterations in arthropod food web complexity due to the presence of floral resources from the Mexican marigold (Tagetes erecta L.) in a field scale lettuce community network. The presence of marigold flowers in the field successfully increased richness, body size, and the numerical and biomass abundance of natural enemies in the lettuce arthropod community, which affected the number of links, vulnerability, generality, omnivory rate and food chain length in the community, which are key factors for the stability of relationships between species. Our results reinforce the notion that diversification through insertion of floral resources may assist in preventing pest outbreaks in agroecosystems. This community approach to arthropod interactions in agricultural landscapes can be used in the future to predict the effect of different management practices in the food web to contribute with a more sustainable management of arthropod pest species.