Centaurea Solstitialis Research Articles

Anti-cancer and anti-inflamatory effects of Centaurea solstitialis extract on human cancer cell lines

Anti-cancer and anti-inflamatory effects of Centaurea solstitialis extract on human cancer cell lines

Potential limits to the benefits of admixture during biological invasion.

Species introductions often bring together genetically divergent source populations, resulting in genetic admixture. This geographic reshuffling of diversity has the potential to generate favourable new genetic combinations, facilitating the establishment and invasive spread of introduced populations. Observational support for the superior performance of admixed introductions has been mixed, however, and the broad importance of admixture to invasion questioned. Under most underlying mechanisms, admixture's benefits should be expected to increase with greater divergence among and lower genetic diversity within source populations, though these effects have not been quantified in invaders. We experimentally crossed source populations differing in divergence in the invasive plant Centaurea solstitialis. Crosses resulted in many positive (heterotic) interactions, but fitness benefits declined and were ultimately negative at high source divergence, with patterns suggesting cytonuclear epistasis. We explored the literature to assess whether such negative epistatic interactions might be impeding admixture at high source population divergence. Admixed introductions reported for plants came from sources with a wide range of genetic variation, but were disproportionately absent where there was high genetic divergence among native populations. We conclude that while admixture is common in species introductions and often happens under conditions expected to be beneficial to invaders, these conditions may be constrained by predictable negative genetic interactions, potentially explaining conflicting evidence for admixture's benefits to invasion.

Evidence for evolution of increased competitive ability for invasive Centaurea solstitialis, but not for naturalized C. calcitrapa

Congeneric species with the same native and non-native ranges, but exhibiting different invasiveness, provide opportunities to assess the relative importance of factors contributing to successful invasions. For example, comparing the competitive ability of such congeners against other species from the native and non-native regions of invasive species can provide insight into the role of evolutionary experience with different competitors. We selected two congeneric Centaurea species with overlapping native and non-native ranges but with strikingly different invasive success, Centaurea solstitialis and C. calcitrapa, and conducted experiments with populations from each region using a suite of different native grass species from each region. When grown with Spanish grass species, competitive responses were 32% stronger for C. calcitrapa and 30% stronger for C. solstitialis, than when in competition with grasses native to California. Centaurea solstitialis from California had 66% higher competitive effects on grasses, all species considered together, than Spanish C. solstitialis; whereas the competitive effects of C. calcitrapa on grasses were not significantly different between C. calcitrapa ranges. Our results are consistent with the prediction that the evolution of increased competitive ability (EICA) might contribute to the devastating success of C. solstitialis in California, and that its absence might contribute to the modest naturalization of the non-invasive C. calcitrapa. Escape from the strong competitive effects and responses of grasses from Spain may also contribute to invasive success in California. Our results suggest that studies of EICA should be based on competitive tests, since biomass alone is not always a good predictor of competitive ability.

Site conditions determine a key native plant's contribution to invasion resistance in grasslands.

Many plant invasion studies in grasslands suggest that resident plants that share functional traits with invaders can reduce invasion by competing for limiting resources. However, since invasion studies often occur in highly controlled plots or microcosms, it is unclear how heterogeneous site conditions alter competitive interactions under realistic scenarios. To explore how landscape heterogeneity affects biotic resistance provided by competitive resident plants, we conducted a field-based experiment across four sites in California grasslands. Plots contained naturally occurring populations of native Hemizonia congesta, but differed in other characteristics, including litter cover, annual grass cover, soil moisture, and species richness. We invaded plots with the functionally similar nonnative Centaurea solstitalis (yellow starthistle) and, at one site, supplemented one-half of the established plots with water to test the effects of increasing a limiting resource. As in simplified plots and microcosms, increasing H.congesta abundance reduced starthistle biomass by competing for limited soil moisture, but only in plots with high starthistle germination. We conclude that higher abundances of native H.congesta can reduce starthistle invasion in heterogeneous grasslands, but competition is also affected by both abiotic (soil moisture) and biotic (starthistle germination number) conditions that vary across sites.

Seeding plants for long-term multiple ecosystem service goals

The historical management of agroecological systems, such as California's rangelands, have received criticism for a singular focus on agricultural production goals, while society has shifting expectations to the supply of multiple ecosystem services from these working landscapes. The sustainability and the multiple benefits derived from these complex social-ecological systems is increasingly threatened by weed invasion, extreme disturbance, urban development, and the impacts of a rapidly changing and increasingly variable climate. California's grasslands, oak savannas, and oak woodlands are among the most invaded ecosystems in the world. Weed eradication efforts are rarely combined with seeding on these landscapes despite support for the inclusion of the practice in a weed management program. Depending on seed mix choice, cost and long-term uncertainty, especially for native seed, is an impediment to adoption by land managers. We investigated four seeding mixes (forage annual, native perennial, exotic perennial, and exotic-native perennial) to evaluate how these treatments resist reinvasion and support the delivery of simultaneous multiple ecosystem services (invasion resistance, native richness, nitrogen fixing plants, pollinator food sources, plant community diversity, forage quality, and productivity). We found the increase of exotic and native perennial cover will drive resistance to an invading weedy summer flowering forb Centaurea solstitialis but provides a mixed response to resisting invasive annual grasses. The resistance to invasion is coupled with little tradeoff in forage productivity and quality and gains in plant diversity and native cover.

Essential Oil and Fatty Acid Composition of Centaurea solstitialis ssp. solstitialis

Centaurea is a widespread genus from Asteraceae family in Turkey. There are plenty of researches about fatty acid and essential oil profiles of Centaurea species. Essential oils were obtained using a Clevenger apparatus by hydrodistillation from aerial part of the plant. The essential oil composition of the plant was identified by GC-MS using FID detector. 31 compounds representing 91.5% were identified. Hexadecanoic acid (50.2%) and tetradecanoic acid (10.1%) were found to be the major compounds. For fatty acids, fatty acid methyl esters (FAMEs) were prepared. The fatty acid compositions were analyzed by GC. Saturated fatty acids (SFAs) were totally 25.05%, monounsaturated fatty acids (MUFAs) were 19.60% and polyunsaturated fatty acids were 19.86%. The major compounds were found as oleic acid (18.54%), linoleic acid (10.07%), palmitic acid (8.28%), stearic acid (6.82%) and ℽ- linoleic acid (6.75%).

A new species and observations on the genus Ramularia from Iran

Ramularia ranunculicola sp. nov. (Mycosphaerellaceae) is described from Iran on Ranunculus muricatus and compared with other species reported on Ranunculus spp. Ramularia carletonii on Lactuca tuberosa and R. nagornyi on Centaurea solstitialis are newly reported from Iran, and Picris strigosa is a new host for R. picridis (= R. inaequalis s. lat.).

Qualitative characterization of cultivated and wild edible plants: mineral elements, phenols content and antioxidant capacity

This study investigated the qualitative characteristics of several edible wild herbaceous species, including those most consumed in Foggia Province (southern Italy). Analysis of qualitative characteristics was performed for the edible parts of 11 wild species (Beta vulgaris L., Foeniculum vulgare Miller, Centaurea solstitialis L., Cichorium intybus L., Scolymus hispanicus L., Sonchus oleraceus L., Borago officinalis L., Diplotaxis erucoides L., Diplotaxis tenuifolia (L.) DC, Sinapis arvensis L., Portulaca oleracea L.) and three cultivated species (C. intybus, B. officinalis, D. tenuifolia). The plants were collected from areas in the Foggia countryside, and the edible part of each species was analysed for dry matter, protein, cation and anion contents as well as total phenols and antioxidant activities. Among the cations, calcium was the most differentiated among species, ranging 784 mg kg-1 fresh weight (Fw) for B. vulgaris to 5886 mg kg-1 Fw for S. hispanicus. The nitrate contents were also highly variable, from 75 mg kg-1 Fw for C. intybus to 3874 mg kg-1 Fw for D. tenuifolia. Total polyphenols ranged from 1054 mg GAE mg kg-1 Fw for C. solstitialis to 3664 mg GAE mg kg-1 Fw for S. arvensis. Antioxidant activities ranged from 839 mg TE kg-1 Fw for B. vulgaris to 5658 mg TE kg-1 Fw for C. intybus. Significant differences were also noted between wild and cultivated plants in the qualitative parameters. Total polyphenols and antioxidant activity were higher in wild C. intybus and B. officinalis than in their cultivated counterparts. Multivariate analysis (cluster analysis and linear discriminant analysis) allowed integration of the ANOVA data to determine the qualitative characteristics of the wild species that contribute most to group differences. The results of the present study aims at improve the current knowledges about edible wild species as vegetable sources in the Mediterranean diet.

Climate Dynamics, Invader Fitness, and Ecosystem Resistance in an Invasion-Factor Framework

As researchers and land managers increasingly seek to understand plant invasions and the external (climate) and internal (plant genetics) conditions that govern the process, new insight is helping to answer the elusive question of what makes some invasions successful and others not. Plant invasion success or failure is based on a combination of evolutionary and ecological processes. Abiotic (e.g., climate) and biotic (e.g., plant competition) conditions in the environment and plant genetics (e.g., fitness) combine in either decreasing or increasing invasion, yet it has proven challenging to know exactly which of these conditions leads to success for a given species, even when a wealth of empirical data is available. Further, current regional distribution models for invasive plant species rarely consider biotic and fitness interactions, instead focusing primarily on abiotic conditions. The crucial role of all three factors (climate dynamics, invader fitness, and ecosystem resistance) must not be ignored. Here we construct a three-factor invasion framework from which we develop conceptual models using empirical studies for yellow starthistle, nonnative common reed, and musk thistle, three dissimilar but commonly occurring invasive plant species in North America. We identify how components of the invasion process—rapid population increase, established local dominance, and rapid range expansion—are influenced by ecosystem resistance, invader fitness, and/or climate dynamics, a set of broadly defined factors for each of the three invasive plant species. Our framework can be used to (1) establish research priorities, (2) address gaps in theoretical understanding, and (3) identify invasion process components that can be targeted to improve management. Building on previous models, our unifying framework, which can be used for assessing any invasive plant species having sufficient empirical data, simultaneously shows the influence of ecosystem resistance, invader fitness, and climate dynamics factors on the invasion process.

Extensive analysis of native and non-native Centaurea solstitialis L. populations across the world shows no traces of polyploidization.

Centaurea solstitialis L. (yellow starthistle, Asteraceae) is a Eurasian native plant introduced as an exotic into North and South America, and Australia, where it is regarded as a noxious invasive. Changes in ploidy level have been found to be responsible for numerous plant biological invasions, as they are involved in trait shifts critical to invasive success, like increased growth rate and biomass, longer life-span, or polycarpy. C. solstitialis had been reported to be diploid (2n = 2x = 16 chromosomes), however, actual data are scarce and sometimes contradictory. We determined for the first time the absolute nuclear DNA content by flow cytometry and estimated ploidy level in 52 natural populations of C. solstitialis across its native and non-native ranges, around the world. All the C. solstitialis populations screened were found to be homogeneously diploid (average 2C value of 1.72 pg, SD = ±0.06 pg), with no significant variation in DNA content between invasive and non-invasive genotypes. We did not find any meaningful difference among the extensive number of native and non-native C. solstitialis populations sampled around the globe, indicating that the species invasive success is not due to changes in genome size or ploidy level.

Forage seeding in rangelands increases production and prevents weed invasion

Increasing forage productivity in the Sierra foothill rangelands would help sustain the livestock industry as land availability shrinks and lease rates rise, but hardly any studies have been done on forage selections. From 2009 to 2014, in one of the first long-term and replicated studies of seeding Northern California's Mediterranean annual rangeland, we compared the cover of 22 diverse forages to determine their establishment and survivability over time. Among the annual herbs, forage brassica (Brassica napus L.) and chicory (Cichorium intybus L.) proved viable options. Among the annual grasses, soft brome (Bromus hordeaceus) and annual ryegrass (Lolium multiflorum) performed well. However, these species will likely require frequent reseeding to maintain dominance. Long-term goals of sustained dominant cover (> 3 years) are best achieved with perennial grasses. Perennial grasses that persisted with greater than 50% cover were Berber orchardgrass (Dactylis glomerata), Flecha tall fescue (Lolium arundinaceum) and several varieties of hardinggrass (Phalaris aquatica L., Perla koleagrass, Holdfast, Advanced AT). In 2014, these successful perennials produced over three times more dry matter (pounds per acre) than the unseeded control and also suppressed annual grasses and yellow starthistle (Centaurea solstitialis L.) cover.

Spatiotemporal variation in the strength of density dependence: implications for biocontrol of Centaurea solstitialis

Invasive plants often occupy large ranges in the introduced region and consequently, local population dynamics vary in ways that affect the potential for biological control. We used matrix models to describe how density and population growth rate of Centaurea solstitialis varies in time and space. Matrix models were parameterized with data collected over 4 years from invasions at the coast, interior valleys and Sierra Nevada Mountains in California (USA). Asymptotic population growth rates (λ) varied dramatically across all populations and years (0.24–6.45), density varied by an order of magnitude and had a measurable effect on survival and λ in all populations. We used simulations to estimate the degree to which a biocontrol agent would need to reduce plant survival to control the weed. Because seedling survival was dependent on density, an agent that reduced seedling density had the effect of increasing the probability that the remaining plants survived to flowering. Interestingly, this meant that in the highest density populations the plant had the largest compensatory response to agent attack and experienced decline (λ ≤ 1.0) only after heavy losses (≥90%) to the agent. Conversely, in populations where density was so low that it had only a weak effect on survival, the agent was able to control the plant (λ ≤ 1.0) at much lower levels of attack (≤50%). In other words, the impact of a biocontrol agent is predicted to be lower where the plant reaches its highest densities because the surviving plants, now experiencing less intraspecific competition, are more likely to survive to flowering and produce more seeds. This may also be true for other invasive species in which strong density dependent processes are operating. For this reason, prospective agents ought to target density-independence vital rates.

Host specificity of Aceria centaureae (Nalepa), a candidate for biological control of Centaurea dίffusa De Lamarck

Filed collected rosettes or twigs of Centaurea diffusa De Lamarck, infested by the gall mite Aceria centaureae, were fixed onto appropriately grown and planted test plants of ten different species in the area of Thessaloniki, Greece, in 1985 and 1986. The test plants were inspected for presence of galls and mites a few to several days after their contact with the infested twigs. Gall formation occurred on all of the Centaurea diffusa test plants, either of Greek or U.S. origin, and on some of the Centaurea solstitialis, L. test plants. No galls or other mite damage could be found on the other test plants, which were Carthamus tinctorius L. (safflower), Cirsiton creticion (De Lamarck) D’Urville, of local origin and six Cirsium species of U.S. origin, i.e. cymosum (Greene) J. T. Howell, occidentals (Nutt) Jeps., pastoris Howell, andersonii (Gray) Petrak, brevistylum Crong; and undulation (Nutt.) Spreng. These results suggest that A. centaureae most probably has a very restricted host plant range, feeding only on weedy Centaurea spp. Thus the mite should be considered as a possible candidate for biological control of diffuse knapweed in the U.S.A. and Canada.

Bee visitors of Centaurea solstitialis L. (Asteraceae) in an urban environment in northwestern Turkey

Information on the pollination ecology and floral visitors of the noxious weed Centaurea solstitialis is available for several populations in its invasive range, but limited information is available in its native range, with most studies conducted on the Greek island of Lesvos. Herein, we document the visitation pattern of bees and explore the relationship of bee body size and nectar availability in weedy populations of C. solstitialis from an urban environment within its native range in northwestern Turkey. Studies were conducted at patches of C. solstitialis in abandoned lots at the Uludag University near the city of Bursa. A total of 41 species, including honey bees, belonging to five families and 19 genera were recorded. Small megachilid and halictid bee species were the most common visitors. Average nectar standing crop volume per floret was low (0.003–0.117 μL) and did not significantly vary throughout the day. Average bee head width significantly correlated with average nectar standing crop volume but did not significantly change throughout the day. Analyses of pollen loads as well as direct observations of bee foraging behavior indicate that a large number of bees visit C. solstitialis, primarily in search of nectar while carrying a large percentage of pollen grains of this plant species on their bodies. These results are similar to previous observations on a non-weedy population of C. solstitialis from the island of Lesvos.

Environmental Variables Influence the Association of Eustenopus villosus and Larinus curtus (Coleoptera: Curculionidae) Adults With Different Growth Stages of the Invasive Thistle Centaurea solstitialis (Asteraceae: Cardueae) in Washington State.

A 2-yr (2014-2015) field study in eastern Washington State quantified the effect of environmental factors on the overwintered Eustenopus villosus (Boheman) and Larinus curtus (Hochhut) adults in relation to phenology of Centaurea solstitialis L. (Asteraceae: Cardueae), the feeding and breeding host for these two weevil biocontrol agents. We recorded in the study area: ambient and soil temperatures, soil moisture, percent cover and developmental stage of C. solstitialis, and presence of adults of each weevil species. Sampling took place from early May to mid-August. Weevil activity for both species in both years was segregated into three phases: 1 - a pre-appearance phase in which neither species was detected, 2 - appearance and increase in frequency, and 3 - decrease in frequency. Eustenopus villosus increase in frequency was most strongly associated with warming temperatures both years. Larinus curtus increase in frequency in 2014 was most associated with increasing C. solstitialis cover and in 2015 with warming temperatures and drying soils. In both years, both weevil species' decline in frequency was likely due to the advancing C. solstitialis phenology. This pattern indicates that the appearance and increase in frequency of the overwintered E. villosus and L. curtus adults was likely a function of warming temperatures. Both species' decline in frequency was likely a function of the weevils completing their life cycle in synchrony with the phenological advancement of C. solstitialis and decline of abundant breeding and foraging sites (buds and flowers).

Population genomic analyses reveal a history of range expansion and trait evolution across the native and invaded range of yellow starthistle (Centaurea solstitialis)

Identifying sources of genetic variation and reconstructing invasion routes for non-native introduced species is central to understanding the circumstances under which they may evolve increased invasiveness. In this study, we used genome-wide single nucleotide polymorphisms to study the colonization history of Centaurea solstitialis in its native range in Eurasia and invasions into the Americas. We leveraged this information to pinpoint key evolutionary shifts in plant size, a focal trait associated with invasiveness in this species. Our analyses revealed clear population genomic structure of potential source populations in Eurasia, including deep differentiation of a lineage found in the southern Apennine and Balkan Peninsulas and divergence among populations in Asia, eastern Europe and western Europe. We found strongest support for an evolutionary scenario in which western European populations were derived from an ancient admixture event between populations from eastern Europe and Asia, and subsequently served as the main genetic 'bridgehead' for introductions to the Americas. Introductions to California appear to be from a single source region, and multiple, independent introductions of divergent genotypes likely occurred into the Pacific Northwest. Plant size has evolved significantly at three points during range expansion, including a large size increase in the lineage responsible for the aggressive invasion of the California interior. These results reveal a long history of colonization, admixture and trait evolution in C.solstitialis, and suggest routes for improving evidence-based management decisions for one of the most ecologically and economically damaging invasive species in the western United States.

Phytochemical and Cytogenetic Characterization of Centaurea solstitialis L. (Asteraceae) from Croatia.

The cytogenetic characterization of Centaurea solstitialis L. (Asteraceae) showed a chromosome number of 2n=16. Karyotype is composed by four pairs of metacentric, two pairs of submetacentric and two pairs of subtelocentric chromosomes. Physical mapping of two rDNA probes revealed two loci of 35S and one locus of 5S rRNA genes. Chromomycin fluorochrome banding revealed that all rDNA loci were GC rich. The genome size (2C-value) of 1.95pg classes this species in the group of very small genomes. Chemical composition of C.solstitialis volatile oil (VO) from Croatia, studied with gas chromatography-mass spectrometry showed dominant components as it follows: hexadecanoic acid, α-linolenic acid, germacrene D and heptacosane. Antioxidant capacity, measured by ferric reducing power assay and 2,2-diphenyl-1-picrylhydrazyl methods, as well as inhibition of acetyl- and butyrylcholinesterase of VO was lower comparing to a standard solutions. Volatile oil tested with disc diffusion method showed good inhibitory potential against Pseudomonas aeruginosa, Escherichia coli and all tested fungi: Candida albicans, Penicillium funiculosum and Aspergillus fumigatus. The microdilution method showed best activity against Chronobacter sakazakii and A.fumigatus.

Assessing the biological control of yellow starthistle (Centaurea solstitialis L): prospective analysis of the impact of the rosette weevil (Ceratapion basicorne (Illiger))

Yellow starthistle (Centaurea solstitialis L) (YST) is an invasive weed native to the Mediterranean region with a geographical centre of diversity in Turkey. It is widely established in Chile, Australia, and western North America. It arrived in California as a contaminant in alfalfa seed in 1859 and, by 2002, had infested >7.7 million hectares in the U.S.A. Biological control of YST using capitula feeding weevils, picture wing flies and a foliar rust pathogen has been ongoing in the western U.S.A. for more than three decades with limited success. Modelling and field research suggest natural enemies that kill whole plants and/or reduce seed production of survivors are good candidates for successful biological control. A candidate species with some of these attributes is the rosette weevil Ceratapion basicorne (Illiger). In the present study, a model of the rosette weevil is added to an extant system model of YST and its capitula feeding natural enemies and, in a GIS context, is used to assess YST control in the Palearctic region and the weevil's potential impact on YST in western U.S.A. The results obtained suggest densities of mature YST plants in western U.S.A. would be reduced by 70–80% in many areas.

Performance of one-class classifiers for invasive species mapping using airborne imaging spectroscopy

Most remote sensing approaches for mapping invasive plant species focus on species in a prominent phenological stage, such as during flowering, and do not systematically evaluate the performance for mapping lower cover fractions. In this study, we used airborne imaging spectroscopy (also known as hyperspectral imaging) to detect the invasive grass Phalaris aquatica and the invasive herb Centaurea solstitialis in a pre-flowering stage in the Jasper Ridge Biological Preserve, California, and compared the performance of three different one-class classifiers: Maxent, biased support vector machines and boosted regression trees.We collected presence data for C. solstitialis and P. aquatica to calibrate each approach and additional presence-absence data to validate model performance on 3m×3m plots. The imaging spectroscopy data were acquired using the Carnegie Airborne Observatory Visible-to-Shortwave Infrared (VSWIR) imaging spectrometer (400–2500nm range) with a pixel size of 1m×1m.The resulting overall accuracies were 72–74% for C. solstitialis, and 83–88% for P. aquatica. For both species, the overall performance was slightly better for Maxent and BRT than for biased SVM. The detection rates for low cover plots were considerably higher for C. solstitialis than for P. aquatica. The models relied on different areas of the reflectance spectrum, but still produced the same general pattern of predicted species occurrences. We conclude that the different one-class classifiers allow for the detection and monitoring of target species with similar success rates.

Inter‐regional hybrids of native and invasive Centaurea solstitialis display intermediate competitive ability

Thanks to Margarita Zorrilla and to the Callaway Lab staff. RMC was funded by NSF‐DEB 0614406 and the NSF‐EPSCR Track‐1 EPS‐1101342 (INSTEP 3). DM was funded by Micinn (2008‐0662); by FCT (PCT/BIA‐PLA/3389/2012; IF‐00066‐2013); and by the EC (FP7‐PEOPLE‐MC‐CIG‐321909). FCT is partially funded by the EU via QREN, COMPETE and FEDER.