| study of antibacterial activity and bacteriology of latex from asclepias syriaca l. | whole and fractionated latex of asclepias syriaca was tested for antimicrobial or growth-promoting activity with 16 genera and species of bacteria. latex and extracted fractions (distilled water, acetic acid, sodium bicarbonate, sulfuric acid, and ethyl ether) possessed no detectable antimicrobial activity. comparison of growth curves of selected bacteria incubated with serum and rubber fractions, as well as controls, revealed no detectable inhibition of growth, except for a slight inhibitory re ... | 1973 | 4790590 |
| characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed. | a cdna for a structurally variant acyl-acyl carrier protein (acp) desaturase was isolated from milkweed (asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1delta9)* and cis-vaccenic (18:1delta11) acids. extracts of escherichia coli that express the milkweed cdna catalyzed delta9 desaturation of acyl-acp substrates, and the recombinant enzyme exhibited seven- to ten-fold greater specificity for palmitoyl (16:0)-acp and 30-fold greater specificity for myristoyl (14:0)-acp than did know ... | 1997 | 9154992 |
| attraction of culex pipiens pipiens (diptera: culicidae) to flower volatiles. | methylene chloride extracts of flowers from 4 plants (common milkweed, asclepias syriaca l; ox-eye daisy, leucanthemum vulgare lamarck; canada goldenrod, solidago canadensis l.; and yarrow, achillea millefolium l.) were tested in a dual-port olfactometer for attractiveness to female northern house mosquitoes, culex pipiens pipiens l. fifty milligrams of extract was used for each test, which was equivalent to the amount of extract from flowers of 0.58 common milkweed inflorescences, 1.75 ox-eye d ... | 1999 | 10467780 |
| reactivity of hela tumoral cells under the in vitro action of some aromatic compounds from the phytomass. | the in vitro action of some natural polyphenolic preparations, extracted from the leaves of asclepias syriaca, upon the proteinosynthesis of hela cancerous cells and, implicitly, upon the development of hela cells cultures was investigated. the significant perturbation of proteic biogenesis, the inhibition of hela tumoral cells cultures development, as well as the existence of a dose--response relationship argue the behaviour of these products as in vitro active cytostatic agents. this character ... | 1998 | 11000870 |
| impact of bt corn pollen on monarch butterfly populations: a risk assessment. | a collaborative research effort by scientists in several states and in canada has produced information to develop a formal risk assessment of the impact of bt corn on monarch butterfly (danaus plexippus) populations. information was sought on the acute toxic effects of bt corn pollen and the degree to which monarch larvae would be exposed to toxic amounts of bt pollen on its host plant, the common milkweed, asclepias syriaca, found in and around cornfields. expression of cry proteins, the active ... | 2001 | 11559842 |
| preclinical qualitative evaluation of the antitumoral pharmacodynamic action of some natural polyphenolic biopreparations. | we have investigated the impact of polyas i and polyas ii polyphenolic biopreparations - specifically separated and purified from asclepias syriaca leaves, and characterized in vitro as cytotoxic and/or cytostatic agents - on the tumor generation process. a series of in vivo tests of their effect on the development of guerin t-8 lymphotropic epithelioma and walker 256 carcinosarcoma were conducted. in a first stage of preclinical trial we had used several tests meant to evaluate their antitumour ... | 2000 | 12413150 |
| preclinical trial of the antitumoral therapeutic effectiveness of some natural polyphenolic biopreparations. | we have assessed the antitumoral action of the polyas i and polyas ii vegetal polyphenolic biopreparations--separated and purified from asclepias syriaca leaves - in rats with various experimental tumoral lines. we studied the therapeutic effect of different doses on the tumor generation process and compared it with the experimental oncostatic action of several standard chemotherapeutic drugs of clinical use (thiotepa, methotrexate, melphalan and cyclophosphamide). in our experimental treatment ... | 2000 | 12413151 |
| metschnikowia vanudenii sp. nov. and metschnikowia lachancei sp. nov., from flowers and associated insects in north america. | two new species of the ascosporic yeast genus metschnikowia were isolated from nectaries and associated muscoid flies of flowers from the common milkweed (asclepias syriaca) in north america, and are described as metschnikowia vanudenii [type strain=pycc 4650(t)=cbs 9134(t)=nrrl y-27243(t)=uwo(ps) 86a4.1(t)] and metschnikowia lachancei [type strain=pycc 4605(t)=cbs 9131(t)=nrrl y-27242(t)=uwo(ps) 7asb2.3(t)]. as with the previously described metschnikowia gruessii, m. vanudenii has vegetative ce ... | 2003 | 13130066 |
| experimental and natural weed host-virus relations. | weeds, as alternative hosts of plant viruses and nutrient plants of virus vectors play important role in virus ecology and epidemiology. the aim of our study was to discover new weed-virus relations. therefore some weed species were mechanically inoculated with 28 viruses (strains or isolates) maintained in our glasshouse. different weed species with and without visible symptoms were collected from agro-, water ecosystems and wastelands of hungary between 1997 and 2003. virus infections were eva ... | 2004 | 15759395 |
| interspecific variation within the genus asclepias in response to herbivory by a phloem-feeding insect herbivore. | induced plant responses to leaf-chewing insects have been well studied, but considerably less is known about the effects of phloem-feedings insects on induction. in a set of laboratory experiments, we examined density-dependent induction by the milkweed-oleander aphid, aphis nerii, of putative defenses in four milkweed species (asclepias incarnata, asclepias syriaca, asclepias tuberosa, and asclepias viridis). we hypothesized that high aphid density would lead to increased cardenolide expression ... | 2007 | 17929096 |
| plant genotype shapes ant-aphid interactions: implications for community structure and indirect plant defense. | little is known about the mechanisms by which plant genotype shapes arthropod community structure. in a field experiment, we measured the effects of milkweed (asclepias syriaca) genotype and ants on milkweed arthropods. populations of the ant-tended aphid aphis asclepiadis and the untended aphid myzocallis asclepiadis varied eight- to 18-fold among milkweed genotypes, depending on aphid species and whether ants were present. there was no milkweed effect on predatory arthropods. ants increased ap ... | 2008 | 18419551 |
| coexistence of three specialist aphids on common milkweed, asclepias syriaca. | coexistence of host-specific herbivores on plants is believed to be governed by interspecific interactions, but few empirical studies have systematically unraveled these dynamics. we investigated the role of several factors in promoting coexistence among the aphids aphis nerii, aphis asclepiadis, and myzocallis asclepiadis that all specialize on common milkweed (asclepias syriaca). competitive exclusion is thought to occur when interspecific competition is stronger than intraspecific competition ... | 2008 | 18724729 |
| aerial reproductive structures of vascular plants as a microhabitat for myxomycetes. | this study explored the occurrence and distribution of myxomycete species on the aerial reproductive structures of vascular plants. eight species of vascular plants representing five families were sampled. the doubled rope climbing method was used to collect bark and cones from the canopy of pinus echinata. bark and aerial seed pods were gathered from cercis canadensis, follicles and stems from asclepias syriaca, dried composite inflorescences and stems from echinacea angustifolia, e. pallida, a ... | 2009 | 19537204 |
| comparative studies of herpetomonads and leishmanias : i. cultivation of herpetomonads from insects and plants. | nine strains of herpetomonads have been isolated in pure culture from eight varieties of insects, and three strains from two species of plants. four of the cultures were derived from latex-feeding insects (oncopeltus fasciatus, oncopeltus sp. ?, lygaeus kalmii) and three from latex plants (asclepias syriaca, asclepias nivea), two from mosquitoes (culex pipiens and anopheles quadrimaculatus), one from the house fly (musca domestica), and two from bluebottle flies. in addition impure cultures have ... | 1926 | 19869186 |
| comparative studies of herpetomonads and leishmanias : ii. differentiation of the organisms by serological reactions and fermentation tests. | serological reactions and fermentation tests have been employed in the present investigation as a means of differentiating various strains of herpetomonads from one another as well as from leishmanias. the twelve strains of herpetomonads isolated from insects and plants all proved to be serologically unrelated to any of the leishmanias, and were distinguishable from them by the manner in which they affected various carbohydrates. three of the strains of herpetomonads tested had been isolated fro ... | 1926 | 19869187 |
| investigation of some characteristics of polyhydroxy milkweed triglycerides and their acylated derivatives in relation to lubricity. | most industrial lubricants are derived from nonrenewable petroleum-based sources. as useful as these lubricants are, their unintended consequences are the pollution of the earth's environment as a result of the slow degradation of the spent materials. native seed oils, on the other hand, are renewable and are also biodegradable in the environment, but these oils often suffer a drawback in having lower thermal stability and a shorter shelf life because of the intrinsic -c-c- unsaturation in their ... | 2011 | 21428293 |
| building a model: developing genomic resources for common milkweed (asclepias syriaca) with low coverage genome sequencing. | abstract: background: milkweeds (asclepias l.) have been extensively investigated in diverse areas of evolutionary biology and ecology; however, there are few genetic resources available to facilitate and compliment these studies. this study explored how low coverage genome sequencing of the common milkweed (asclepias syriaca l.) could be useful in characterizing the genome of a plant without prior genomic information and for development of genomic resources as a step toward further developing a ... | 2011 | 21542930 |
| analysis and optimization of a synthetic milkweed floral attractant for mosquitoes. | a pentane extract of flowers of common milkweed, asclepias syriaca (asclepiadaceae), elicited significant orientation from both male and female culex pipiens in a dual-port flight olfactometer. analysis of the extract by gas chromatography-mass spectrometry revealed six major constituents in order of relative abundance: benzaldehyde, (e)-β-ocimene, phenylacetaldehyde, benzyl alcohol, nonanal, and (e)-2-nonenal. although not all were collected from the headspace profile of live flowers, a synthet ... | 2012 | 22711028 |
| field deposition of bt transgenic corn pollen: lethal effects on the monarch butterfly. | we present the first evidence that transgenic bacillus thuringiensis (bt) corn pollen naturally deposited on asclepias syriaca; common milkweed, in a corn field causes significant mortality of danaus plexippus l. (lepidoptera: danaidae) larvae. larvae feeding for 48 h on a. syriaca plants naturally dusted with pollen from bt corn plants suffered significantly higher rates of mortality at 48 h (20±3%) compared to larvae feeding on leaves with no pollen (3±3%), or feeding on leaves with non-bt pol ... | 2000 | 24595835 |
| incidence of ozone symptoms on vegetation within a national wildlife refuge in new jersey, usa. | during 1993-1996 and 2001-2003, we evaluated the percentage of plants (incidence) exhibiting ozone-induced foliar symptoms on vegetation within a national wildlife refuge located along the atlantic ocean coast of new jersey, usa. incidence varied among plant species and years. bioindicator plants most sensitive to ozone, across all years, included native common milkweed (asclepias syriaca) and wild grape (vitis spp.), as well as introduced tree-of-heaven (ailanthus altissima). less sensitive bio ... | 2006 | 16458398 |
| glyphosate and dicamba herbicide tank mixture effects on native plant and non-genetically engineered soybean seedlings. | crops engineered to contain genes for tolerance to multiple herbicides may be treated with several herbicides to manage weeds resistant to each herbicide. thus, nearby non-target plants may be subjected to increased exposure to several herbicides used in combination. of particular concern are native plants, as well as adjacent crops which have not been genetically engineered for tolerance to herbicides. we evaluated responses of seven species of native plants grown in a greenhouse and treated le ... | 2015 | 25821135 |
| self-pollination rate and floral-display size in asclepias syriaca (common milkweed) with regard to floral-visitor taxa. | animals fertilize thousands of angiosperm species whose floral-display sizes can significantly influence pollinator behavior and plant reproductive success. many studies have measured the interactions among pollinator behavior, floral-display size, and plant reproductive success, but few studies have been able to separate the effects of pollinator behavior and post-pollination processes on angiosperm sexual reproduction. in this study, we utilized the highly self-incompatible pollinium-pollinati ... | 2014 | 24958132 |
| the turnover of milkweed pollinia on bumble bees, and implications for outcrossing. | bumble bees (bombus spp.) picked up a pollen packet (pollinium) of milkweed (asclepias syriaca l.) every 2-5 h, usually more rapidly on their feet than on their mouthparts. pollinia were retained an average of slightly over one day on the mouthparts and one-quarter day on the feet. this long retention period enhances the possibility of outcrossing in this largely or completely self-incompatible species. although many more pollinia were carried on the feet, the longer retention of those on the mo ... | 1982 | 28311108 |
| the influence of eastern north american autumnal migrant monarch butterflies (danaus plexippus l.) on continuously breeding resident monarch populations in southern florida. | in florida, the eastern north american population of the monarch butterfly exhibits geographic variability in population structure and dynamics. this includes the occurrence of migrants throughout the peninsula during the autumnal migration, occasional overwintering clusters that form along the gulf coast, remigrants from mexico that breed in north-central florida during the spring, and what have been assumed to be year-round, resident breeding populations in southern florida. the work reported ... | 2009 | 19579046 |
| induced defences alter the strength and direction of natural selection on reproductive traits in common milkweed. | evolutionary biologists have long sought to understand the ecological processes that generate plant reproductive diversity. recent evidence indicates that constitutive antiherbivore defences can alter natural selection on reproductive traits, but it is unclear whether induced defences will have the same effect and whether reduced foliar damage in defended plants is the cause of this pattern. in a factorial field experiment using common milkweed, asclepias syriaca l., we induced plant defences us ... | 2017 | 28133846 |
| plant chemical defense indirectly mediates aphid performance via interactions with tending ants. | the benefits of mutualistic interactions are often highly context dependent. we studied the interaction between the milkweed aphid aphis asclepiadis and a tending ant, formica podzolica. although this interaction is generally considered beneficial, variation in plant genotype may alter it from mutualistic to antagonistic. here we link the shift in strength and relative benefit of the ant-aphid interaction to plant genotypic variation in the production of cardenolides, a class of toxic defensive ... | 2017 | 28060424 |
| predators modify biogeographic constraints on species distributions in an insect metacommunity. | theory describing the positive effects of patch size and connectivity on diversity in fragmented systems has stimulated a large body of empirical work, yet predicting when and how local species interactions mediate these responses remains challenging. we used insects that specialize on milkweed plants as a model metacommunity to investigate how local predation alters the effects of biogeographic constraints on species distributions. species-specific dispersal ability and susceptibility to predat ... | 2017 | 28036097 |
| the complete chloroplast genome sequence of an important medicinal plant cynanchum wilfordii (maxim.) hemsl. (apocynaceae). | cynanchum wilfordii (maxim.) hemsl. is a traditional medicinal herb belonging to the asclepiadoideae subfamily, whose dried roots have been used as traditional medicine in asia. the complete chloroplast genome of c. wilfordii was generated by de novo assembly using the small amount of whole genome sequencing data. the chloroplast genome of c. wilfordii was 161 241 bp long, composed of large single copy region (91 995 bp), small single copy region (19 930 bp) and a pair of inverted repeat regions ... | 2016 | 26358391 |
| evolution of plant growth and defense in a continental introduction. | substantial research has addressed adaptation of nonnative biota to novel environments, yet surprisingly little work has integrated population genetic structure and the mechanisms underlying phenotypic differentiation in ecologically important traits. we report on studies of the common milkweed asclepias syriaca, which was introduced from north america to europe over the past 400 years and which lacks most of its specialized herbivores in the introduced range. using 10 populations from each cont ... | 2015 | 26098351 |
| uptake and effects of six rare earth elements (rees) on selected native and crop species growing in contaminated soils. | rare earth elements (rees) have become increasingly important metals used in modern technology. processes including mining, oil refining, discarding of obsolete equipment containing rees, and the use of ree-containing phosphate fertilizers may increase the likelihood of environmental contamination. however, there is a scarcity of information on the toxicity and accumulation of these metals to terrestrial primary producers in contaminated soils. the objective of this work was to assess the phytot ... | 2015 | 26076480 |
| intragenomic polymorphisms among high-copy loci: a genus-wide study of nuclear ribosomal dna in asclepias (apocynaceae). | despite knowledge that concerted evolution of high-copy loci is often imperfect, studies that investigate the extent of intragenomic polymorphisms and comparisons across a large number of species are rarely made. we present a bioinformatic pipeline for characterizing polymorphisms within an individual among copies of a high-copy locus. results are presented for nuclear ribosomal dna (nrdna) across the milkweed genus, asclepias. the 18s-26s portion of the nrdna cistron of asclepias syriaca served ... | 2015 | 25653903 |
| hyb-seq: combining target enrichment and genome skimming for plant phylogenomics. | | 2014 | 25225629 |
| factors contributing to the recalcitrance of herbaceous dicotyledons (forbs) to enzymatic deconstruction. | many different feedstocks are under consideration for the practical production of biofuels from lignocellulosic materials. the best choice under any particular combination of economic, agronomic, and environmental conditions depends on multiple factors. the use of old fields, restored prairie, or marginal lands to grow biofuel feedstocks offers several potential benefits including minimal agronomic inputs, reduced competition with food production, and high biodiversity. however, a major componen ... | 2014 | 24708722 |
| genetic variation in plant volatile emission does not result in differential attraction of natural enemies in the field. | volatile organic chemical (voc) emission by plants may serve as an adaptive plant defense by attracting the natural enemies of herbivores. for plant voc emission to evolve as an adaptive defense, plants must show genetic variability for the trait. to date, such variability has been investigated primarily in agricultural systems, yet relatively little is known about genetic variation in vocs emitted by natural populations of native plants. here, we investigate intraspecific variation in constitut ... | 2014 | 24096739 |
| horizontal transfer of dna from the mitochondrial to the plastid genome and its subsequent evolution in milkweeds (apocynaceae). | horizontal gene transfer (hgt) of dna from the plastid to the nuclear and mitochondrial genomes of higher plants is a common phenomenon; however, plastid genomes (plastomes) are highly conserved and have generally been regarded as impervious to hgt. we sequenced the 158 kb plastome and the 690 kb mitochondrial genome of common milkweed (asclepias syriaca [apocynaceae]) and found evidence of intracellular hgt for a 2.4-kb segment of mitochondrial dna to the rps2-rpoc2 intergenic spacer of the pla ... | 2013 | 24029811 |
| rare earth elements (rees): effects on germination and growth of selected crop and native plant species. | the phytotoxicity of rare earth elements (rees) is still poorly understood. the exposure-response relationships of three native canadian plant species (common milkweed, asclepias syriaca l., showy ticktrefoil, desmodium canadense (l.) dc. and switchgrass, panicum virgatum l.) and two commonly used crop species (radish, raphanus sativus l., and tomato, solanum lycopersicum l.) to the rees lanthanum (la), yttrium (y) and cerium (ce) were tested. in separate experiments, seven to eight doses of eac ... | 2014 | 23978671 |
| a genetically-based latitudinal cline in the emission of herbivore-induced plant volatile organic compounds. | the existence of predictable latitudinal variation in plant defense against herbivores remains controversial. a prevailing view holds that higher levels of plant defense evolve at low latitudes compared to high latitudes as an adaptive plant response to higher herbivore pressure on low-latitude plants. to date, this prediction has not been examined with respect to volatile organic compounds (vocs) that many plants emit, often thus attracting the natural enemies of herbivores. here, we compared g ... | 2013 | 23888386 |
| spectroscopic sensitivity of real-time, rapidly induced phytochemical change in response to damage. | an ecological consequence of plant-herbivore interactions is the phytochemical induction of defenses in response to insect damage. here, we used reflectance spectroscopy to characterize the foliar induction profile of cardenolides in asclepias syriaca in response to damage, tracked in vivo changes and examined the influence of multiple plant traits on cardenolide concentrations. foliar cardenolide concentrations were measured at specific time points following damage to capture their induction pr ... | 2013 | 23384059 |
| identification of triterpenes from milkweed (asclepias syriaca). | the chloroform extract of asclepias syriaca stem were investigated. three triterpenes were isolated by tlc, vlc, and preparative chromatography, and their structures established by one and two-dimensional nmr spectroscopy. lupenyl acetate has been isolated for the first time from a. syriaca; this is thefirst representative of a triterpene bearing a lupane skeleton in this species. in addition, alpha-amyrin acetate and alpha-amyrin butyrate were isolated. | 2012 | 23074892 |
| attenuation of the jasmonate burst, plant defensive traits, and resistance to specialist monarch caterpillars on shaded common milkweed (asclepias syriaca). | plant responses to herbivory and light competition are often in opposing directions, posing a potential conflict for plants experiencing both stresses. for sun-adapted species, growing in shade typically makes plants more constitutively susceptible to herbivores via reduced structural and chemical resistance traits. nonetheless, the impact of light environment on induced resistance has been less well-studied, especially in field experiments that link physiological mechanisms to ecological outcom ... | 2012 | 22661306 |
| cytotoxic cardiac glycosides and other compounds from asclepias syriaca. | phytochemical investigation of the dried biomass of asclepias syriaca afforded five new compounds (1-5), along with 19 known structures. overall, the secondary metabolites isolated and identified from this plant showed a wide structural diversity including pentacyclic triterpenes, cardiac glycosides, flavonoid glycosides, lignans, a phenylethanoid, and a glycosylated megastigmane. in addition, the isolates were tested against the cancer breast cell line hs578t, and those showing ic(50) values lo ... | 2012 | 22316168 |
| isolation and characterization of microsatellite loci in the common milkweed, asclepias syriaca (apocynaceae). | microsatellite primers were developed for the common milkweed, asclepias syriaca l., to assist in genet identification and the analysis of spatial genetic structure. | 2010 | 21622436 |
| evolution of specialization: a phylogenetic study of host range in the red milkweed beetle (tetraopes tetraophthalmus). | specialization is common in most lineages of insect herbivores, one of the most diverse groups of organisms on earth. to address how and why specialization is maintained over evolutionary time, we hypothesized that plant defense and other ecological attributes of potential host plants would predict the performance of a specialist root-feeding herbivore (the red milkweed beetle, tetraopes tetraophthalmus). using a comparative phylogenetic and functional trait approach, we assessed the determinant ... | 2011 | 21597250 |
| does polyembryony confer a competitive advantage to the invasive perennial vine vincetoxicum rossicum (apocynaceae)? | determining which traits may allow some introduced plant species to become invasive in their new environment continues to be a key question in invasion biology. vincetoxicum rossicum is an invasive, perennial vine colonizing natural and seminatural habitats primarily in the northeastern united states and southeastern canada. more than half its seeds exhibit polyembryony, a relatively uncommon condition in which a single seed produces multiple seedlings. for evaluating the potential consequences ... | 2010 | 21622385 |
| study on the seed production and germination dynamic of common milkweed (asclepias syriaca l.). | the common milkweed causes considerable damages on the agricultural and nature conservation areas. the area occupied by this weed is continuously bigger. the common milkweed is spread over north-america between the 35th and 50th degree of western latitude and 60th 103rd degree of longitude. millions of hectares are polluted by this weed in the united states. important is its spread also in asia (iraq), in europe (carpathian basin, poland, bulgaria, switzerland, france, austria, germany), as well ... | 2008 | 19226850 |
| acylated-oxypregnane glycosides from the roots of asclepias syriaca. | twenty new pregnane glycosides were obtained from the roots of asclepias syriaca l. (asclepiadaceae). these glycosides were confirmed to contain ikemagenin, 12-o-nicotinoyllineolon, 5alpha,6-dihydroikemagenin, and 12-o-tigloylisolineolon, as their aglycones, using both spectroscopic and chemical methods. | 2009 | 19182408 |
| impairment of leaf photosynthesis after insect herbivory or mechanical injury on common milkweed, asclepias syriaca. | insect herbivory has variable consequences on plant physiology, growth, and reproduction. in some plants, herbivory reduces photosynthetic rate (pn) activity on remaining tissue of injured leaves. we sought to better understand the influence of leaf injury on pn of common milkweed, asclepias syriaca (asclepiadaceae), leaves. initially, we tested whether pn reductions occurred after insect herbivory or mechanical injury. we also (1) examined the duration of photosynthetic recovery, (2) compared m ... | 2008 | 19036214 |
| effects of maternal age and environment on offspring vital rates in the oleander aphid (hemiptera: aphididae). | maternal effects have the potential to affect population dynamics and evolution. to affect population dynamics, maternal effects must influence offspring vital rates (birth, death, or movement). here, we explore the magnitude of nongenetic maternal influence on the vital rates of an insect herbivore and explore predictability of maternal effects with reference to published studies. we experimentally studied the effects of maternal age, host plant species (two asclepias spp.), and density on offs ... | 2007 | 17716483 |
| seasonal and diurnal gas exchange differences in ozone-sensitive common milkweed (asclepias syriaca l.) in relation to ozone uptake. | stomatal conductance and net photosynthesis of common milkweed (asclepias syriaca l.) plants in two different soil moisture regimes were directly quantified and subsequently modeled over an entire growing season. direct measurements captured the dynamic response of stomatal conductance to changing environmental conditions throughout the day, as well as declining gas exchange and carbon assimilation throughout the growth period beyond an early summer maximum. this phenomenon was observed in plant ... | 2008 | 17655989 |
| monarch butterfly oviposition on swallow-worts (vincetoxicum spp.). | as black swallow-wort, vincetoxicum nigrum l. moench, and pale swallow-wort, v. rossicum (kleopow) barbar., spread throughout the northeastern united states and southern canada, there is concern about the impact of these invasive plants on populations of the native north american monarch butterfly danaus plexippus l. recent laboratory studies in new york and ontario, canada, have found little or no oviposition by monarch butterflies on the two vincetoxicum species. in rhode island, we found 10.5 ... | 2007 | 17540075 |
| changes in landscape structure decrease mortality during migration. | i examined the dispersal of the red milkweed beetle, tetraopes tetraophthalmus, among patches of its host plant, common milkweed, asclepias syriaca. over a 5-year period, the number of patches in a landscape and their mean size increased, while the distance between patches decreased. over the same period the proportion of beetles dispersing between patches increased from 0.48 to 0.62. estimates from the virtual migration model showed that mean migration distance decreased from 158 to 72 m for ma ... | 2006 | 16858584 |
| 4-hydroxy-3-methoxycinnamate esters of milkweed oil: synthesis and characterization. | the common milkweed (asclepias syriaca l.) is a new industrial crop. its seed oil (tag) is highly polyunsaturated. in the search for novel applications for milkweed seed oil, the olefinic groups in the tag were oxidized to polyhydroxy tag via epoxidation and subsequent epoxy ring-opening reactions. these polyhydroxy tag exhibit unique industrially desirable emulsoid properties in water. esterification of the secondary polyhydroxy functionalities of the tag derivatives of the oil with trans-4-hyd ... | 2005 | 16459931 |
| field responses of prunus serotina and asclepias syriaca to ozone around southern lake michigan. | higher ozone concentrations east of southern lake michigan compared to west of the lake were used to test hypotheses about injury and growth effects on two plant species. we measured approximately 1000 black cherry trees and over 3000 milkweed stems from 1999 to 2001 for this purpose. black cherry branch elongation and milkweed growth and pod formation were significantly higher west of lake michigan while ozone injury was greater east of lake michigan. using classification and regression tree (c ... | 2006 | 16343714 |
| variation in resource limitation of plant reproduction influences natural selection on floral traits of asclepias syriaca. | the availability of both pollen and resources can influence natural selection on floral traits, but their relative importance in shaping floral evolution is unclear. we experimentally manipulated pollinator and resource (fertilizer and water) availability in the perennial wildflower asclepias syriaca l. nine floral traits, one male fitness component (number of pollinia removed), and two female fitness components (number of pollinia inserted and number of fruits initiated) were measured for plant ... | 2005 | 16028094 |
| use of bioindicators and passive sampling devices to evaluate ambient ozone concentrations in north central pennsylvania. | ambient concentrations of tropospheric ozone and ozone-induced injury to black cherry (prunus serotina) and common milkweed (asclepias syriaca) were determined in north central pennsylvania from 29 may to 5 september 2000 and from 28 may to 18 september 2001. ogawa passive ozone samplers were utilized within openings at 15 forested sites of which six were co-located with teco model 49 continuous ozone monitors. a significant positive correlation was observed between the ogawa passive samplers an ... | 2003 | 12804829 |
| synthesis, rheological characterization, and constitutive modeling of polyhydroxy triglycerides derived from milkweed oil. | asclepias syriaca l., the common milkweed, is a new industrial crop. the seed contains about 20-30 wt % of a highly unsaturated oil having unusual fatty acids. exploring value-added products from the oil, milkweed triglycerides have been oxidized by in situ performic acid to the polyoxirane and polyhydroxy triglycerides (phtg). the rheological properties of milkweed phtg were characterized in various shear flows. milkweed phtg displayed nonlinear viscoelastic behavior at applied strains greater ... | 2002 | 12009989 |
| construction cost and invasive potential: comparing lythrum salicaria (lythraceae) with co-occurring native species along pond banks. | lythrum salicaria (purple loosestrife) is a nonindigenous invasive species characterized by prolific growth and abundance in marshy and riparian habitats across north america. given its invasive success, we hypothesized this species may require less energy and/or use energy more efficiently for biomass construction than co-occurring noninvasive plant species. we measured leaf construction cost (cc), leaf mass per unit area (lma), and leaf organic nitrogen and carbon content of l. salicaria and t ... | 2001 | 21669658 |
| kaempferol and its glycosides in the seeds hair of asclepias syriaca l. | the following flavonoid compounds have been isolated and identified from the seeds hair of asclepias syriaca l.: kaempferol, kaempferol 3-o-beta-galactopyranoside, kaempferol 3-o-beta-xylopyranosyl (1 --> 2)-beta-galactopyranoside, kaempferol 3-o-beta-glucopyranosyl (1 --> 2)-beta-galactopyranoside, kaempferol 3-o-alpha-rhamnopyranosyl (1 --> 2)-beta-galactopyranoside. their structures were established by acid hydrolysis, h2o2 oxidation and spectral analysis (uv, 1h, 3c nmr, ms). | 2013 | 11712739 |
| kaempferol, isorhamnetin and their glycosides in the flowers of asclepias syriaca l. | the following flavonoid compounds have been isolated and identified from the flowers of asclepias svriaca l.: kaempferol, kaempferol 7-o-beta-glucoside, kaempferol 3-o-beta-galactopyranoside, kaempferol 3-o-beta-xylopyranosyl (1-->2)-beta-galactopyranoside, kaempferol 3-o-beta-glucopyranosyl (1-->2)-beta-galactopyranoside, isorhamnetin, isorhamnetin 7-o-beta-glucoside, isorhamnetin 3-o-beta-galactoside and isorhamnetin 3-o-beta-xylopyranosyl (1-->2)-beta-galactopyranoside. their structures were ... | 2016 | 11693731 |
| a 13-week comparison of passive and continuous ozone monitors at forested sites in north-central pennsylvania. | ogawa passive o3 samplers were used in a 13-week study (june 1-september 1, 1999) involving 11 forested and mountaintop sites in north-central pennsylvania. four of the sites were collocated with teco model 49 o3 analyzers. a significant correlation (p < 0.0001) was found for 24-hr average weekly o3 concentrations between the two methodologies at the four sites with collocated monitors. as expected, there were positive relationships between increasing elevation of the sites and increasing o3 con ... | 2001 | 11575881 |
| quercetin and its glycosides in the flowers of asclepias syriaca l. | the following flavonoid compounds have been isolated and identified from the flowers of asclepiac syriaca l.: quercetin and its glycosides: 7-o-galactoside, 7-o-glucoside, 3-o-beta-d-xylopyranoside(1-->2) beta-d-galactoside and 3-o-beta-d-glucopyranoside(1-->2) beta-d-galactoside. their structures were established by acid and enzymatic hydrolysis or h2o2 oxidation as well as spectral analysis (uv, 1h and 13c nmr). | 2013 | 11126623 |
| qualitative and quantitative analysis of phenolic acids in asclepias syriaca l. | tlc and hplc was applied to qualitative and quantitative determination of phenolic acids free and liberated by acid and alkaline hydrolysis in common milkweed. the presence of phenolic acids, namely p-hydroxybenzoic, p-coumaric, protocatechuic and caffeic acids, was confirmed in the leaves and flowers. moreover, the flowers contained gallic acid, and the leaves contained alpha-resorcylic, vanilic and chlorogenic acids. conjugated forms of phenolic acids predominate in the plant. they hydrolyse m ... | 2012 | 10846801 |
| the potential for and constraints on the evolution of compensatory ability in asclepias syriaca. | to investigate the potential for and constraints on the evolution of compensatory ability, we performed a greenhouse experiment using asclepias syriaca in which foliar damage and soil nutrient concentration were manipulated. under low nutrient conditions, significant genetic variation was detected for allocation patterns and for compensatory ability. furthermore, resource allocation to storage was positively, genetically correlated both with compensatory ability and biomass when damaged, the las ... | 2000 | 28308287 |
| population density and area: the role of between- and within-patch processes. | the relationship between population density and the size of host plant patches was investigated for the red milkweed beetle tetraopestetraophthalmus inhabiting unmanipulated patches of asclepias syriaca. the resource concentration hypothesis proposes that density-area patterns, specifically that of increasing herbivore density with patch size, are primarily a function of movement between host plant patches. this research investigated the degree to which movement accounted for density-area patter ... | 1997 | 28307246 |
| effect of elevated co2 on interactions betwe en the western flower thrips, frankliniella occidentalis (thysanoptera: thripidae) and the common milkweed, asclepias syriaca. | we measured the effect of elevated co2 on populations of the western flower thrips, frankliniella occidentalis and on the amount of leaf damage inflicted by the thrips to one of its host plants, the common milkweed, asclepias syriaca. plants grown at elevated co2 had significantly greater aboveground biomass and c:n ratios, and significantly reduced percentage nitrogen. the number of thrips per plant was not affected by co2 treatment, but the density of thrips (numbers per gram aboveground bioma ... | 1997 | 28307181 |
| stochastic prey arrivals and crab spider giving-up times: simulations of spider performance using two simple "rules of thumb". | we compared the patch-choice performances of an ambush predator, the crab spider misumena vatia (thomisidae) hunting on common milkweed asclepias syriaca (asclepiadaceae) umbles, with two stochastic rule-of-thumb simulation models: one that employed a threshold giving-up time and one that assumed a fixed probability of moving. adult female misumena were placed on milkweed plants with three umbels, each with markedly different numbers of flower-seeking prey. using a variety of visitation regimes ... | 1989 | 28312185 |
| cardenolide fingerprint of monarch butterflies reared on common milkweed,asclepias syriaca l. | monarch butterfly,danaus plexippus (l.), larvae were collected during august 1983 from the common milkweed,asclepias syriaca l., across its extensive north american range from north dakota, east to vermont, and south to virginia. this confirms that the late summer distribution of breeding monarchs in eastern north america coincides with the range of this extremely abundant milkweed resource. plant cardenolide concentrations, assayed by spectrophotometry in 158 samples from 27 collection sites, w ... | 1989 | 24271887 |
| cardenolide connection between overwintering monarch butterflies from mexico and their larval food plant,asclepias syriaca. | the majority (85%) of 394 monarch butterflies sampled from overwintering sites in mexico contain the same epoxy cardenolide glycosides, including most conspicuously a novel polar glycoside with a single genin-sugar bridge (aspecioside), as occur in the milkweedsasclepias speciosa anda. syriaca. this cardenolide commonality was established by isolating aspecioside and syriobioside from the wings of overwintering monarchs and the two plant species, and comparing chromatographie and nmr spectrometr ... | 1986 | 24307053 |
| propagule size, dispersal ability, and seedling performance in asclepias syriaca. | using the propagules of common milkweed (asclepias syriaca l.) we tested the predictions that decreasing size may increase dispersal ability, but also decrease the probability of seedling success, of wind-dispersed seeds. in 1982 and 1983 we released seeds from four milkweed clones at two heights in an open field and measured their dispersal distances. in the laboratory we measured falling times in a dead air space, seed mass and area, and coma mass and length of the same seeds. the seeds were l ... | 1985 | 28311571 |
| cis-polyisoprene synthesis in guayule plants (parthenium argentatum gray) exposed to low, nonfreezing temperatures. | exposure of guayule plants (parthenium argentatum gray) to 6 months of a night temperature of 7 degrees c results in a 2-fold stimulation of cis-polyisoprene (rubber) formation over that of control plants exposed to 21 to 24 degrees c night temperature. control and cold-treated plants contained 2.18% and 5.69% rubber, respectively. examination of the stem apices by transmission electron microscopy showed extensive formation of rubber particles in the cold-treated plants compared to the control p ... | 1984 | 16663456 |
| contributions of diurnal and nocturnal insects to the pollination of common milkweed (asclepias syriaca l.) in a pollen-limited system. | milkweed (asclepias syriaca l.: asclepiadaceae) flowers exposed only to diurnal pollinators (primarily bumble bees, bombus spp.) matured about eight times as many pods as did flowers exposed only to nocturnal visitors (moths). rates of pollinaria removal and pollinia insertion were similarly higher during the day than at night. moths deposited a much lower proportion of their pollinia in stigmatic chambers (one-fifth) than did diurnal pollinators. in spite of the poor service provided by nocturn ... | 1983 | 28310486 |
| seed predation and patterns of fruit production in asclepias syriaca l. | seed predation in relation to patterns of pod (and seed) distribution was examined in five samples of the common milkweed (asclepias syriaca l.), in tests of the "resource-concentration" effect both within- and beween-plants. the proportion of pods in a cluster that were attacked, particularly by the weevil rhyssomatus lineaticollis, was not consistently related to the number of pods contained in a cluster, the frequency of cluster sizes in a population, or the variance of cluster sizes on a ste ... | 1983 | 28310260 |
| the detection of cells with a laticifer-like metabolism in asclepias syriaca l. suspension cultures. | plant cell suspension cultures of asclepias syriaca l. are morphologically homogeneous, that is, most cells in a suspension population are thin-walled, parenchyma-like cells. however, metabolic specialization of certain cells may occur in culture without morphological specialization. this study shows that a small number of suspension cells may synthesize secondary metabolites normally synthesized by a secretory cell, the non-articulated laticifer. the laticifer cell is an elongate, non-septate c ... | 1983 | 24257983 |
| aging effect on nectar production in two clones of asclepias syriaca. | in common milkweed (asclepias syriaca), flower nectar volumes, concentration and sugar production varied according to the age of the sampled blossoms. in individual blossoms, nectar production peaked daily at 0800 hr. peak production during the life of the flower occurred on the second day of flowering, 50 h after anthesis, and nectar production ceased after 120 h. the amount and quality of nectar were affected by microclimatic conditions and varied between clones. however, the same secretory pa ... | 1983 | 28310779 |
| allelopathic properties of α-terthienyl and phenylheptatriyne, naturally occurring compounds from species of asteraceae. | alpha-terthienyl (α-t), a naturally occurring polyacetylene derivative from roots oftagetes erecta l., and phenylheptatriyne (pht), from leaves ofbidens pilosa l., were tested as possible allelopathic agents against four seedling species (asclepias syriaca l.,chenopodium album l.,phleum pratense l.,trifolium pratense l.).asclepias was the most sensitive of the species. allelopathic activity was enhanced in the presence of sunlight or sources of near-uv, with lc50s fora. syriaca of 0.15 ppm and 0 ... | 1982 | 24415251 |
| limited dispersal and its effect on population structure in the milkweed beetle tetraopes tetraophthalmus. | the movement patterns of adult milkweed beetles, tetraopes tetraphthalmus, were monitored via a mark-recapture technique. movement or dispersal patterns were studied in two natural populations, one in which the host plant, asclepias syriaca, was nearly continuously distributed over a 250×90 m area and another where asclepias was distributed in 17 small discrete patches. in both populations dispersal distances resulting from the flight patterns of the adult beetles were quite short, averaging les ... | 1981 | 28310321 |
| nectar parasitism of asclepias syriaca by ants: effect on nectar levels, pollinia insertion, pollinaria removal and pod production. | milkweed (asclepias syriaca l.) umbels and stems attended by ants (lasius neoniger emery and tapinoma sessile (say)) initiated significantly fewer pods and showed a trend to produce fewer mature pods than did umbels and stems not attended by ants. since similar numbers of pollinia were inserted in ant-attended flowers, we hypothesize that ant-excluded flowers obtain more pollinia from other clones than do ant-attended flowers of this normally non-selfing species. if pollinators from other clones ... | 1981 | 28309047 |
| homologies of the n-terminal sequences of asclepains and papain. | sequences to residue 21 have been determined for the two asclepains, cysteinyl proteases isolated from milkweed (asclepias syriaca l.). these were compared with the sequence for papain, and extensive homology was found. | 1980 | 6998501 |
| multiple forms of the asclepains. cysteinyl proteases from milkweed. | two groups of asclepains (ec 3.4.22.7) isolated from the latex of asclepias syriaca l. (milkweed) were each separated into five homogeneous enzymes. the members of each group are of similar amino acid composition, and leucine is the common n-terminal residue. michaelis values are reported for each of the component cysteinyl proteases of milkweek latex, and are compared with those of analogous enzymes from other plant sources. the asclepains all catalysed the hydrolysis of insulin b chain to yiel ... | 1980 | 6988008 |
| purification and preliminary characterization of two asclepains from the latex of asclepias syriaca l. (milkweed). | two groups of asclepains have been isolated from asclepias syriaca l. (milk-weed) latex and a representative of each has been purified. asclepains a3 and b5 are homogeneous proteins with molecular weights of 23 000 and 21 000, respectively. both require a reducing and chelating agent for maximum activity and hydrolyze ester, amide and peptide bonds. the optimum ph for hydrolysis of casein is 7.5 to 8.5 for asclepain a3 and 7.0 to 7.5 for asclepain b5. both enzymes are autolytic when active and a ... | 1979 | 36921 |
| some consequences for a parasitic herbivore, the milkweed longhorn beetle, tetraopes tetrophthalmus, of a host-plant shift from asdepias syriaca to a. verticillata. | the impact of differences in host plants on individuals and populations of insect herbivores was investigated using the milkweed longhorn beetle, tetraopes tetrophthalmus (forster), larvae of which feed parasitically on host rhizomes. one host, asclepias syriaca l., was larger in stem and rhizome diameter and grew in cooler soil than the other host, a. verticillata l. the major effects on beetles were retarded phenology at the cooler site and reduced size on the smaller host. reduced size of bee ... | 1976 | 28309199 |
| natural food requirements of the large milkweed bug,oncopeltus fasciatus (hemiptera: lygaeidae), and their relation to gregariousness and host plant morphology. | the life ofoncopeltus fasciatus centers on the seeds of milkweeds (asclepiadaceae,asclepias syriaca in this study). adults reproduce prolifically on these seeds, but they engage in only half as much copulation and lay only a few eggs when fed milkweed buds and flowers instead. they can not maintain body weight on a diet of just vegetative plants. vegetative shoots support only slow growth and produce adults only in certain circumstances.seeds are often inaccessible to nymphs in the three younges ... | 1976 | 28309260 |
| an ultrasturctural study of the trypanosomatid, phytomonas elmassiani, from the milkweed, asclepias syriaca. | | 1971 | 4333536 |
| | the feeding behaviour of oncopeltus fasciatus has been investigated. exploration of food materials is performed by means of watery saliva which is secreted onto surfaces of substrates and sucked back again. histological tests indicate that the animal preferably pierces the conducting system of the vicia faba plant. oncopeltus fasciatus secretes sheath material which coagulates and forms a lining to the path of the stylets during plant feeding. feeding on seeds (asclepias syriaca and helianthus a ... | 1969 | 28308908 |
| development of oil in the seed of asclepias syriaca l. | | 1961 | 13715752 |
| uzarigenin and desglucouzarin from asclepias syriaca l. | | 1961 | 13687937 |
| [an aspect of the possibilities of the use of gum elastic from "asclepias syriaca l.", of spanish production]. | | 2008 | 13706922 |
| [an interesting vegetal species as a rubber producing source, asclepias syriaca l]. | | 1949 | 15398554 |