Flower Heads Research Articles

Lanceolanone A, a new biflavanone, and a chalcone glucoside from the flower heads of Coreopsis lanceolata and their aldose reductase inhibitory activity and AMPK activation.

The MeOH extract of the flower heads of Coreopsis lanceolata L. (Asteraceae) exhibited aldose reductase (AR) inhibitory activity (IC50 8.36µg/mL). Bioassay-guided fractionation of the extract resulted in the isolation of a new biflavanone-named Lanceolanone A (1) and a chalcone glucoside (6), along with 12 known compounds (2-5 and 7-14), of which 4, 7, 9, 10, and 12 were isolated from C. lanceolata for the first time. The structures of the new compounds (1 and 6) were determined by extensive spectroscopic analysis, including two-dimensional (2D) NMR, and ECD calculation method. Compounds 2, 4, 11, 13, and 14 exhibited AR inhibitory activities with IC50 values between 2.40 and 9.99µM. Furthermore, 8-13 at 1.0mM activated AMPK expression in HepG2 human hepatoma cells compared to the control.

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Water consumption of agricultural plants can be considered one of the main elements of the assessment needed for irrigation. Covering water needs during the growing season is done by applying irrigation. Quantitative studies on evapotranspiration performed on maize and sunflower crops showed different values. The average water consumption calculated according to the Thornthwaite method recorded the highest values in June, July and August. For the maize crop, the highest water consumption was reached in July (1480 m3 / ha or 27.1% of the total consumption), during which time the pollination, the growth of the cobs and the formation of the grain take place. In sunflower cultivation, the highest consumption was recorded in July (1302 m3 / ha or 28.2% of total consumption) and correspond to the phases of growth of the flowering head (inflorescence) and seed formation. The purpose of this paper is to establish the need for hydro-amelioration arrangements through a correct irrigation regime during the growing season following the results obtained based on water consumption in the crops studied. The present paper presents the results of water consumption in maize and sunflower crops, calculated according to the Thornthwaite method, as well as the correction coefficients for potential evapotranspiration conditions on the upper Prut river basin.

Enriched-biochar application increases broccoli nutritional and phytochemical content without detrimental effect on yield.

Soil fertility is a major concern during vegetable production. Conventional versus organic fertilization has been studied in order to conserve soil properties. While some reports point out an increase in food nutritional properties, the loss of crop yield under organic conditions continues to be a problem. Thus, an experiment with broccoli in the field was carried out, comparing crop management under conventional fertilization (CF) and two soil amendment treatments: manure pellet (M) and an enriched-biochar (EB) supplemented by an organic fertilizer (AND) applied alone (M+CF; EB+AND) or in combination (M+EB+AND). Crop yield and the nutritional properties in the flowering heads (mineral content, phenolic compounds and glucosinolates (GSLs)), were determined. Enriched-biochar and manure as a standalone amendment resulted in higher crop yield regarding CF, but not when they were applied in combination. The number of flowering heads with no-commercial characteristics was lower after enriched-biochar soil application. Finally, enriched-biochar treatment enhanced NO3 - , PO4 3- and SO4 2- levels in the flowering heads, and some of the ion contents can be associated with mineral changes in the soil after the biochar amendment. Also, the contents of phenolic compounds and indole GSLs were higher after enriched-biochar application compared with the other treatments, GSL increase being due to the higher percentage of sulfur in the plant rather that an adequate N/S ratio. Application of enriched-biochar amendment in the cultivation of broccoli is appropriate, since there are no losses of yield and an increase in nutritional compounds in the flowering heads. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A blend of Sphaeranthus indicus flower head and Terminalia chebula fruit extracts reduces fatty liver and improves liver function in non-alcoholic, overweight adults

Background: Excessive accumulation of fat in the liver is a common clinical presentation in non-alcoholic fatty liver disease (NAFLD). The increasing prevalence of NAFLD is a growing health problem worldwide. The major risk factors of NAFLD include obesity, hyperlipidemia, and insulin resistance.Objective: The aim of the present randomized, double-blind, placebo-controlled clinical trial was to assess the efficacy and tolerability of an herbal composition CL16049F1 in reducing fatty liver conditions and improving liver function in non-alcoholic, overweight individuals. CL16049F1 is a proprietary blend of Sphaeranthus indicus flower head and Terminalia chebula fruit extracts.Materials and Methods: Ninety male and female subjects (age: 25-60 yrs., BMI: 23-29 kg/m2) with elevated Fatty Liver Index (FLI) between 31 and 59 were randomized into three groups (n=30). The participants received a daily dose of 300mg CL16049F1, 320 mg Silymarin, or a placebo over a period of 84 consecutive days. FLI was evaluated as the primary efficacy measure. The secondary efficacy measures included the liver enzymes, lipid profile, and oxidative stress markers in serum, A 36-Item Short-Form Health Survey (SF-36), and Gastrointestinal symptoms (GIS) score were also evaluated. The clinical biochemistry, hematology, urine, and vital signs were evaluated as safety measures. Adverse events were also monitored.Results: Eighty-eight subjects completed the study. Post-trial, the FLI score of CL16049F1-supplemented subjects was reduced by 13.81% (p<0.05) and 16.08% (p<0.05), while the Silymarin supplemented group exhibited reductions of 7.50% (p<0.05) and 7.27% (p<0.05) as compared to baseline and placebo, respectively. CL16049F1 supplementation significantly improved the liver enzymes, lipid profile, and oxidative markers in serum. The changes in the secondary efficacy measures in these treatment groups are comparable. No major adverse events were observed.Conclusion: CL16049F1 is a well-tolerated and effective herbal formulation to reduce fatty liver and improve liver function in non-alcoholic, overweight subjects.Keywords: Non-alcoholic fatty liver disease, Fatty liver index, CL16049F1, hepatoprotective botanical formulation.

Anti-Diabetic and Antioxidant Effects of Methanolic Flower Head Extract of Tagetes Patula in Streptozotocin and Dexamethasone Induced Diabetic Rats


 Diabetes is a chronic metabolic disorder characterized by a high blood glucose concentration, i.e., hyperglycemia or caused by insulin deficiency, often combined with insulin resistance. In the Present study, the antidiabetic and antioxidant activity of the methanolic extract of Tagetes patula flower heads was screened out in rodent models. The pharmacological evaluation was carried out using 200 and 400 mg/kg, b.w. The in-vivo antidiabetic activity was performed in streptozotocin, dexamethasone- induced diabetic models and oral glucose tolerance test. Metformin hydrochloride was used as a standard. The parameters like blood glucose levels, insulin levels, homeostasis assessment of insulin resistance, insulin sensitivity, and fasting glucose-insulin ratio were estimated in these models. The in-vitro antioxidant activity of methanolic extract of Tagetes patula was performed by using hydroxyl radical scavenging assay and Ascorbic acid was used as a standard. The preliminary phytochemical screening of Tagetes patula revealed the presence of phytoconstituents like alkaloids, flavonoids, saponins, steroids, phenols, carbohydrates, triterpenoids, and tannins. The extract showed a significant decrease in the elevated blood glucose levels in streptozotocin, dexamethasone-induced diabetic models, and also in the oral glucose tolerance test. The extract prevented insulin resistance and significantly increased insulin sensitivity in the dexamethasone-induced model. The various phytochemical constituents like alkaloids, flavonoids, saponins, steroids, and phenols might be responsible for lowering the blood glucose levels in the animal models mentioned above. The extract showed significant scavenging activity against hydroxyl free radicals. From the above outcomes, it is flawless that the methanolic extract of Tagetes patula has antidiabetic and antioxidant activities.

GC/MS Based Metabolite Profiling and Biological Activity of Leaves and Flower Heads of Tanacetum Cinerariifolium (Trevir.) Sch.Bip.

Abstract Flower heads and leaves of Tanacetum cinerariifolium (Trevir.) Sch. Bip. were examined separately for bioactive compounds and biological activity. The compounds were identified by GC/MS analysis. Studied extracts were evaluated for free radical scavenging activity, and for inhibition of acetylcholinesterase and seed germination. Free phenolic acids and flavonoid aglycones were found in larger quantities in the leaves than in the flower heads, where sterols, fatty acids, pyrethrins, sugars, sugar derivatives and bound phenolic acids predominated. Significant antiradical activity (IC50 /mL) and low acetylcholinesterase inhibitory activity (IC50 >1 mg/mL) was found. Moderate inhibitory activity against germination and root elongation of Lolium perenne L. seeds was determined. The study presents for the first time detailed data on the content of phenolic acids in free, esterified and insoluble-bound forms in this species. Some of the identified flavonoids from the leaf extract are reported for the first time in the species. Keywords: GC/MS, Flavonoids, Phenolic acids, Asteraceae (Composite)

Influence of nitrogen level and plant density on growth parameters and economic efficiency of sunflower cultured in Thua Thien Hue province

Sunflower (Helianthus annuus) cultivation is gaining popularity among Vietnamese farmers. Two separate experiments were conducted from January to April 2018 in a randomized complete block design with three replicates. Four levels of each factor were included in the experiments: 0, 20, 40, and 60 kg/ha for nitrogen and 11, 13, 16, and 20 plants/m2 for the density. The nitrogen fertilizer (up to 60 kg/ha) substantially affects the leaf area, diameters of stem plant, receptacle and flower head, and cut flower vase life. Low plant density works well on plant height, leaf number, width and length at the flowering stage, with the largest head diameter (17.2 cm) at the 13 plants/m2 density. Based on the results of both growth ability and economic efficiency, we suggested applying N at 60 kg/ha and planting at 16 plants/m2 density for growing F1 cut sunflowers in Thua Thien Hue province.

Arnica Montana L. Supercritical Extraction Optimization for Antibiotic and Anticancer Activity.

Arnica montana L. flower heads are known for their antioxidant, antimicrobial, and anticancer activity. The aim of this work was to optimize the process of supercritical CO2 extraction, to achieve high extraction yield and high content of biologically active components, and to confirm the antimicrobial and anticancer activity of the extract. The influence of pressure and temperature on the total phenolic content, antioxidant activity, and proanthocyanidin content was evaluated. The pressure and temperature were found to be interdependent. A temperature of 60°C and a pressure of 30 MPa resulted in a high extraction yield, antioxidant activity and phenolic content. The content of proanthocyanidins was highest at a pressure between 18 and 24 MPa. The extracts inhibited three different microorganisms successfully; Staphylococcus aureus, Escherichia coli and Candida albicans, at concentrations ranging from 0.1 to 5.16 mg/ml and showed anticancer activity decrease up to 85% at a concentration of 0.5 mg/ml.

Dissecting weed adaptation: Fitness and trait correlations in herbicide-resistant Alopecurus myosuroides.

BACKGROUNDUnravelling the genetic architecture of non‐target‐site resistance (NTSR) traits in weed populations can inform questions about the inheritance, trade‐offs and fitness costs associated with these traits. Classical quantitative genetics approaches allow study of the genetic architecture of polygenic traits even where the genetic basis of adaptation remains unknown. These approaches have the potential to overcome some of the limitations of previous studies into the genetics and fitness of NTSR.RESULTSUsing a quantitative genetic analysis of 400 pedigreed Alopecurus myosuroides seed families from nine field‐collected populations, we found strong heritability for resistance to the acetolactate synthase and acetyl CoA carboxylase inhibitors (h 2 = 0.731 and 0.938, respectively), and evidence for shared additive genetic variance for resistance to these two different herbicide modes of action, r g = 0.34 (survival), 0.38 (biomass). We find no evidence for genetic correlations between life‐history traits and herbicide resistance, indicating that resistance to these two modes of action is not associated with large fitness costs in blackgrass. We do, however, demonstrate that phenotypic variation in plant flowering characteristics is heritable, h 2 = 0.213 (flower height), 0.529 (flower head number), 0.449 (time to flowering) and 0.372 (time to seed shed), demonstrating the potential for adaptation to other nonchemical management practices (e.g. mowing of flowering heads) now being adopted for blackgrass control.CONCLUSIONThese results highlight that quantitative genetics can provide important insight into the inheritance and genetic architecture of NTSR, and can be used alongside emerging molecular techniques to better understand the evolutionary and fitness landscape of herbicide resistance. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Spatially discrete disturbance processes enhance grassland floral resources

Abstract Grasslands provide essential floral resources for both managed and wild pollinators. However, grassland flowers in remaining native landscapes are threatened due to non‐native plant invasions and alterations to historic disturbance regimes such as fire and grazing. The potential for managed disturbance to promote grassland floral resources remains unclear. Fire and grazing historically occurred interactively, but uniform application of each may be a detriment to floral resources and the pollinators depending on them. Though fire can increase resources available to plants and stimulate flowering, it initially destroys floral resources and may delay flower availability. Similarly, grazing removes competitors of flowering plants, but destroys flower heads. To address this knowledge gap, we investigated the impacts of rotational fire and cattle grazing (patch‐burn grazing with one and two seasons of fire per year) versus traditional season‐long grazing with no fire on floral resources in mixed‐grass prairie. In patch‐burn treatments, part of each pasture is burned each year, which focuses grazing activity due to the high‐quality regrowth. We aimed to use fire to remove litter around flowering plants while also sheltering established flower heads from grazing pressure by directing cattle away from regenerating forbs in unburned portions of the landscape. Over two summers, we performed weekly flower surveys in season‐long grazing and patch‐burn grazing pastures. We analysed total seasonal floral resources, maximum floral abundance and seasonal species richness between treatments. Over 2 years, we surveyed 1,238,241 ramets of 160 species, focusing on 36 common species for individual analysis. We found broad positive associations between patch‐burn grazing and total seasonal flower abundance, maximum flower abundance and species richness compared to traditional management. In most cases, patch‐burn grazing with dormant and growing season fires produced higher floral abundance, total seasonal floral resources and species richness than patch‐burning with dormant season fires alone, suggesting benefits of increased levels of pyrodiversity. Synthesis and applications. Under increasing pressure to manage for declining pollinators, rangeland managers must consider strategies to enhance floral resources within the context of livestock production goals. The spatiotemporal interaction of cattle grazing and fire shows promise for promoting floral resource abundance and diversity.

Dynamic regulation of volatile terpenoid production and emission from Chrysanthemum morifolium capitula

Flower-associated communities consist of both mutualistic and antagonistic organisms. We have limited knowledge on how flowers regulate volatiles to balance their defense against antagonists and the attraction of beneficial organisms necessary for reproductive success. Asteraceae is the largest family among flowering plants. Its representatives are characterized by unique inflorescence called capitulum, which has been reduced to a reproduction unit resembling a single flower. Here, we chose Chrysanthemum morifolium, a model species of Asteraceae, to investigate how the capitulum balances the accumulation and emission of floral terpenoid volatiles that are implicated in defense and pollinator attraction, respectively. Our results showed that the capitula of C. morifolium produce and emit complex mixtures of monoterpenoids and sesquiterpenoids. The highest concentrations of terpenoids were detected in the bud stage of the capitula. In contrast, the capitulum reached the highest emission level prior to full blooming. The disc florets were the dominant organs of terpenoid accumulation and emission in the full-openness stage. To understand the molecular basis of volatile terpenoid biosynthesis in C. morifolium, experiments were designed to study terpene synthase (TPS) genes, which are pivotal for terpene biosynthesis. Eight CmCJTPS genes were identified in the transcriptomes of C. morifolium, and the proteins encoded by five genes were found to be biochemically functional. CmCJTPS5 and CmCJTPS8 were the multi-product enzymes catalyzing the monoterpenoid and sesquiterpenoid formation, which closely matched the major terpenoids produced in the flower heads. The five functional terpene synthase genes exhibited similar temporal expression patterns but diverse spatial expression levels, suggesting tissue-specific functions. Altogether, our results illustrate the dynamic patterns of accumulation and emission of floral volatile terpenoids implicated in defense and attracting pollinators in C. morifolium, for which both the regulation of TPS gene expression and the regulation of release may play critical roles.

Floral biology, floral volatile organic compounds and floral visitors of Chromolaena odorata, an invasive alien species in West Bengal, India

Abstract. Layek U, Das A, Das U. 2022. Floral biology, floral volatile organic compounds and floral visitors of Chromolaena odorata, an invasive alien species in West Bengal, India. Biodiversitas 23: 2118-2129. Chromolaena odorata (L.) R.M. King & H. Rob. is a fast-growing weed native to the Neotropics and introduced in several regions of Africa, the Pacific Islands, and Southeast Asia, including West Bengal in India. It is one of the world’s most widespread and troublesome invasive alien plant species (IAPS) that severely infest natural habitats and crop fields. However, extensive data documents about the reproductive ecology are unknown, especially within West Bengal. This study assesses the floral biology, floral volatile organic compounds (VOCs), and floral visitors of the weed. The weed species flowers from October to January. Florets are white to purple, with short, narrow corolla tubes and deep-seated nectar. Abundant VOCs are benzyl stearate, 2,4-decadienal, n-hexadecanoic acid, 1-hexyl-2-nitrocyclohexane, and o-decyl hydroxylamine. Flower heads were visited by numerous insect groups, though the diversity of Lepidoptera (mainly butterflies) was higher than the other insect orders. The weed is pollinated by diverse insect groups (e.g., butterflies, flies, honeybees, leafcutter bees, solitary bees, and wasps). However, vital pollination services to the weed were provided by butterflies (based on the ‘approximate pollination value’). Our findings may conclude that the clustered capitula, longer stigmatic receptivity, and broad array of pollinators resulted in too much fruit set. It is one of the critical factors that support the high growth rate and invasive nature of the weed in dry habitats.

Non-targeted NMR approach to unveil and promote the biodiversity of globe artichoke in the Mediterranean area

The globe artichoke is an important constituent of the Mediterranean diet, being rich in bioactive compounds. Artichoke is widely cultivated in Italy, especially in the Apulia region, with a multitude of local varieties. Most of this genetic material is endangered and its metabolic profile is not yet characterized. In this work, we aimed at dissecting landrace biodiversity by characterizing the metabolic profiles of edible hearts, i.e. the edible inner part of the flower heads, and external bracts of artichoke flower heads, using a simple, fast, and affordable analytical methodology. A non-targeted spectroscopic approach combining NMR experiments and multivariate data analysis provided a comprehensive picture of the chemical composition of 16 artichoke landraces, some of which are at risk of extinction. A special focus was on hydrosoluble compounds, contributing to the functional food value of the artichoke. Moreover, a possible correlation between the metabolic composition and the head color was established.Our analyses highlight the nutraceutical diversity and value of newly studied artichoke landraces. Specifically, the hearts of the deep purple-colored "Nero del Salento" are rich in both mono- and dicaffeoylquinic acids along with inulin, while the hearts of the green "Bianco di Taranto" and "Centofoglie di Rutigliano" are characterized by a relatively higher content of dicaffeoylquinic acids. The results can help promote endangered local varieties for production and commercialization, against the ongoing genetic erosion and loss of crop diversity.

Phyllotaxis without symmetry: what can we learn from flower heads?

Phyllotaxis is commonly considered in the context of circular meristems or receptacles, yet non-circular (fasciated) structures also give rise to new primordia and organs. Here we investigate phyllotactic patterns in fasciated flower heads in the Asteraceae plant family. We begin by surveying the phenomenon of fasciation. We then show that phyllotactic patterns in fasciated heads can be generated by removing the inessential assumption of circularity from the previously published model of gerbera heads. To characterize these patterns, we revisit the conceptual framework in which phyllotactic patterns are commonly described. We note that some notions, in particular parastichies and parastichy numbers, maintain their significance in non-circular phyllotaxis, whereas others, in particular the divergence angle, need to be extended or lose their role. These observations highlight a number of open problems related to phyllotaxis in general, which may be elucidated by studies of fasciated heads.

Effects of shading and site conditions on vegetative and generative growth of a native grassland invader

Changes in grassland management lead to alterations in community structure and can facilitate rapid expansion of both non-native and native invaders. Light availability differs greatly depending on grassland density, and competition for light is an important component of species dynamics. In this study, we examined if light reduction is an effective method to suppress a native invader in pre-alpine meadows of low to moderate land-use intensity. Our study focused on the effects of shading and other site conditions on vegetative and generative growth of Jacobaea aquatica, a poisonous hemicryptophyte regionally spreading in C Europe. We hypothesized that negative shade effects occur in addition to suppression by high grassland productivity, moist climate and less intense management. Furthermore, we postulated that shading affects vegetative growth more than reproduction. To understand the effects of shading we conducted a greenhouse experiment with plants grown under different shading nets. These results were compared to data gathered from 20 field sites that represented a distinct gradient in grassland management and shading. Overall, performance of generative J. aquatica plants was reduced by shading in the greenhouse, while density of vegetative plants was reduced in the field. In the greenhouse, plants affected by shading had significantly fewer flower heads and slightly smaller rosettes. Under field conditions, shading effects occurred together with additional environmental factors, while density of vegetative plants was significantly reduced by shading. Our data show that while realising high shading effects in the field is hard to accomplish, light reduction still has an influence on plant performance and population density, and could therefore be used to suppress the invasive native J. aquatica. In low to moderate intensity grasslands, suppression can be achieved by delaying the first mowing, thus enhancing shading. We conclude that manipulating environmental filters to increase resource competition is recommended as an alternative management tool to control the abundance of invasive native plants in grassland.

Evaluation of ‘Lorca’ Cultivar Aptitude for Minimally Processed Artichoke

Previous research works have reported that ‘Lorca’ artichoke cultivar presents a lower total phenolic content than other cultivars rich in phenolic compounds, which could show a lower susceptibility to enzymatic browning and increase its aptitude for fresh-cut processing. The aim of this study was to analyze the total phenolic content as well as browning evaluation by image analysis and polyphenol oxidase (PPO) enzyme activity in ‘Lorca’ cultivar in order to characterize the key factors which influence its phenolic levels for minimally processed artichokes. Thus, artichokes were harvested and classified on three head orders (main, secondary, and tertiary), as well as three development stages (initial, intermediate, and advanced). Variance components analysis was carried out for total phenolic content considering three factors: plant, flower head order, and internal development stage. For the first time, the internal development stage has been related to total phenolic content, and results showed that artichoke head order and internal development stage were responsible for a variability of 22.17% and 15.55%, respectively. Main artichoke heads and those at the advanced development stage presented the lowest phenolic concentration as well as the lowest PPO activity; therefore, they exhibit the lowest browning process, which could increase their use in ready-to-eat products at market.

Chemical Antioxidant Quality Markers of Chrysanthemum morifolium Using a Spectrum-Effect Approach.

Traditionally, the quality evaluation of Chrysanthemum morifolium (CM) cv. (Juhua) attributes its habitats and processing methods, however, this strategy of neglecting bioactive ingredients usually results in deviation of quality evaluation. This study aims to explore the quality marker (Q-marker) based on spectrum-effect relationship and quality control strategy of CMs. The chromatographic fingerprint of 30 flower head samples of CMs from five different habitats including Hang-baiju, Gongju, Huaiju, Taiju and Boju were constructed by high performance liquid chromatography and analyzed through chemometrics methods such as similarity analysis (SA), cluster analysis (CA) and principal component analysis (PCA). The common peaks were quantified by external standard method and relative correction factor method. The in-vitro radical scavenging capacity assays of DPPH·, ·OH and ABTS were carried out. The Q-marker was explored by the correlation analysis between the contents of common peaks and in-vitro radical scavenging capacity, and then used to evaluate the quality of 30 flower head samples of CMs. A total of eight common peaks were appointed in 30 flower head samples of CMs, and their similarities ranged from 0.640 to 0.956. CA results showed that 30 flower head samples of CMs could be divided into five categories with reference to the Euclidean distance of 5. PCA results showed that common peaks played a major role in differential contribution of CMs. The quantification of common peaks hinted that their contents possessed significant variation whether for different accessions or the same accessions of CMs. The correlation analysis showed that chlorogenic acid, 3,5-O-dicaffeoylquinic acid, unknown peak 1, 4,5-O-dicaffeoylquinic acid and kaempferol-3-O-rutinoside could be used as the Q-markers for the quality evaluation of 30 flower head samples of commercially available CMs. The analysis strategy that combines chromatographic fingerprint analysis, multiple ingredients quantification, in-vitro chemical anti-oxidant activity evaluation and spectrum-effect relationship analysis clarified the therapeutic material basis and discovered the Q-markers, which possibly offers a more comprehensive quality assessment of CMs.

Soil and Vegetation Drive Sesquiterpene Lactone Content and Profile in Arnica montana L. Flower Heads From Apuseni-Mountains, Romania.

Arnica montana L. (AM, Asteraceae) is a perennial, herbaceous vascular plant species of commercial importance. The flower heads’ pharmacological properties are attributed mainly to sesquiterpene lactones (SLs), with phenolic acids and flavonoids also considered of relevance. The botanical drug is still partly collected in different European mountain regions. The SL content can be influenced by genetic factors and environmental conditions (altitude, temperature and rainfall). Surprisingly, the influence of the soil on SL-content have rarely been investigated. However, the soil determines the occurrence, distribution and overall fitness of AM. Equally, environmental factors are crucial determinants for the biosynthesis and fluctuations in plant secondary metabolites. Therefore, different abiotic (pH, C/N ratio, base saturation, cation exchange capacity) and biotic (species richness, vegetation cover) parameters need to be assessed as potential drivers of the variable content of AM’s secondary metabolites. Consequently, we developed an in situ experimental design aiming to cover a wide range of soil pH conditions. We detected and investigated different AM populations growing in grassland on acidic soils, on siliceous as well as calcareous geologies within the same geographical region and altitudinal belt. The total SL content and most single SL contents of the AM flower heads differed significantly between the two geologies. AM flower heads of plants growing on loam on limestone showed a significant higher total SL content than the flower heads of plants growing in siliceous grasslands. Furthermore, the SL contents were significantly correlated with geobotanical species richness and vegetation cover pointing toward an effect of species interactions on the production of SLs. Moreover, the ratios of the main SLs helenalin to dihydrohelenalin esters were significantly correlated to environmental parameters indicating that SL composition might be a function of habitat conditions. The findings of this study shed light upon the often ignored, complex interactions between environmental conditions and plant secondary metabolites. We highlight the importance of both abiotic and biotic habitat parameters for SLs in AM.

Accumulation Patterns of Six Pyrethrin Compounds across the Flower Developmental Stages—Comparative Analysis in Six Natural Dalmatian Pyrethrum Populations

Pyrethrin is a specialized metabolite of Dalmatian pyrethrum (Tanacetum cinerariifolium (Trevir.) Sch. Bip.), Asteraceae, known worldwide as an effective bioinsecticide. It consists of six active compounds: Pyrethrin I and II, cinerin I and II, and jasmolin I and II. Pyrethrin accumulates mainly in the flower heads and its content depends on numerous factors, such as the flower developmental stage. This study aims to investigate the accumulation patterns of six pyrethrin compounds in the flower heads of Dalmatian pyrethrum over the eight developmental stages (FS1 to FS8), and to make a comparison in six natural populations. Ultrasound assisted extraction was used to extract the pyrethrin, while qualitative and quantitative analysis was performed by High performance liquid chromatography. The accumulation patterns of different pyrethrin compounds were generally similar and also synchronous between different populations, while the pyrethrin I/pyrethrin II ratio showed irregular patterns. In all populations studied, the highest increase of all compounds was observed from FS1 to FS2. Their concentration continuously increased, reaching the highest values at FS4 stage (2–5 rows of open disc flowers), and generally decreased gradually towards FS6 or FS7 and then stagnated until the FS8 stage. Despite the very similar accumulation pattern of pyrethrin compounds in the different populations, the significant differences in their content suggest a different genetic background. Knowledge of the dynamics of pyrethrin compounds accumulation across flower development stages is valuable for determining the optimal harvest time of pyrethrum flower heads.

First Report of Fusarium graminearum Causing Flower Blight On Hemp (Cannabis sativa) in Kentucky.

In October of 2020, a grower in Boyle County, KY, reported mold and blight symptoms on flowers of field-grown hemp. Plants were approaching harvest, and the mold was affecting 100% of the cultivar 'White CBG' being grown for cannabinoid (CBD) extraction. Mycelium colonized the flower heads and any seeds within bracts. Affected flower bracts were necrotic, and mycelium and necrosis in the most severe cases also encompassed adjacent (sugar) leaves. Necrotic symptomatic tissue was collected, disinfested in 10% bleach for one minute, and cultured on acidified potato dextrose agar (APDA). Each isolate was single-spored, transferred to PDA, stored in 15% glycerol at -80°C and maintained at room temperature under blacklight blue and fluorescent bulbs on a 12-hour light-dark cycle. Colonies produced white-pink mycelia with a dark red pigment on the undersides. Conidia collected after 7-9 days were falcate and septate (5 to 6). No microconidia were produced. Macroconidia measured 35.4-49.7 µm x 3.4-5.8 µm (n=50). The strains produced blue-black fertile perithecia on carrot agar when induced according to the method of (Bowden and Leslie, 1999). To confirm pathogenicity, flowers of hemp cultivars 'Lifter', 'Trump Towers', 'Wife' and 'White CBG' were inoculated in the greenhouse with a representative fungal strain (20Hemp010). Plants were inoculated at two different stages: when the styles were still green or after they had become senescent. Macroconidia were collected from 7- to 9-day-old cultures grown under a 12-hour light-dark cycle. Plants were spray-inoculated with a 5 x 105 per ml conidial suspension in 0.05% Tween 20 until runoff. Flower heads were individually covered with clear plastic bags and incubated for 72 h at 95-100% humidity under greenhouse benches to avoid direct light. Bags were removed after 72 h and returned to the bench. Greenhouse conditions were 23-25°C with a 14-hour photoperiod and 50% RH. Symptoms developed 7 dai in 1% of the flowers inoculated when styles were green, and 36% of the flowers that had senescent styles. Symptoms were similar to those initially noticed in Boyle County, including necrotic flower bracts and sugar leaves, and visible fungal growth. Symptoms were more severe on plants inoculated when styles were necrotic. Recovered fungi were morphologically similar to 20Hemp010. Genomic DNA was extracted from the mycelium with the Zymo Research Quick-DNA Fungal/Bacterial Miniprep Kit. A fragment of the translation elongation factor 1-alpha 1 gene was amplified with primers EF1 and EF2 as described by (O'Donnell et al. 1998). Amplicons were sequenced and the consensus (MZ407909) was compared with the NCBI GenBank Refseq database by BLASTn. The top hit was Fusarium graminearum with 100% identity (JF270185.1). Pairwise alignments via MycoBank Fusarium MLST and Fusarium-ID also revealed a top hit of F. graminearum with 100% identity (AY452957.1). Conidial and colony morphology were also consistent with F. graminearum (Leslie and Summerell, 2006), thus we conclude that this species was the causal agent of the flower blight and mold. The same disease was subsequently confirmed on hemp in Breathitt and Franklin Counties in KY in 2020. This is the first report of this disease in KY, although F. graminearum has been reported previously causing a similar flower blight on hemp in NY and NC (Bergstrom et al., 2019, Thiessen et al. 2020). Fusarium graminearum is common in KY as a cause of Fusarium head blight on wheat and Gibberella ear rot on corn. In cereals, fungal infection is facilitated by the production of the mycotoxin deoxynivalenol (DON), which is harmful to humans and livestock (Desjardins and Hohn, 1997). As hemp production in Kentucky continues to rise for production of CBD products and edible grains, accumulation and concentration of DON in these products could become a concern.