Flower Heads Research Articles

Exploring the co-operativity of secretory structures for defense and pollination in flowering plants.

In flowers multiple secretory systems cooperate to deliver specialized metabolites to support specific roles in defence and pollination. The collective roles of cell types, enzymes, and transporters are discussed. The interplay between reproductive strategies and defense mechanisms in flowering plants has long been recognized, with trade-offs between investment in defense and reproduction predicted. Glandular trichomes and secretory cavities or ducts, which are epidermal and internal structures, play a pivotal role in the secretion, accumulation, and transport of specialized secondary metabolites, and contribute significantly to defense and pollination. Recent investigations have revealed an intricate connection between these two structures, whereby specialized volatile and non-volatile metabolites are exchanged, collectively shaping their respective ecological functions. However, a comprehensive understanding of this profound integration remains largely elusive. In this review, we explore the secretory systems and associated secondary metabolism primarily in Asteraceous species to propose potential shared mechanisms facilitating the directional translocation of these metabolites to diverse destinations. We summarize recent advances in our understanding of the cooperativity between epidermal and internal secretory structures in the biosynthesis, secretion, accumulation, and emission of terpenes, providing specific well-documented examples from pyrethrum (Tanacetum cinerariifolium). Pyrethrum is renowned for its natural pyrethrin insecticides, which accumulate in the flower head, and more recently, for emitting an aphid alarm pheromone. These examples highlight the diverse specializations of secondary metabolism in pyrethrum and raise intriguing questions regarding the regulation of production and translocation of these compounds within and between its various epidermal and internal secretory systems, spanning multiple tissues, to serve distinct ecological purposes. By discussing the cooperative nature of secretory structures in flowering plants, this review sheds light on the intricate mechanisms underlying the ecological roles of terpenes in defense and pollination.

Helichrysum arenarium as a source of flavonoids: Evaluation of antimicrobial activity and flavonoid content of extracts of Helichrysum flowers in vitro

Background: Helichrysum (family Asteraceae, kind of H. armenium, subfamily of Asteroideae) is known in Armenian traditional medicine for its diuretic, antioxidant, choleretic and anti-inflammatory properties. Studies have shown that Helichrysum flowers have a high content of flavonoids. In this study, we investigated the impact of various extraction process parameters on the yield of flavonoids obtained from Helichrysum flowers in Armenia. Subsequently, a comprehensive antimicrobial assay was conducted on the ethanol and aqueous extracts derived from the dried flower heads of Helichrysum. Objective: The objective of this study is to explore the influence of extraction process parameters on the yield of flavonoids from H. arenarium flowers and to determine their antibacterial activity.Methods: Antibacterial activity was determined using the agar-well diffusion method against four bacterial species (E. coli, Salmonella enterica, Staphylococcus aureus and S. typhimirium). The assessment of the total flavonoid content in the ethanol extract of Helichrysum was conducted using the AlCl3 method, following the procedure outlined by Andreeva and Kalinkina. Results: The ethanolic and aqueous extracts demonstrated antibacterial activity against Staphylococcus aureus ATCC 6538 and Bacillus Subtilis 168. However, no significant activity was observed against Escherichia coli ATCC 8739 and Salmonella Typhimurium ATCC 14028. The research findings affirm that the extract derived from everlasting flowers exhibits antimicrobial properties, particularly targeting Gram-positive bacteria. Conclusion: The results of our tests indicate that the extract of Helichrysum belonging to Armenian flora, is rich in flavonoids and has significant antimicrobial activity and may find application in the food industry, as well as in organic agriculture.Keywords: Helichrysum, plant extracts, flavonoids, antimicrobial activity, spectrophotometry

Sunflower (Heliánthus ánnuus) Yield and Yield Components for Various Agricultural Practices (Sowing Date, Seeding Rate, Fertilization) for Steppe and Dry Steppe Growing Conditions

The dynamics of the productivity of the sunflower hybrid “Baiterek 17” were studied for rainfed conditions of the steppe and dry steppe zones of Kazakhstan for two fertilizer levels (without fertilizers and with the application of a nitrogen-phosphorous fertilizer), two sowing dates, and three seeding rates. The growing season duration varied among zones and was affected by sowing dates. An increase in duration (3–5 days) was observed for the early sowing date and fertilized treatments, regardless of the zone. Increasing the seeding rate for all treatments by sowing date and fertilizer application reduced the duration of the growing season by 3–6 days. The fertilizer application did not affect the formation of seedlings in the study areas. In the dry steppe zone, from 2.5 to 4.8 plants/m2 were formed before harvesting, with an increase in the number of plants at the high seeding rate (57,000 seeds/ha). In the steppe zone, the same pattern was preserved: from 3.5 to 4.9 plants/m2 at a seeding rate of 65 thousand seeds/ha. The maximum diameter and weight of the flower head were found for the early sowing date and fertilized treatments at a low seeding rate, with a strong effect on the yield for both the steppe and dry steppe zones in 2022. On average, for both years, the highest yield for the dry steppe zone was obtained for the sowing date of 15 May and at a seeding rate of 57,000 seeds/ha, while for the steppe zone, the highest yield was obtained for the 10 May planting date and at a sowing rate of 65,000 seeds/ha. Improving plant nutrition and increasing the plant density up to a seeding rate of 65,000 seeds/ha for the early sowing dates (10 May) increased the plasticity in the steppe zone. For the dry steppe zone, the plasticity of the hybrid decreased, but the highest plasticity was also obtained for an earlier sowing date (15 May) and at a seeding rate of 57,000 seeds/ha crop. The study shows that the hybrid “Baiterek 17” has a high ecological plasticity under changing environmental conditions and, with an increase in moisture availability, it requires intensive agricultural practices (fertilization, increased seeding rate, and early sowing dates) to obtain a high yield.

New Insight into Enzyme Inhibitory and Anti-proliferative Activity of Echinops ritro L. (Asteraceae)

Echinops ritro L. is a perennial herbaceous plant in the tribe Cardueae, Asteraceae family, widely distributed, up to 1000 m a.s.l. In the present study, the enzyme inhibitory and anti-proliferative activity of E. ritro leaves and flowering heads extracts were assayed. Quantitative determination of 22 analytes, including eleven acylquinic and one hydroxycinnamic acids, and ten flavonoids was performed by Ultra high-performance liquid chromatography – diode array detector (UHPLC-DAD) analyses. The major compound was 1,5-dicaffeoylquinic acid, being presented at $$20.48\pm 0.22$$ µg/mg in the flowering heads, while the leaves demonstrated very high levels of chlorogenic acid ($$117.29\pm 14.20$$ µg/mg) and 3,5-dicaffeoylquinic acid ($$12.79\pm 0.282$$ µg/mg). The flavonoids were dominated by isoquercitrin and rutin ($$3.13\pm 0.033$$ and $$3.25\pm 0.057$$ µg/mg, respectively) together with metoxylated aglycones nepetin, hispidulin and jaceosidin (up to 0.51 µg/mg). The leaves extract revealed prominent acetylcholinesterase ($$2.33\pm 0.09$$ mg GALAE/g) and α-glucosidase inhibitory potential ($$0.37\pm 0.01$$ mmol ACAE/g). Nevertheless, the flowering heads extract showed distinct butyrylcholinesterase ($$1.41\pm0.35$$ mg GALAE/g), tyrosinase ($$45.66\pm0.84$$ mg KAE/g), amylase ($$0.37\pm0.02$$ mmol ACAE/g), and lipase ($$9.06\pm1.43$$ mg OE/g) inhibitory activity. The anti-proliferative assay was completed towards THP-1 monocyte leukemic cells, where at a concentration $$>1000$$ µg/mL, a significant dose dependent reduction of cell viability was observed for the leaves extract. In conclusion, the data revealed a new insight into the taxon for its health benefit application.

The Molecular Mechanism of Relatively Low-Temperature-Induced Broccoli Flower Bud Differentiation Revealed by Transcriptomic Profiling

Broccoli (Brassica oleracea L. var. italica) has a large, edible green flower head, which is one of its critical economic traits. A prerequisite of broccoli flower head formation is flower bud differentiation (FBD). Low-temperature treatment is an effective way to induce FBD in broccoli. However, the molecular mechanism underlying low-temperature-induced broccoli FBD remains largely unclear. In this study, using broccoli cultivar Zhongqing 10 as the experimental material, we investigated the effects of low-temperature treatment on FBD by comparing the plants grown at low temperatures (17 °C/9 °C, 16 h/8 h) with the control plants grown under normal temperature conditions (25 °C/17 °C, 16 h/8 h). After 15 days of different temperature treatments, the flower buds of the plants growing under the low-temperature condition started to differentiate. However, the control plants remained in the vegetative growth stage, indicating that low temperature successfully induced flower bud formation. Subsequently, a global transcriptomic analysis was conducted to detect the differentially expressed genes (DEGs) during low-temperature-induced FBD in broccoli. A total of 14 DEGs in five phytohormone signaling pathways, 42 DEGs in nine transcription factor families, and 16 DEGs associated with the floral development pathways were identified. More DEGs were present in the auxin signaling pathway than in other phytohormone signaling pathways, which indicated that the auxin signaling pathway played a critical role in modulating low-temperature-induced FBD in broccoli. Furthermore, four TF classes, including bZIP, GCM domain factors, MADS-box factors, and C2H2 zinc finger factors, possessed enriched motifs, indicating that their closely related DETFs ABI5, HY5L, WRKY11, WRKY15, WRKY22, SOC1, AGL8, FLC, SPL8, and SPL15 may be directly involved in the transcription regulation of broccoli FBD. This study provides an important basis for further investigation of the molecular regulatory mechanism of broccoli flower development under low temperatures.

Complex floral traits shape pollinator attraction to flowering plants in urban greenspaces

Urban greenspaces are recognized as a benefit to pollinator conservation. Selective planting of attractive flowering plants can improve the conservation value of urban greenspaces. However, the functional traits of flowering plants that moderate pollinator preference merits further study. We analyzed 98 ornamental plants and spontaneous plant species for ten categories of floral and plant traits across twelve parks or campus greenspaces in Wuhan, a megacity located in central China. Our results revealed that: (1) Plant species vary enormously in their pollinator visitation rate. (2) For Lepidoptera, the number of individuals to the plot was lower for disk/bowl-shaped flowers than other flower shapes, and it was negatively corelated with corolla tube length. The number of Diptera individuals to the plot was higher for white, red/pink and yellow/orange flowers than blue/violet flowers. (3) Honeybees preferred exotic annual/biennial herbaceous species, with disk/bowl and flag flowers. Solitary bees preferred horizontal, lip or flag flowers. Diptera most frequently visited upward-facing, yellow/orange flower heads and Lepidoptera preferred horizontal, funnel-shaped flowers or flower heads. Blue/violet flowers and a diverse floral orientation were preferred by most pollinator groups. We recommend planting native woody plants (Nandina domestica, Thymus quinquecostatus, Lagerstroemia indica, and Tamarix austromongolica) and attractive exotic plants (Centaurea cyanus, Borago officinalis, Portulaca grandiflora, and Echinacea purpurea) to support multiple pollinator groups. As preferences differ among pollinators, increasing the species richness of flowering plants is conducive to promote overall pollinator diversity.

Elevated temperatures shift flower head height distributions and seed dispersal patterns in two invasive thistle species.

Climate change may significantly alter how organisms disperse, with implications for population spread and species management. Wind-dispersed plants have emerged as a useful study system for investigating how climate change affects dispersal, although studies modeling wind dispersal often assume propagules are released from a single point on an individual. This simplifying assumption, while useful, may misestimate dispersal. Here, we investigate the effects of climate change on dispersal distances and spread rates, examining how these quantities shift when accounting for all points of seed release on an individual. Using the wind-dispersed invasive thistles Carduus nutans and Carduus acanthoides, we quantify temperature-driven shifts in the distribution of flower head heights using a passive warming field experiment, and estimate how these shifts affect dispersal using the Wald analytical long-distance (WALD) model; for C. nutans, we use existing demographic data to simulate how these shifts affect population spread rates. We also compare dispersal distances for both warmed and ambient temperature plants, considering the entire distribution of flower head heights versus the common assumption of point-source seed release at the maximum height. For experimentally grown individuals, an ~0.6°C higher growing temperature increased mean and maximum flower head height by 14.1 cm (15.0%) and 14.0 cm (13.2%), respectively, in C. nutans and by 21.2 cm (26.6%) and 31.8 cm (36.7%), respectively, in C. acanthoides. Seeds from warmed individuals were more likely to exceed a given dispersal distance than those from their unwarmed counterparts; warmed C. nutans and C. acanthoides seeds were on average 1.36 and 1.71 times as likely, respectively, to travel 10 m or more in dispersal simulations, with this disparity increasing at longer dispersal distances. For C. nutans, increased growing temperatures boosted simulated rates of population spread by 42.2%, while assuming dispersal from a maximum height point source rather than the true distribution of flower head heights increased simulated spread by up to 28.5%. Our results not only demonstrate faster population spread under increased temperatures, but also have substantial implications for modeling such spread, as the common simplifying assumption of dispersal from a single maximum height source may substantially overestimate spread rates.

Herbaceous Bee Forage Adaptation Trail in Lowlands of Borana Zone Southern Oromia

To mitigate the shortage of bee forage and help increase honey production, the use of cultivated perennial and annual nectar and pollen sources is highly important in beekeeping development. The study was conducted with the objective of evaluating and identifying adaptable honey bee forage species for beekeeping development. The planting materials were Aschynomene uniflorum, Miloletus alba, Fagopyrum esculentum, Sinaps alba, and Vicia sativa. The species were evaluated based on germination date, time to set flower, days to 50% flowering, number of flower heads per plant (at 50% flowering of the plant), flowering length (blooming duration), maturity date, and plant height at the flowering stage. Among the five evaluated herbaceous bee forage species, three of them, Aschynomene uniflorum, Fagopyrum esculentum, and Sinaps alba, are adapted and perform well in the most important agronomic parameters. Therefore, the selected bee forage species can be promoted, and beekeepers in the study areas and other areas with similar agroecology can utilise the forage species for beekeeping development. Moreover, evaluation of other agronomic parameters such as seeding rate, fertiliser rate, nectar and/or pollen yield, foraging intensity, and others over different locations of the Borana zone is recommended

Evaluating Various Colors of Persistent Luminescent Powders on Rose Cut Flowers

Rose cut flowers are popular in everyday bouquets or for special occasions, and tinting of the flowers by means of color addition increases the flowers economical value and aesthetic appeal. This study evaluated red and white luminescent rose cut flowers, which was achieved by applying six persistent luminescent powders. Solutions of each color were prepared by mixing 6 g of powder and 240 ml of deionized water and sprayed four times around the flower head plus a control. Images were taken of the flowers before ultraviolet blacklight exposure and after exposure to be later analyzed with ImageJ software. Daily measurements were taken including vase weight, average floral diameter, and visual deterioration based on scale of 1 to 4. Overall measurements included mean brightness; red, green, and blue measured values; dominant wavelengths of emitted color; flower diameter change rate; relative water percent; solution uptake rate; and vase solution uptake rate. For luminescent brightness mean without ultraviolet, white rose with blue powder had the greatest value. For luminescent brightness after ultraviolet exposure, white rose with green powder had the greatest value. With ultraviolet exposure, white roses with green powder had the greatest value followed by blue, orange, and white. Red powder on white and red roses experienced little to no luminescence before or after ultraviolet exposure. Mean and mode varied in their calculated dominant wavelengths; therefore, it is recommended to use mean values because more similarities in matching of the powder color and the calculated dominant wavelength were reported. Ultimately, white roses are preferred because they seemed to have greater health and luminescence compared with red roses, and green and blue powder would be recommended for luminescent application for brightness.

Assessing effective mechanical and chemical strategies for managing Eucosma giganteana (Lepidoptera: Tortricidae) in the perennial oilseed crop, Silphium integrifolium (Asteraceae: Heliantheae).

Eucosma giganteana (Riley) is a native specialist pest of silflower, Silphium integrifolium Michx., which is currently being domesticated as a perennial oilseeds crop. The larvae of this moth attack silflower capitula and root crowns, causing both seed damage and long-term degradation of plants. To determine methods to manage E. giganteana in silflower crop fields, we conducted a laboratory bioassay and 3 field experiments to assess the effects of a suite of organic, conventional, and mechanical treatments on E. giganteana mortality and colonization of flower heads. Pyrethroids (permethrin, cyfluthrin), chlorantraniliprole, and methoxyfenozide each had significant insecticidal effects on E. giganteana in at least 2 of the experiments conducted. Nematodes marginally increased larva mortality in the laboratory bioassay and could be further investigated as a soil-applied biological control. In 2 separate field experiments, trimming the top 15% of silflower plants to delay flowering did not alone reduce E. giganteana colonization of flower heads throughout the growing season. However, when trimming was paired with a single chlorantraniliprole application, colonization of capitula was reduced by 83% over untreated control plants. Collectively, these experiments provide evidence for several treatments that could be further tested and incorporated into an integrated pest management strategy for E. giganteana.

Morphological Characteristics and Expression Patterns of CmCYC2c of Different Flower Shapes in Chrysanthemum morifolium

The chrysanthemum is widely used as a cut flower, potted flower, and garden flower worldwide and has high ornamental, edible, and medicinal value. The flower heads, composed of ray florets and disc florets, are the most diverse in terms of morphology among ornamental plants. Here, we compared and analyzed the developmental processes of different capitulum types as well as ray florets and disc florets. Morphological differentiation of the two florets occurred on the dorsal domain of the petals at stage Ⅳ of flower development, and differences in stamen development occurred at stage Ⅴ. The dorsal domain of the ray florets and the early stage of flower development were also an essential site and period, respectively, for the differences among capitulum types. In situ hybridization revealed that CmCYC2c, whose homologs are involved in the specification of floret identity in Asteraceae, was expressed in both the dorsal and ventral domains of the ray petals in the tubular-type chrysanthemum, whereas, it was differentially transcribed in the ray petals of flat- and spoon-type chrysanthemum cultivars and had lower or no expression in the dorsal domain and higher expression in the ventral domain at stage Ⅳ. Our study indicates that the expression pattern of CmCYC2c on the dorsal domain of the ray floret at stage Ⅳ contributes to the formation of diverse flower head types in chrysanthemums.

EFFECT OF ASCORBIC ACID AND CALCIUM FOLIAR APPLICATION ON GROWTH, YIELD AND MARKETABILITY OF BROCCOLI

The experiments were carried out at the College of Agricultural Engineering Sciences - University of Baghdad during the fall season of 2021-2020 to study the effect of foliar application of ascorbic acid (0, 25, 50, 75 mg. L-1) which were symbolized as A0, A1, A2, and A3, and chelated calcium (0, 1.0, 1.5, 2.0 g. L-1) which were symbolized as Ca0, Ca1, Ca2, and Ca3 on the growth, yield and marketability of broccoli. A factorial experiment was carried out within the RCBD design, in a total of 16 treatments with three replicates. The main flowering heads were kept at temperatures 6-8° C for 20 days and 18-25° C for 4 days. The results were revealed that the individual and interaction treatments were recorded a significant values among the studied parameters, and the interaction treatment of A3Ca3 achieved the most significant increment of leaves area, total yield, heads weight, heads diameter, calcium content in leaves and heads, the chlorophyll and vitamin C content in the heads, 1962.54dm2.plant-1, 55.10 ton.ha-1, 889.78 g.head-1, 21.84 cm, 1.85% in leave, 1.68%, 152.35 mg.100g-1 and 305.07 mg.100g-1 respectively decreased weight loss, increased total soluble solids, and maintained chlorophyll and vitamin C in the flowering heads after storage reached 11.40%, 134.72 and 96.41 mg.100g-1, 136.40 and 130.53 mg.100g-1 respectively at two temperatures.

In vitro antioxidant, anti-inflammatory activities and acetylcholinesterase inhibition properties of selected plant extracts

Plant extracts remain an infinite source of bioactive chemicals and an inexhaustible resource for discovering new drugs of natural origin. Thus, in this study, we focused on analysing 29 ethanolic extracts (E1-E29) from selected plants of flora of Poland to assess their antioxidant, anti-inflammatory and acetylcholinesterase inhibitory properties in relation to the chemical profiles of phenolic compounds. The results show that the investigated samples differed in terms of their chemical compositions and biological activities. The extract from Cirsium palustre leaves (E13) possesses the highest phenolic and flavonoid contents as well as antiradical activity in the DPPH (2,2-diphenyl-1-picrylhydrazyl) test (415.28 ± 2.22 µM of Trolox equivalent). On the other hand, the most potent anti-inflammatory agents (at 125 µg/mL) were extracts from Odontites vulgaris herbs (E24), with a COX-2 (cyclooxygenase-2) inhibition percentage of 74.54 ± 0.77, and Erigeron acris flower heads (E22), with a 15-sLOX (soybean 15-lipooxygenase) inhibition percentage of 42.45 ± 3.32. All extracts exhibited moderate acetylcholinesterase inhibitory activity. Moreover, to the best of our knowledge, the present study is the first to report phytochemical and pharmacological analyses of extracts from Anthericum ramosum and Lysimachia europaea.

Influence of Biochar on Growth, Yield and Quality of Broccoli

Broccoli is one of the most important, nutrient-rich vegetables among cole crops which belong to the family Brassicaceae. It is known to be a healthy and delectable vegetable which is rich in many nutrients. Biochar is considered as a potential substitute for soil organic matter (SOM). Biochar addition to low organic carbon soils can act as a feasible solution to keep soil biologically active for the cycling of different nutrients. The application of biochar could improve soil fertility, increase crop yield, enhance plant growth and microbialabundance, and immobilize different contaminants in the soil. Due to thelarge surface area of biochar, which generally depends upon the types of feedstock and pyrolysis conditions, it helps to reduce the leaching of fertilizers from the soil and supplies additional nutrientsto growing crops. In view of the above importance all possible issues related to biochar application should beconsidered. Previous literature review shows that applying biochar to the broccoli plant improved only the leaf area and root length with significant changes. The highest yield per plot (4.49 kg), bud weight (499.37g), bud diameter (16.55 cm), and yield per hectare (14.98 t ha-1) of broccoli was found to be significant in biochar treated plot (T2: PSB 100 L/ha + Biochar 30 t ha-1). Considering classification of the flowering heads by categories, M (manure pellet) + EB (enriched-biochar amended soil and organic fertilizer) + AND (manure pellet and enriched-biochar amended soil treated with organic fertilization) treatments showed a higher number of first category flowering heads with regard to other treatments. Therefore, the use of biochar is an effective approach for potential nutrient reservoir for plants and a good amendment to improve soil properties.

Habitat fragmentation decouples fire-stimulated flowering from plant reproductive fitness

Many plant species in historically fire-dependent ecosystems exhibit fire-stimulated flowering. While greater reproductive effort after fire is expected to result in increased reproductive outcomes, seed production often depends on pollination, the spatial distribution of prospective mates, and the timing of their reproductive activity. Fire-stimulated flowering may thus have limited fitness benefits in small, isolated populations where mating opportunities are restricted and pollination rates are low. We conducted a 6-y study of 6,357 Echinacea angustifolia (Asteraceae) individuals across 35 remnant prairies in Minnesota (USA) to experimentally evaluate how fire effects on multiple components of reproduction vary with population size in a common species. Fire increased annual reproductive effort across populations, doubling the proportion of plants in flower and increasing the number of flower heads 65% per plant. In contrast, fire's influence on reproductive outcomes differed between large and small populations, reflecting the density-dependent effects of fire on spatiotemporal mating potential and pollination. In populations with fewer than 20 individuals, fire did not consistently increase pollination or annual seed production. Above this threshold, fire increased mating potential, leading to a 24% increase in seed set and a 71% increase in annual seed production. Our findings suggest that density-dependent effects of fire on pollination largely determine plant reproductive outcomes and could influence population dynamics across fire-dependent systems. Failure to account for the density-dependent effects of fire on seed production may lead us to overestimate the beneficial effects of fire on plant demography and the capacity of fire to maintain plant diversity, especially in fragmented habitats.

Chemodiversity in flowers of Tanacetum vulgare has consequences on a florivorous beetle.

The chemical composition of plant individuals can vary, leading to high intraspecific chemodiversity. Diversity of floral chemistry may impact the responses of flower-feeding insects. Tanacetum vulgare plants vary significantly in their leaf terpenoid composition, forming distinct chemotypes. We investigated the composition of terpenoids and nutrients of flower heads and pollen in plants belonging to three chemotypes - dominated either by β-thujone (BThu), artemisia ketone (Keto) or a mixture of (Z)-myroxide, santolina triene, and artemisyl acetate (Myrox) - using different analytical platforms. We tested the effects of these differences on preferences, weight gain and performance of adults of the shining flower beetle, Olibrus aeneus. The terpenoid composition and diversity of flower heads and pollen significantly differed among individuals belonging to the above chemotypes, while total concentrations of pollen terpenoids, sugars, amino acids, and lipids did not differ. Beetles preferred BThu over the Myrox chemotype in both olfactory and contact choice assays, while the Keto chemotype was marginally repellent according to olfactory assays. The beetles gained the least weight within 48 h and their initial mortality was highest when feeding exclusively on floral tissues of the Myrox chemotype. Short-term weight gain and long-term performance were highest when feeding on the BThu chemotype. In conclusion, the beetles showed chemotype-specific responses towards different T.vulgare chemotypes, which may be attributed to the terpenoid composition in flower heads and pollen rather than to differences in nutrient profiles. Both richness and overall diversity are important factors when determining chemodiversity of individual plants and their consequences on interacting insects.

Development of a Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Method for Characterizing Linalool Oral Pharmacokinetics in Humans.

Lavender (Lavandula angustifolia Miller or Lavandula officinalis Chaix) is an ethnopharmacological plant commonly known as English lavender. Linalool and linalyl acetate are putative phytoactives in lavender essential oil (LEO) derived from the flower heads. LEO has been used in aroma or massage therapy to reduce sleep disturbance and to mitigate anxiety. Recently, an oral LEO formulation was administered in human clinical trials designed to ascertain its anxiolytic effect. However, human pharmacokinetics and an LC-MS/MS method for the measurement of linalool are lacking. To address this deficiency, a rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the analysis of linalool in human serum. Prior to the analysis, a simple sample preparation protocol including protein precipitation and liquid-liquid extraction of serum samples was created. The prepared samples were analyzed using a C18 reversed-phase column and gradient elution (acetonitrile and water, both containing 0.1% formic acid). A Waters Xevo TQ-S tandem mass spectrometer (positive mode) was used to quantitatively determine linalool and IS according to transitions of m/z 137.1→95.1 (tR 0.79 min) and 205.2→149.1 (tR 1.56 min), respectively. The method was validated for precision, accuracy, selectivity, linearity, sensitivity, matrix effects, and stability, and it was successfully applied to characterize the oral pharmacokinetics of linalool in humans. The newly developed LC-MS/MS-based method and its application in clinical trial serum samples are essential for the characterization of potential pharmacokinetic and pharmacodynamic interactions.

Flower yield potential of Pyrethrum (<em>Chrysanthemum cinerariaefolium</em> L.) under various NPK Levels in the Lower Hills of Uttarakhand, India

Purpose: A favorable environment is available for the cultivation of Pyrethrum in the hilly regions of India, as well as in some mountainous areas of India. In view of the demand for Pyrethrin, it is very necessary to promote the huge cultivation of Pyrethrum. There is no misconception that research work has not been done to promote Pyrethrum, but the data related to the assessment of the right amount of nutrients required for the crop is not available in research related to agrotechnology. If the crop is to be taken as a ratoon crop, then it is very important to estimate the amount of nutrients for single recommendation of crop cultivation. Research Method: A research experiment was conducted in the year 2021 at the CSIR-Central Institute of Medicinal and Aromatic Plant Research, Centre Purara, Bageshwar (Uttarakhand) to study the flower yield potential of Pyrethrum under various NPK levels in the lower hills of Uttarakhand. The experiment was carried out in Complete Randomized Block Design. The six different levels of NPK (kg ha-1) were taken as treatments, i.e., control, 60:60:20, 80:70:30, 100:80:40, 120:90:50, and 150:100:60. Various plant growth and yield parameters considered in the study include plant height (cm), plant diameter (cm), number of flower heads, fresh flower weight plant-1 (g), dry flower weight plant-1(g), fresh flower yield (kg ha-1), dry flower yield (kg ha-1), Pyrethrin concentration (%) and yield (kg ha-1). Findings: Based on the research findings, it seems that the NPK level of 120:90:50 is the best combination to obtain the highest dry flower yield (310.49 kg ha-1) in the lower hills of Uttarakhand. However, the fresh flower weight obtained was the highest under the NPK level of 100:80:40 i.e., 840.47 kg ha-1, but it’s dry flower yield estimated was 301.93 kg ha-1 which was the second highest yield after 310.49 kg ha-1. This could be due to the difference in moisture levels in fresh flowers at the time of harvesting.Research Limitation: Considering the climate of the hilly regions of Uttarakhand, not much work has been done to assess and standardize the proper amount of nutrients required for Pyrethrum crop cultivation, which needs to be done.Originality/ Value: In the hilly areas of Uttarakhand, farmers are interested in the cultivation of Pyrethrum, but if farmers will adopt this crop cultivation as a ratoon crop, then in such a situation it is absolutely necessary to assess the proper amount of nutrients. This research will prove helpful in promoting the cultivation of Pyrethrum in the hilly areas of Uttarakhand.

Assessment of Shelf life of Chrysanthemum (Dendranthema x grandiflora Tzelev.) var. Marigold Flowers as Influenced by Phenophase Based Irrigation and Nutrition Schedule

The present investigation was conducted in the Division of Flower and Medicinal Crops at the ICAR-Indian Institute of Horticultural Research, Bengaluru, to evaluate the influence of phenophase based irrigation and fertigation schedules on shelf life of chrysanthemum (Dendranthema x grandiflora Tzelev.) var. Marigold. The experiment comprised of three main plots (irrigation regimes) and five sub plots (nutrient regimes) and was laid out in split plot design with three replications. Irrigation regime at 0.8, 1.0 and 1.2 ER at vegetative, bud and flowering phases, respectively along with weekly fertigation of NPK @ 75:112.5:75 kg /ha (75% RDF) in three split doses of 40:20:20 % NPK during vegetative phase, 30:40:40 % NPK during bud phase and 30:40:40% NPK during flowering phase, recorded the maximum shelf life of flowers (12.15 days) whereas, the minimum shelf life (7.60 days) was observed in the irrigation regime at 0.6,0.8 and 1.0 ER at vegetative, bud and flowering phases, respectively along with conventional method soil application of recommended dose of fertilizer (100:150:100 Kg NPK/ha).The shelf life of flowers had significantly high positive association with the physiological parameters of the plant viz., relative water content (0.728), transpiration rate (0.201), single flower weight (0.559) and stomatal conductance rate (0.492). Whereas, the photosynthetic rate (0.214), diameter of the flower head (0.269) and estimated flower yield (0.047) were significantly and positively correlated with shelf life of flowers. However, the days taken for bud appearance (-0.250) was negatively associated with shelf life of flowers.

Pyrethrins Profiles and Contents in Seedlings, in Vitro Cultures, and Acclimatized Plants of Tanacetum cinerariifolium Clones (Asteraceae)

Tanacetum cinerariifolium (Trevir.) Sch. Bip., Asteraceae, known as pyrethrum, is a perennial herb endemic to the eastern Adriatic coast. It is cultivated worldwide for its valuable secondary metabolites: pyrethrins, which are natural insecticides. Pyrethrins are monoterpene esters of chrysanthemum acid (Pyrethrin-I, Cinerin-I, Jasmolin-I) or pyrethric acid (Pyrethrin-II, Cinerin-II, Jasmolin-II) with lethal or knock-down insecticidal properties, respectively. The market demand of pyrethrin-based products is increasing due to the organic farming requirements. In the present study the content of pyrethrins was determined by GC/MS in n-hexane extracts of shoots of several in vitro clones and in flower heads of outdoor acclimatized plants from the same clones during primary and secondary blooming, as well as in seedlings grown on different soil types. Statistical analyses were done by One-way ANOVA Post Hoc LSD analysis. All pyrethrins were detected in all samples, including a Pyrethrin-I isomer but they differed in content and proportion. As expected, pyrethrins in in vitro shoots and in seedlings were in small amounts. However, in the flower heads of the acclimatized plants, pyrethrin content was comparable to that of the native Dalmatian populations. The main component in all samples was Pyrethrin-I, possessing the strongest insecticidal activity, with the highest content in the flower heads of the primary flowering: 4.87 mg/g with a CV of 24.9%. Statistical differences were noted between clones for Pyrethrin-II and the Pyrethrin-I isomer in June samples, and Pyrethrin-I in September samples (p < 0.05). A wide range of variation was also found in seedlings due to different soil types. Growing conditions should be optimized in terms of sunlight and watering, and further research on pyrethrin content should be carried out in several consecutive years.