Dipsacus Fullonum Research Articles

Antibacterial activities of Dipsacus sylvestris Huds. against Borrelia burgdorferi s.s. in vitro

Antibacterial activities of Dipsacus sylvestris Huds. against Borrelia burgdorferi s.s. in vitro

AN IMPROVED FORMAL APPROACH TO DEMOGRAPHIC LOOP ANALYSIS

Loop analysis is introduced to demographic analysis as a tool to compare relative contributions of different life-history types to population growth rate. In 1998, G. M. Wardle brought in basic concepts of the graph theory to demographic loop analysis and proposed a methodology to determine the loops from any life-cycle graph based on these concepts. However, the mathematics behind Wardle's methodology cannot readily be used by most population ecologists. A new methodology that is also based on graph theory concepts but both makes ecological sense in its application and is simpler to implement is proposed. Three rules of thumb serve as the basis of the proposed methodology that brings a more systematic approach to loop selection: it identifies only those loops that are ecologically meaningful (i.e., loops that are forward-flowing and with positive elasticity values). Thus, it produces a loop set that is more amenable to answer questions on comparison of different lifehistory types. It is tested on several life-cycle graphs from the literature. Three of these are presented: Vouacapoua americana, Dipsacus sylvestris, and Alcyonium sp. In each case, the methodology successfully produced a loop set that makes sense in terms of the ecology of the species. The methodology is also implemented as a couple of open-source computer codes. It is hoped that the proposed methodology will lead to wider use of loop analysis in demographic population studies.

A New Species of <I>Leipothrix</I> (Acari: Prostigmata: Eriophyidae) on <I>Dipsacus</I> spp. in Europe and Reassignment of Two <I>Epitrimerus</I> spp. (Acari: Prostigmata: Eriophyidae) to the Genus <I>Leipothrix</I>

A new species of eriophyid mite, Leipothrix dipsacivagus n. sp. (Acari: Prostigmata: Eriophyidae), collected from Dipsacus laciniatus L. (Dipsacaceae) and Dipsacus fullonum L. in Serbia, Bulgaria, and France, is described and illustrated. Differential diagnosis is provided in comparison with Leipothrix knautiae (Liro) n. comb., and Leipothrix succisae (Roivainen) n. comb., two species that also are proposed here for reassignment from the genus Epitrimerus Nalepa to the genus Leipothrix Keifer, within the family Eriophyidae. L. dipsacivagus n. sp. is being investigated as a candidate for biological control of invasive Dipsacus spp. in the United States.

Mycoflora of seed of common teasel (Dipsacus fullonum) in Washington State

Seeds of standing common teasel ( Dipsacus fullonum ) were harvested in January 2007 in Pullman, Washington, and divided into two categories, symptomatic versus asymptomatic, on the basis of signs of fungal colonization at 10-50X magnification. The most common signs were pseudothecia of Davidiella tassiana . Fungi were recovered from all seeds of both categories when seeds were surface-disinfested and incubated on agar media. Aureobasidium pullulans accounted for 57-72% of fungal isolates from asymptomatic seed, but only 16-26% of isolates from symptomatic seed. Cladosporium spp. and Alternaria spp. exhibited a combined frequency of 54-64% from symptomatic seed, versus 16-35% from asymptomatic seed. Asymptomatic seed germinated at incidences of 44-76% whereas symptomatic seed germinated at incidences of 2-6%. When seeds or germinated seedlings were inoculated with conidial suspensions of representative isolates of Au. pullulans , C. herbarum (anamorph of D. tassiana ) or Alternaria sp., and incubated under conditions favorable for germination or growth of teasel, no differences were apparent between treated seed and non-inoculated control seed. The correlation between colonization by Alternaria and Cladosporium species and diminished germination ability probably reflects unidentified, predisposing factors for diminished germination. Immature pseudothecia of D. tassiana were repeatedly observed to germinate directly on the seed by production of fertile conidiophores from the apices of the papillae.

First Report of Powdery Mildew on Dipsacus sylvestris Caused by Sphaerotheca dipsacearum in North America

Common teasel (Dipsacus sylvestris) is a European species introduced into North America, and is now widely established and regarded as a noxious weed. In October 2005, a powdery mildew was observed on D. sylvestris in two locations in Pullman, Whitman Co., WA. Examination of diseased material confirmed that the causal agent was S. dipsacearum. This report provides the first documentation of S. dipsacearum on D. sylvestris in North America. Accepted for publication 20 April 2006. Published 7 June 2006.

Prospects for biological control of teasels, Dipsacus spp., a new target in the United States

Two closely related teasels (Dipsacales: Dipsacaceae, Dipsacus spp.) of European origin have become invasive weeds in the United States. Common teasel (Dipsacus fullonum L.) and cutleaf teasel (Dipsacus laciniatus L.) have likely been in North America for more than two centuries, having been introduced along with cultivated teasel [D. sativus (L.) Honckney], an obsolete crop plant. There are few records of American insects or pathogens attacking Dipsacus spp. Invasive teasels have recently begun to spread rapidly throughout much of their current range, for reasons that are not yet known. Common and/or cut-leaf teasel have been listed as noxious in five US states and as invasive in 12 other states and four national parks. Because the family Dipsacaceae is an exclusively Old World family, classical biological control is an important component of the overall management strategy of this weed in the US. Field surveys for natural enemies of D. fullonum and D. laciniatus in their native ranges and literature reviews of natural enemies of plants in the family Dipsacaceae have yielded 102 species of insects in six orders, as well as 27 fungi from 10 orders, three mites, one nematode, and two viruses. Due to the biennial nature of these weeds, a strategy to assign highest priority to biological control candidates attacking first-year (rosette) plants has been established. Candidates selected for further study based on this strategy include Chromatomyia ramosa (Hendel) (Diptera: Agromyzidae), Longitarsus strigicollis Wollaston (Coleoptera: Chrysomelidae), Epitrimerus knautiae Liro (Acarina: Eriophyiidae), Euphydryas desfontainii (Godart) (Lepidoptera: Nymphalidae), Erysiphe knautiae Duby (Erysiphales: Erysiphaceae), and Sphaerotheca dipsacearum (Tul. and C. Tul.) (Erysiphales: Erysiphaceae).

Leptosphaeria rubicunda . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Leptosphaeria rubicunda . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Although the fungus appears on dry stems of its hosts, which are mainly herbaceous, it is not known to cause any pathological symptoms. HOSTS: Apiaceae indet., Dipsacus sylvestris, Leonurus, Lythrum salicaria and Sambucus nigra . GEOGRAPHICAL DISTRIBUTION: NORTH AMERICA: Canada (Ontario), USA (New York). EUROPE: Czech Republic, Germany, Great Britain, Hungary, Italy. TRANSMISSION: Ascospores are dispersed by wind and rain-splash; the fungus presumably overwinters on dead host tissue and the ascospores are dispersed in the next favourable season.

DEMOGRAPHY AND DISPERSAL: CALCULATION AND SENSITIVITY ANALYSIS OF INVASION SPEED FOR STRUCTURED POPULATIONS

A fundamental characteristic of any biological invasion is the speed at which the geographic range of the population expands. This invasion speed is determined by both population growth and dispersal. We construct a discrete-time model for biological invasions that couples matrix population models (for population growth) with integrodifference equations (for dispersal). This model captures the important facts that individuals differ both in their vital rates and in their dispersal abilities, and that these differences are often determined by age, size, or developmental stage. For an important class of these equations, we demonstrate how to calculate the population's asymptotic invasion speed. We also derive formulas for the sensitivity and elasticity of the invasion speed to changes in demographic and dispersal parameters. These results are directly comparable to the familiar sensitivity and elasticity of population growth rate. We present illustrative examples, using published data on two plants: teasel (Dipsacus sylvestris) and Calathea ovandensis. Sensitivity and elasticity of invasion speed is highly correlated with the sensitivity and elasticity of population growth rate in both populations. We also find that, when dispersal contains both long- and short-distance components, it is the long-distance component that governs the invasion speed—even when long-distance dispersal is rare.

Demography and Dispersal: Calculation and Sensitivity Analysis of Invasion Speed for Structured Populations

A fundamental characteristic of any biological invasion is the speed at which the geographic range of the population expands. This invasion speed is determined by both population growth and dispersal. We construct a discrete-time model for biological invasions that couples matrix population models (for population growth) with integrodifference equations (for dispersal). This model captures the important facts that individuals differ both in their vital rates and in their dispersal abilities, and that these differences are often determined by age, size, or developmental stage. For an important class of these equations, we demonstrate how to calculate the population's asymptotic invasion speed. We also derive formulas for the sensitivity and elasticity of the invasion speed to changes in demographic and dispersal parameters. These results are directly comparable to the familiar sensitivity and elasticity of population growth rate. We present illustrative examples, using published data on two plants: teasel (Dipsacus sylvestris) and Calathea ovandensis. Sensitivity and elasticity of invasion speed is highly correlated with the sensitivity and elasticity of population growth rate in both populations. We also find that, when dispersal contains both long- and short-distance components, it is the long-distance component that governs the invasion speed—even when long-distance dispersal is rare.

Palaeoenvironments and cultural landscapes of the last 2000 years reconstructed from pollen and Coleopteran records in the Lower Rhône Valley, southern France

For the first time, a high-resolution pollen/Coleoptera joint analysis is performed on a late Holocene sedimentary sequence located in the Lower Rhône Valley. 14C dates validated by pollen data show that the bottom of the sequence is contemporaneous with the Greco-Roman period whereas the top is attributed to the present. This sequence yielded very rich pollen and insect assemblages, enabling a detailed reconstruction of the palaeoenvironment succession during the two last millennia around the site itself and more widely in the Arles plain. The very low pollen representation of trees and the near absence of tree-dependent Coleoptera suggest a marked deforestation of the area. The abundance of dung-beetles and nitrophytes is also in keeping with a strong grazing impact throughout the sequence. Three agricultural phases reflecting a growing level of human activities are identified. Phase 1 is contemporaneous with Celto-ligurian, Greek and Roman civilizations in Provence. At this time the forest cover was already largely destroyed, and pastoralism, cultivation of cereals, olives, vines and walnuts, was practised. Phase 2 is contemporaneous with a period spanning the Merovingian time and the Upper Middle Ages. It is characterized by increased agro-pastoral activities, probably related to the establishment of a monastic community at the Montmajour Abbey and to the settlement of farmers on the nearby Castellet hill. The major characteristic of agricultural phase 3 is the very high pollen percentages of Dipsacus fullonum or teasel, which was formerly extensively cultivated for cloth teasing. This early cultivation of an industrial plant, dated at La Calade to the twelfth century, is recorded for the first time in Provence. It may be connected with craft industries performed by monks at Montmajour Abbey. The sedimentological data suggest a succession of two stability phases interrupted by three flood phases. This interpretation agrees both with insect data, the fluctuating abundances of which are certainly connected with the alternation of ground submersion and dry periods, and with pollen data, marked by the impact of the floods upon the marshy veg etation. However, no clear climatic signal is recorded.

A Graph Theory Approach to Demographic Loop Analysis

A demographic analysis of the life-cycle graph can be used to quantify the separate contributions of different life-history types to the population growth rate. Loop analysis has been proposed (van Groenendael et al. 1994) as the appropriate method for partitioning the elasticity matrix to determine these contributions. However, in the analysis of complex demographic models it is difficult to derive the loops by simple inspection of the life-cycle graph. I show how graph theory can be used to describe a general and systematic procedure for deriving the loops from the structure of the life-cycle graph. I demonstrate that the concept of nullity (from graph theory) can be applied in this context to correctly determine the number of loops for any graph. Using examples from Campanula americana, Dipsacus sylvestris, and Caretta caretta, I illustrate the relationship of the loops to biologically relevant life-history contrasts. This relationship is crucial for the application of loop analysis to life-history evolution for the purpose of partitioning the separate effects on the population growth rate among different life-history components.

A GRAPH THEORY APPROACH TO DEMOGRAPHIC LOOP ANALYSIS

A demographic analysis of the life-cycle graph can be used to quantify the separate contributions of different life-history types to the population growth rate. Loop analysis has been proposed (van Groenendael et al. 1994) as the appropriate method for partitioning the elasticity matrix to determine these contributions. However, in the analysis of complex demographic models it is difficult to derive the loops by simple inspection of the life-cycle graph. I show how graph theory can be used to describe a general and systematic procedure for deriving the loops from the structure of the life-cycle graph. I demonstrate that the concept of nullity (from graph theory) can be applied in this context to correctly determine the number of loops for any graph. Using examples from Campanula americana, Dipsacus sylvestris, and Caretta caretta, I illustrate the relationship of the loops to biologically relevant life-history contrasts. This relationship is crucial for the application of loop analysis to life-history evolution for the purpose of partitioning the separate effects on the population growth rate among different life-history components.

The impact of some field boundary management practices on the development of Dipsacus fullonum L. flowering stems, and implications for conservation

Dipsacus fullonum ( Dipsacus sylvestris) is a native biennial, common in the UK agricultural landscape, providing floral resources for potential crop pollinators, natural enemies of cereal pests, and other insects. In north America, the plant has become established as an invasive alien, threatening to displace native species of sensitive conservation status. Surveys of farmland in Cambridgeshire, UK, over a three year period indicated that the plant's distribution along field boundaries rendered it prone to damage by routine boundary management practices. In experiments, some stems cut before flowering regrew but produced significantly fewer flowerheads than uncut plants; stems cut during or after flowering produced no new flowerheads. Seeds borne in flowerheads of plants cut during or immediately after flowering failed to germinate. Although the local persistence of D. fullonum did not appear to be threatened by routine management in this study, resulting loss of floral resources has implications for the plant's insect fauna. Flexibility in the timing of boundary management could alleviate potential negative effects on beneficial insects in UK agroecosystems. Knowledge of the suppression of seed production by appropriately timed stem-cutting might be incorporated into control programmes in systems where the plant is an invasive alien.

A Floral Ontogenetic Study in the Dipsacales

The floral ontogeny of five representative species (Lonicera periclymenum, Symphoricarpos albus, Centranthus ruber, Dipsacus sylvestris, and Knautia arvensis) of Dipsacales has been studied and compared with existing floral ontogenies in order to examine the unresolved systematic position of Dipsacales. The floral ontogeny of the species studied differs only in minor aspects. All inflorescences share a basic dichotomous branching pattern initiated in an acropetal direction. The flowers of Dipsacus and Knautia (Dipsacaceae) arise successively in contact parastichies and are grouped in heads. However, the earliest flowers in the heads of Dipsacus are initiated in pairs, making a connection with the other dipsacalean families possible. In Dipsacaceae an epicalyx with a mixed bract and bracteolar origin arises. The sepals arise as individual primordia in Lonicera and Symphoricarpos (Caprifoliaceae). In the other genera individual sepal primordia are not observed, but a sepaloid meristematic ring is formed instead. The petal primordia are initiated on a meristematic ringlike zone on the floral apex. A reductive trend is seen in the androecium. The number of stamens and/or their fertility is reduced from the adaxial to the abaxial part of the flower; however, the direction of the reduction can be reversed. The first step in gynoecium development is the initiation of a central depression in the floral apex. Individual carpel primordia are never observed. The gynoecia of Centranthus (Valerianaceae), Dipsacus, and Knautia are extremely reduced. Comparison of the floral ontogenies of Apiales, Asterales-Campanulales, and Dipsacales reveals a high degree of similarity.

Mechanisms Underlying the Suppression of Forb Seedling Emergence by Grass (Poa pratensis) Litter

We investigated the mechanism by which grass litter (dead Poa pratensis L. shoots) suppressed the emergence of seedlings of four old-field forbs (Centaurea nigra L., Dipsacus sylvestris Huds., Hypericum perfioratum L., Verbascum thapsus L.) by determining the effect of litter on their seed germination and shoot extension. When seeds were placed beneath litter (715 g m -2 ) that had been collected from an old-field, the germination of all species except Verbascum was reduced significantly by 26% to 41% compared to a no-litter control. When seeds were placed in plastic dishes containing a leachate solution made from litter (7 g dish -1 ), the germination of two species (i.e. Centaurea and Dipsacus) was reduced significantly by 10% to 34% compared to the distilled water control. When germinated seeds were placed beneath litter, the emergence of seedlings of all species was reduced significantly by 95% to 100% compared to a no-litter control. These results indicate that grass litter may suppress forb seedling emergence by reducing seed germination and (or) by preventing shoot extension and that these effects are species dependent.

Potential Interference Between a Threatened Endemic Thistle and an Invasive Nonnative Plant

Although the establishment of nonnative plants is recognized as a threat to native ecosystems, there are few documented examples of an invasive species directly influencing a rare native plant. The Eurasian biennial Dipsacus sylvestris (teasel) is invading the central New Mexico habitat of Cirsium vinaceum, an endemic thistle that is federally listed as threatened. We documented changes in teasel distribution and abundance between 1989 and 1993 that suggest the potential for direct interactions with the native thistle. We then compared habitat characteristics, germination behavior, and performance in greenhouse and field competition trials to evaluate the potential outcome of interference between these two species. There were no significant differences in measured habitat characteristics between sites supporting C. vinaceum and those with D. sylvestris. Dipsacus was better able to germinate in low light than the thistle, suggesting that D. sylvestris might invade C. vinaceum populations but that thistle recruitment would be unlikely in dense stands of the nonnative plants. In the greenhouse growth of C. vinaceum rosettes was significantly reduced by the presence of Dipsacus, but the invader was unaffected by the thistle; results of a short‐term field experiment were equivocal but suggestive of interference between the two. We suggest criteria for managers to use in determining whether invading species pose problems for specific rare native taxa, and we discuss the constraints on experimental work where protected taxa are involved.

Simple Methods for Calculating Age‐Based Life History Parameters for Stage‐Structured Populations

Stage—classified matrix models are important analytical and theoretical tools for the study of population dynamics; in particular, these models may be appropriate for populations in which survivorship and fecundity are dependent on size or developmental stage, populations in which the age of individuals is difficult to determine, and populations in which there are multiple types of newborns. Nevertheless, methods for analyzing the implications of a population's stage—transition matrix have been limited in comparison to methods available for age—structured models (life tables or Leslie matrices). In this paper we show that all of the standard age—based measures of life history traits can be derived from a stage—transition model. By decomposing the transition matrix into separate birth, survival, and fission matrices we derive simple, direct formulas for age—based life history traits such as the discrete survivorship function, lx, maternity function, fx, mean age at maturity, and net reproductive rate, Ro, and also population parameters, including the stable age distribution, age—specific reproductive value, and generation time. These provide a common set of parameters for comparing age—structured and stage—structured populations or comparing populations with differently structured life cycles. In addition, we define four measures of age and life—span that summarize the relationship between stage and age in a stage—structured population: age distribution and mean age of residence for each stage class, expected remaining life—span for individuals in each stage class, and total life—span conditional on reaching a given stage class. We illustrate the use of our methods to address specific ecological questions by applying them to several previously published demographic data sets. These questions include: (1) what are the demographic effects of crowding on the tropical palm Astrocaryum mexicanum?; (2) how important is the initial rosette size in determining life history of teasel, Dipsacus sylvestris?; and (3) how old are reproducing adults in a stage—classified population of pink lady's—slipper, Cypripedium acaule? Our results may also be useful for evaluating the adequacy of a given stage—transition model.

Seed Persistence in Soil and Seasonal Emergence in Plant Species from Different Habitats

(1) The extent to which plants form a persistent seed bank and the time of year at which seedlings arise from it both have a bearing on the establishment of vegetation after disturbance. These attributes were determined for seventy dicotyledons from a range of habitats by mixing freshly-collected seeds with the top 7.5 cm of soil confined in cylinders sunk in the ground, cultivating three times yearly, and recording emergence for 5 years. (2) In about one-third of the species, few seeds persisted for longer than a year and most seedlings emerged in the autumn of sowing (Sherardia arvensis*, Galium mollugo) or early in the following spring (Chaerophyllum temulentum, Pimpinella saxifraga, Agrimonia eupatoria, Tragopogon pratensis). (3) The remaining species formed a persistent seed bank in cultivated soil from which seedlings arose in each year for which the experiments continued. Some exhibited a consistent pattern of emergence entirely (Odontites verna, Linum catharticum) or mainly (Brassica nigra, Silene dioica) in spring, while others (Hyoscyamus niger, Erodium cicutarium, Amaranthus retroflexus) emerged in late spring and summer. Emergence of Arenaria serpyllifolia, Cerastium glomeratum and Anthriscus caucalis was mainly in early autumn, while that of Legousia hybrid began in autumn and continued into spring. (4) Other species showed no pronounced pattern of emergence in successive years. Although there was often a tendency for most seedlings to emerge in spring or autumn, some appeared throughout the growing season with flushes following soil disturbance. Included in this group were Barbarea vulgaris, Coronopus didymus, Ballota nigra and Dipsacus sylvestris. (5) There were consistent differences between species in the extent of immediate emergence, seed survival in disturbed soil and in the seasonal pattern of emergence. Seeds of annual weeds of arable land were all relatively long-lived, but otherwise there appeared to be little relationship between seed persistence and habitat. The results provide indications of the potential for regeneration by different species from the seed bank after disturbance of a plant community and of the times of year at which it is likely to take place.

Effects of Seed Size and Growth Form on Seedling Establishment of Six Monocarpic Perennial Plants

(1) Effects of seed size and seedling morphology on the establishment of six monocarpic perennials were examined in glasshouse experiments. Both withinand between-species comparisons of seed-size effects were made as seed weight varied by more than two orders of magnitude among species and by 3 to 20-fold within a species. Experiments were conducted in four ground-cover types: bare soil, litter cover, vegetated, and vegetated plus litter. (2) In vegetated cover, emergence of the two small-seeded species, Verbascum thapsus and Oenothera biennis, was significantly lower than in litter and bare soil. In contrast, emergence of the medium (Dacus carota and Dipsacus sylvestris) and large-seeded species (Tragopogon dubius and Arctium minus), was not significantly reduced in the presence of vegetation. Although the rate of emergence of all six species was significantly reduced in vegetated cover, there were no between species differences in seedling emergence rates in any cover type. (3) Relative growth rates of all six species were significantly lower in vegetated cover compared with litter and bare soil and the effect was greatest on the small-seeded species. At the end of the experiment, seedling weight in vegetated cover was positively correlated with seed weight. In non-competitive cover types (litter and bare soil), seedling weight was independent of initial seed weight. (4) Relative growth rates of seedlings in non-competitive cover types were inversely related to seed size. In bare soil and litter, the small-seeded species had relative growth rates twice those of the large-seeded species. In vegetated cover this pattern was reversed; the species with large seeds had the highest relative growth rates. (5) The growth form of a seedling did not have any effect on its probability of establishment in any cover type. Species with different growth forms and similar seed sizes had equal emergence, survival, and relative growth rates in all four cover types. (6) Within species differences in seed size had a significant effect on seedling growth in non-competitive cover, but had no effect on seedling growth in competitive cover. Thus, both withinand between-species differences in seed size had similar effects on seedling establishment success in different types of ground cover.

Quinacrine fluorescence analysis of the chromosomes of Dipsacus fullonum L. (Dipsacaceae)

Abstract Quinacrine fluorescence analysis of the chromosome complement of Dipsacus fullonum L. shows clear heterochromatic regions appearing as brightly fluorescent bands or clusters of fluorescent dots in most chromosomes. The resulting fluorescent pattern is chromosome specific.