| evaluation of anti-inflammatory activity of essential oils from two asteraceae species. | the essential oils from two asteraceae species, porophyllum ruderale (pr) and conyza bonariensis (cb) were screened for anti-inflammatory activity in the mouse model of pleurisy induced by zymosan (500 microg/cavity) and lipopolysaccharide (lps) (250 ng/cavity). the main monoterpene constituents of each oil, beta-myrcene (in pr) and limonene (in cb), were tested in the lps-induced pleurisy model and assayed also for immunoregulatory activity by measurement of the inhibition of no and production ... | 2003 | 12967039 |
| resistance to the herbicide paraquat and increased tolerance to photoinhibition are not correlated in several weed species. | photoinhibition was examined in paraquat-resistant and paraquat-susceptible biotypes of hordeum glaucum steud., hordeum leporinum link., arctotheca calendula (l.) levyns., and conyza bonariensis (l.) cronq. plants were photoinhibited at low temperature, and the extent of photoinhibition determined by o(2) evolution and 77 k fluorescence. no difference in the degree of photoinhibition was detected between paraquat-resistant and paraquat-susceptible biotypes for any of the species examined. c. bon ... | 1991 | 16668172 |
| review of potential environmental impacts of transgenic glyphosate-resistant soybean in brazil. | transgenic glyphosate-resistant soybeans (grs) have been commercialized and grown extensively in the western hemisphere, including brazil. worldwide, several studies have shown that previous and potential effects of glyphosate on contamination of soil, water, and air are minimal, compared to those caused by the herbicides that they replace when grs are adopted. in the usa and argentina, the advent of glyphosate-resistant soybeans resulted in a significant shift to reduced- and no-tillage practic ... | 2007 | 17562462 |
| glyphosate-resistant weeds of south american cropping systems: an overview. | herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. in south america, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. the goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in south american agriculture. the first reports of glyphosate resistance include populations of highly diverse taxa (lolium multiflorum lam., ... | 2008 | 18161884 |
| agricultural impacts of glyphosate-resistant soybean cultivation in south america. | in the 2009/2010 growing season, brazil was the second largest world soybean producer, followed by argentina. glyphosate-resistant soybeans (grs) are being cultivated in most of the soybean area in south america. overall, the grs system is beneficial to the environment when compared to conventional soybean. grs resulted in a significant shift toward no-tillage practices in brazil and argentina, but weed resistance may reduce this trend. probably the highest agricultural risk in adopting grs in b ... | 2010 | 20839871 |
| chemical composition and biological activity of conyza bonariensis essential oil collected in mérida, venezuela. | the essential oil from aerial parts of conyza bonariensis (l) cronquist collected in mérida was obtained by hydrodistillation and analysed by gc/ms. the major components were trans-beta-farnesene (37.8%), trans-ocimene (20.7%) and beta-sesquiphellandrene (9.8%). cytotoxicity assay was also performed with the essential oil against hela (cervix carcinoma), a-459 (lung carcinoma) and mcf-7 (breast adenocarcinoma) human cell lines and against normal vero cells (african green monkey kidney) with ic50 ... | 2013 | 24079198 |
| gut modulator effects of conyza bonariensis explain its traditional use in constipation and diarrhea. | the current investigation was carried out to explore the pharmacological basis of the crude extract of conyza bonariensis (cb.cr) for its use in constipation and diarrhea. | 2013 | 23467958 |
| weedy hosts and prevalence of potential leafhopper vectors (hemiptera: cicadellidae) of a phytoplasma (16srix group) associated with huanglongbing symptoms in citrus groves. | huanglongbing (hlb) is a severe citrus (citrus spp.) disease associated with the bacteria genus candidatus liberibacter, detected in brazil in 2004. another bacterium was found in association with hlb symptoms and characterized as a phytoplasma belonging to the 16srix group. the objectives of this study were to identify potential leafhopper vectors of the hlb-associated phytoplasma and their host plants. leafhoppers were sampled every other week for 12 mo with sticky yellow cards placed at two h ... | 2012 | 22606800 |
| biology and management of two important conyza weeds: a global review. | weed management is one of the prime concerns for sustainable crop production. conyza bonariensis and conyza canadensis are two of the most problematic, noxious, invasive and widespread weeds in modern-day agriculture. the biology, ecology and interference of c. bonariensis and c. canadensis have been reviewed here to highlight pragmatic management options. both these species share a unique set of biological features, which enables them to invade and adapt a wide range of environmental conditions ... | 2016 | 27798798 |
| a new species of paracoccus ezzat and mcconnell (hemiptera: pseudococcidae) from southern brazil. | the worldwide mealybug genus paracoccus ezzat & mcconnell (hemiptera: coccomorpha: pseudococcidae) has eight described neotropical species, including two species known from brazil. in this article, we describe a third species from brazil: paracoccus galzerae pacheco da silva & kaydan sp. n., based on the morphology of adult females collected on the roots of conyza bonariensis (asteraceae) in vineyards in bento gonçalves city, rio grande do sul. a revised identification key including the new spec ... | 2016 | 27389187 |
| non-target-site glyphosate resistance in conyza bonariensis is based on modified subcellular distribution of the herbicide. | conyza spp. were the first broadleaf weeds reported to have evolved glyphosate resistance. several mechanisms have been proposed for glyphosate resistance. in an effort to elucidate the mechanism of this resistance in conyza bonariensis, possible target-site and non-target-site mechanisms were investigated in glyphosate-resistant (gr) c. bonariensis biotypes. | 2017 | 27098558 |
| physiological, morphological and biochemical studies of glyphosate tolerance in mexican cologania (cologania broussonetii (balb.) dc.). | in recent years, glyphosate-tolerant legumes have been used as cover crops for weed management in tropical areas of mexico. mexican cologania (cologania broussonetii (balb.) dc.) is an innate glyphosate-tolerant legume with a potential as a cover crop in temperate areas of the country. in this work, glyphosate tolerance was characterized in two mexican cologania (a treated (t) and an untreated (ut)) populations as being representatives of the species, compared in turn to a glyphosate-susceptible ... | 2016 | 26646239 |
| from sensitivity to resistance - factors affecting the response of conyza spp. to glyphosate. | conyza bonariensis and c. canadensis are troublesome weeds, particularly in fields with minimum tillage, on roadsides and in perennial crops. the distribution of these difficult-to-control species is further increased by the spread of glyphosate-resistant populations. a preliminary investigation has demonstrated the existence of various degrees of glyphosate tolerance/resistance in these populations, underscoring the need to examine the relationship between glyphosate efficacy and plant growth c ... | 2016 | 26573966 |
| conyza species: distribution and evolution of multiple target-site herbicide resistances. | distribution of conyza species is well correlated with human interference. multiple herbicide resistance is caused by the attempt to overcome resistance to one mode of action by overuse of another. conyza canadensis (cc) and conyza bonariensis (cb) are troublesome weeds around the world. extensive use of herbicides has led to the evolution of numerous conyza spp. herbicide-resistant populations. seeds of 91 cc and cb populations were collected across israel. they were mostly found (86 %) in road ... | 2015 | 25912190 |
| antioxidant and antibacterial activities of extracts from conyza bonariensis growing in yemen. | this study aims to examine the antioxidant and antibacterial activities and phenolic contents of conyza bonariensis growing in yemen. the whole plants of c. bonariensis were ultrasonically extracted by ethanol. the antioxidant activity of the extract was determined by 2,2-diphenyl-1-picrylhydrazyl (dpph) and β-carotene bleaching (bcb). the effectiveness of the extract on the growth inhibition of some indicators of foodborne illness bacteria were investigated by agar well diffusion assay. the tot ... | 2015 | 25553691 |
| partial replacement of barley grain and soybean meal by fleabane (conyza bonariensis) in diets of growing awassi lambs. | effects of partial substitution of barley grain and soybean meal with fleabane (fb) conyza bonariensis on growth performances and body compositions of 24 male local awassi lambs were studied. all lambs were male with an average bw of 20.3 kg (s.d. = 2.0 kg) at the beginning of the experiment. animals were randomly divided into four groups of six lambs each. lambs in each group received individually their cereal-soybean-based total mixed rations with levels of fb: 0, 50, 100 and 150 g/kg dry matt ... | 2012 | 23031470 |
| chemical composition of essential oils from leaves, stems, flower heads and roots of conyza bonariensis l. from tunisia. | the essential oils isolated at the flowering stage in spring, summer and autumn of the aerial and underground parts of conyza bonariensis l. growing in tunisia were analysed by gc and gc/ms; 143 constituents were identified, and among them 20 were major. the oils of c. bonariensis gathered in spring were rich in matricaria ester (1.2-67.3%), (z)-nerolidol (0.3-19.9%) and caryophyllene oxide (0.8-14.3%). in the summer samples, the oils of c. bonariensis were rich in matricaria ester (1.6-76.4%), ... | 2011 | 21240765 |
| two new glycosides from conyza bonariensis. | studies on conyza bonariensis (l.) cronq. led to the isolation of two new glycosides trivially named as erigeside e and f (1-2), along with two new source compounds; benzyl-beta-d-glucopyranoside (3) and 2-phenylethyl-beta-d-glucopyranoside (4). compounds 1, 3, and 4 are aromatic glycosides, while compound 2 is an alkyl glycoside. their structures were elucidated through mass spectrometric, and 1d- and 2d-nmr spectroscopic techniques, including 1h nmr, 13c nmr, hmqc, hsqc and hmbc. | 2010 | 20734949 |
| differential susceptibility to glyphosate among the conyza weed species in spain. | greenhouse and laboratory experiments were conducted to investigate differences in glyphosate susceptibility among three species of the genus conyza introduced as weeds in spain: tall fleabane (conyza sumatrensis), hairy fleabane (conyza bonariensis), and horseweed (conyza canadensis). plant material was obtained from seeds collected in weed populations growing in olive groves and citrus orchards in southern spain, with no previous history of glyphosate application. dose-response curves displaye ... | 2010 | 20225860 |
| the effect of several adjuvants on glufosinate effectiveness in conyza species. | the effect of several adjuvants on the effectiveness of glufosinate and the role of adherence and contact angle modifications due to the presence of these adjuvants in the spraying solution on the increase in efficacy observed on the broadleaved weeds conyza albida and conyza bonariensis has been determined under laboratory controlled conditions. the adjuvants used on the experiment were a mixture of methyl oleate and palmitate (mo/mp), a dodecylbenzene ammonium sulphonate (dbas), a paraffinic o ... | 2009 | 20222614 |
| constitutively elevated levels of putrescine and putrescine-generating enzymes correlated with oxidant stress resistance in conyza bonariensis and wheat. | oxidant stress resistance in conyza bonariensis and wheat (triticum aestivum) has been correlated with high levels of antioxidant enzyme activities. additionally, external oxidant stresses can increase a plant's levels of the enzymes of polyamine biosynthesis and polyamines, especially putrescine. we investigated the constitutive relationships between putrescine, putrescine-generating enzymes, and oxidant stress resistance in wheat and c. bonariensis. putrescine was constitutively elevated (2.5- ... | 1997 | 12223875 |
| glycosides and xanthine oxidase inhibitors from conyza bonariensis. | fractionation of the xanthine oxidase inhibitory methanol extract of conyza bonariensis afforded three glycosides, in addition to nine known compounds including amyrin, beta-sitostero1 daucosterol, syringic acid 3-hydroxy-5-methoxybenzoic acid, eugenol 4-o-glucopyranoside, and luteolin, apigenin and takakin 8-o-glucuronide. the structures of the glycosides were established by a combination of spectroscopic methods (ir, ms, 1h and 13c nmr, dept, cosy, hmqc and hmbc) as 4-hydroxypyridin-3-carboxyl ... | 2001 | 11576616 |
| transient, oxidant-induced antioxidant transcript and enzyme levels correlate with greater oxidant-resistance in paraquat-resistant conyza bonariensis. | the elucidation of mechanisms plants use to overcome oxidative stress is facilitated where there is intra-specific genetic variability. the differential induction of higher levels of mrnas, cytosol and chloroplast antioxidant enzyme activities, and proteins occurred after sub-lethal paraquat treatment of the oxidant-resistant biotype of conyza bonariensis (l.) cronq. by 6 h after sub-lethal paraquat treatment the activities of superoxide dismutase (ec 1.15.1.1), ascorbate peroxidase (ec 1.11.1.1 ... | 2000 | 10923703 |
| developmental variability of photooxidative stress tolerance in paraquat-resistant conyza. | paraquat-resistant hairy fleabane (conyza bonariensis l. cronq.) has been extensively studied, with some contention. a single, dominant gene pleiotropically controls levels of oxidant-detoxifying enzymes and tolerance to many photooxidants, to photoinhibition, and possibly to other stresses. the weed forms a rosette on humid short days and flowers in dry long days and, thus, needs plasticity to photooxidant stresses. in a series of four experiments over 20 months, the resistant and susceptible b ... | 1993 | 12232004 |
| increased tolerance to photoinhibitory light in paraquat-resistant conyza bonariensis measured by photoacoustic spectroscopy and co(2)-fixation. | tolerance to photoinhibition was compared between a paraquat-resistant and a sensitive biotype of conyza bonariensis (l.). cronq. photoinhibitory damage was measured as a decrease in oxygen evolution or energy storage using photoacoustic spectroscopy, or as a decrease of (14)co(2)-fixation. prior to exposure to high fluence rates, both biotypes had similar quantum yields of oxygen evolution and energy storage. after exposure to high intensity light, the resistant biotype continued to evolve oxyg ... | 1989 | 16667129 |
| kinetic analysis of resistance to paraquat in conyza: evidence that paraquat transiently inhibits leaf chloroplast reactions in resistant plants. | paraquat resistance has been claimed to be due to a sequestration of the herbicide before it reaches chloroplasts. this is based on the sensitivity of photosystem i in isolated thylakoids to paraquat, and autoradiographic analyses showing label from paraquat near veins 4 hours after treatment of a resistant biotype. conversely, the enzymes of the superoxide detoxification pathway were found to be at constitutively elevated levels in intact class a chloroplasts of the resistant biotype of conyza ... | 1987 | 16665821 |
| paraquat resistance in conyza. | a biotype of conyza bonariensis (l.) cronq. (identical to conyza linefolia in other publications) originating in egypt is resistant to the herbicide 1,1'-dimethyl-4,4'-bipyridinium ion (paraquat). penetration of the cuticle by [(14)c]paraquat was greater in the resistant biotype than the susceptible (wild) biotype; therefore, resistance was not due to differences in uptake. the resistant and susceptible biotypes were indistinguishable by measuring in vitro photosystem i partial reactions using p ... | 1985 | 16664176 |
| allergic contact dermatitis to saliva officinalis, inula viscosa and conyza bonariensis. | | 1978 | 743885 |