| determination and study on dissipation and residue determination of cyhalofop-butyl and its metabolite using hplc-ms/ms in a rice ecosystem. | cyhalofop-butyl is an aryloxyphenoxypropionate postemergence herbicide with good control of barnyard grass in rice paddies. in this study, method for the determination of cyhalofop-butyl and its metabolite was developed with high-performance liquid chromatography tandem mass spectrometry. dissipation and residue levels of cyhalofop-butyl and its metabolite in rice ecosystems were also investigated. recoveries and relative standard deviations of cyhalofop-butyl and cyhalofop acid in six matrices ... | 2014 | 25007772 |
| two novel phytotoxic substances from leucas aspera. | leucas aspera (lamiaceae), an aromatic herbaceous plant, is well known for many medicinal properties and a number of bioactive compounds against animal cells have been isolated. however, phytotoxic substances from l. aspera have not yet been documented in the literature. therefore, current research was conducted to explore the phytotoxic properties and substances in l. aspera. aqueous methanol extracts of l. aspera inhibited the germination and growth of garden cress (lepidum sativum) and barnya ... | 2014 | 24913044 |
| structure-activity relationship studies of the phytotoxic properties of the diterpenic moiety of breviones. | brevianes are a family of bioactive meroterpenoids originally described in fungi of the family penicillium. these compounds have attracted a great deal of interest not only because of their unusual skeleton, suggesting a mixed mevalonate and polyketide biogenetic pathway, and their unusual oxa-spiro ring fused to an α-pyrone, but also because of the bioactivities shown by many members of this family. | 2015 | 24839263 |
| using next-generation sequencing to detect mutations endowing resistance to pesticides: application to acetolactate-synthase (als)-based resistance in barnyard grass, a polyploid grass weed. | next-generation sequencing (ngs) technologies offer tremendous possibilities for accurate detection of mutations endowing pesticide resistance, yet their use for this purpose has not emerged in crop protection. this study aims at promoting ngs use for pesticide resistance diagnosis. it describes a simple procedure accessible to virtually any scientist and implementing freely accessible programs for the analysis of ngs data. | 2015 | 24777558 |
| pollen-mediated transfer of herbicide resistance in echinochloa crus-galli. | pollen-mediated gene flow (pmgf) can facilitate the dispersal and spread of herbicide resistance from one weed population to another within an agricultural landscape. the aim of this study was to quantify the extent of pmgf in echinochloa crus-galli (barnyardgrass), an important herbicide-resistant weed species in the united states and across the world. | 2014 | 24623467 |
| herbicide sensitivity of echinochloa crus-galli populations: a comparison between cropping systems. | echinochloa crus-galli populations exhibit high morphological variability and their response to herbicides varies from field to field. differential response to herbicides could reflect differences in selection pressure, caused by years of cropping system related herbicide usage. this study investigates the relation between herbicide sensitivity of echinochloa crus-galli populations and the cropping system to which they were subjected. the herbicide sensitivity of echinochloa crus-galli was evalu ... | 2014 | 26084085 |
| a novel hairpin-like antimicrobial peptide from barnyard grass (echinochloa crusgalli l.) seeds: structure-functional and molecular-genetics characterization. | a novel plant hairpin-like defense polypeptide named ecamp3 was isolated from latent barnyard grass (echinochloa crusgalli l.) seeds. the native peptide and its recombinant analogue were characterized. ecamp3 displays antifungal and antibacterial activity in vitro. the gene family encoding ecamps precursor protein was also characterized; the genes and pseudogenes of this family show 97-100% homology. every member of ecamps precursor family contains seven identical cysteine motifs: c1xxxc2(11-13) ... | 2014 | 24275143 |
| discriminating crop, weeds and soil surface with a terrestrial lidar sensor. | in this study, the evaluation of the accuracy and performance of a light detection and ranging (lidar) sensor for vegetation using distance and reflection measurements aiming to detect and discriminate maize plants and weeds from soil surface was done. the study continues a previous work carried out in a maize field in spain with a lidar sensor using exclusively one index, the height profile. the current system uses a combination of the two mentioned indexes. the experiment was carried out in a ... | 2013 | 24172283 |
| identification and mrna expression profile of glutamate receptor-like gene in quinclorac-resistant and susceptible echinochloa crus-galli. | animal ionotropic glutamate receptors (iglurs) function as ca(2+) ion channels during excitatory neurotransmission in nerve cells. here, a glutamate receptor-like gene (glr) was identified and characterized from a plant - echinochloa crus-galli. the glr gene was designated ecglr1 with genbank no: jx518597. it has a 2,793 bp open reading frame predicted to encode a 101.7 kda protein. sequence alignment showed that ecglr1 is a glr homologue. its expression in response to quinclorac treatment was a ... | 2013 | 24036427 |
| [research on discrimination of cabbage and weeds based on visible and near-infrared spectrum analysis]. | the automatic identification of weeds forms the basis for precision spraying of crops infest. the canopy spectral reflectance within the 350-2 500 nm band of two strains of cabbages and five kinds of weeds such as barnyard grass, setaria, crabgrass, goosegrass and pigweed was acquired by asd spectrometer. according to the spectral curve characteristics, the data in different bands were compressed with different levels to improve the operation efficiency. firstly, the spectrum was denoised in acc ... | 2013 | 23905319 |
| de novo assembly and characterization of the barnyardgrass (echinochloa crus-galli) transcriptome using next-generation pyrosequencing. | barnyardgrass (echinochloa crus-galli) is an important weed that is a menace to rice cultivation and production. rapid evolution of herbicide resistance in this weed makes it one of the most difficult to manage using herbicides. since genome-wide sequence data for barnyardgrass is limited, we sequenced the transcriptomes of susceptible and resistant barnyardgrass biotypes using the 454 gs-flx platform. | 2013 | 23874903 |
| root distribution and potential interactions between allelopathic rice, sprangletop (leptochloa spp.), and barnyardgrass (echinochloa crus-galli) based on ¹³c isotope discrimination analysis. | weed-suppressive rice cultivars hold promise for improved and more economical weed management in rice. interactions between roots of rice and weeds are thought to be modulated by the weed-suppressive activity of some rice cultivars, but these phenomena are difficult to measure and not well understood. thus, above-ground productivity, weed suppression, and root distribution of 11 rice cultivars and two weed species were evaluated in a drill-seeded, flood-irrigated system at stuttgart, arkansas, u ... | 2013 | 23397455 |
| allelopathy is involved in the formation of pure colonies of the fern gleichenia japonica. | the fern gleichenia japonica is one of the most widely distributed fern and occurs throughout east to south asia. the species often dominates plant communities by forming large monospecific colonies. however, the potential mechanism for this domination has not yet been described. the objective of this study was to test the hypothesis that allelochemicals are involved in the formation of g. japonica colonies. an aqueous methanol extract of g. japonica inhibited the growth of seedlings of garden c ... | 2013 | 23286996 |
| biology of rice bug leptocorisa oratorius (fabricius) (hemiptera: alydidae), population change and alternative host plants. | leptocorisa oratorius (fabricius) (hemiptera: alydidae) is a major rice pest which feeds on the sap of stems and rice seeds. some graminaceous weed species serve as an alternative host of l. oratorius causing outbreaks throughout the rice growing season. population changes of l. oratorius during both rice growing seasons - wet-season rice and dry-season rice - including the influence of alternative host, barnyard grass echinochloa crus-galli (graminaceae) on the development of l. oratorius was s ... | 2013 | 25145240 |
| physiological and molecular basis of acetolactate synthase-inhibiting herbicide resistance in barnyardgrass (echinochloa crus-galli). | barnyardgrass biotypes from arkansas (ar1 and ar2) and mississippi (ms1) have evolved cross-resistance to imazamox, imazethapyr, and penoxsulam. additionally, ar1 and ms1 have evolved cross-resistance to bispyribac-sodium. studies were conducted to determine if resistance to acetolactate synthase (als)-inhibiting herbicides in these biotypes is target-site or non-target-site based. sequencing and analysis of a 1701 base pair als coding sequence revealed ala₁₂₂ to val and ala₁₂₂ to thr substituti ... | 2013 | 23237199 |
| phytotoxic effect, uptake, and transformation of biochanin a in selected weed species. | certain isoflavones are plant growth inhibitors, and biochanin a is a major isoflavone in clover species used for weed management. the effect of biochanin a on the monocot weed species echinochloa crus-galli l. and lolium perenne l. and dicot species silene noctiflora l., geranium molle l., and amaranthus caudatus l. was evaluated in agar medium bioassays. s. noctiflora and g. molle root growth was progressively inhibited with increasing concentrations of biochanin a, whereas the monocot species ... | 2012 | 23030687 |
| adaptation to flooding during emergence and seedling growth in rice and weeds, and implications for crop establishment. | direct seeding of rice is being adopted in rainfed and irrigated lowland ecosystems because it reduces labour costs in addition to other benefits. however, early flooding due to uneven fields or rainfall slows down seed germination and hinders crop establishment. conversely, early flooding helps suppress weeds and reduces the costs of manual weeding and/or dependence on herbicides; however, numerous weed species are adapted to lowlands and present challenges for the use of flooding to control we ... | 2012 | 22957137 |
| barnyard grass stress up regulates the biosynthesis of phenolic compounds in allelopathic rice. | allelopathic rice cultivar pi312777 (pi) and non-allelopathic rice cultivar lemont (le) were mixed with barnyard grass (echinochloa crus-galli l., byg) at various ratios (rice:weed ratios of 4:1, 2:1, and 1:1) in hydroponic cultures. the expression of four genes, i.e. phenylalanine ammonia-lyase (pal), cinnamate-4-hydroxylase (c4h), ferulic acid 5-hydroxylase (f5h), and caffeic acid o-methyltransferases (comt), which are involved in the biosynthesis of the phenolic compounds in rice, were evalua ... | 2012 | 22939271 |
| [occurrence and ecological consequences of transgenic rice gene flow: a review]. | china is one of the origin centers of rice (oryza sativa), with a distribution of abundant wild rice germplasm resources. since the biosafety certificates were issued to bt transgenic rice containing cry1ac gene against lepidopteran pests, concerns are raised on the gene flow from transgenic rice to its wild relatives. this paper reviewed the occurrence of transgenic rice gene flow and its potential ecological consequences. most studies suggested that transgenic rice could successfully hybridize ... | 2012 | 22937665 |
| β-pinene inhibited germination and early growth involves membrane peroxidation. | β-pinene, an oxygenated monoterpene, is abundantly found in the environment and widely occurring in plants as a constituent of essential oils. we investigated the phytotoxicity of β-pinene against two grassy (phalaris minor, echinochloa crus-galli) and one broad-leaved (cassia occidentalis) weeds in terms of germination and root and shoot growth. β-pinene (0.02-0.80 mg/ml) inhibited the germination, root length, and shoot length of test weeds in a dose-response manner. the inhibitory effect of β ... | 2013 | 22936022 |
| identification and mechanism of echinochloa crus-galli resistance to fenoxaprop-p-ethyl with respect to physiological and anatomical differences. | identification and mechanism of echinochloa crus-galli (l.) resistance to fenoxaprop-p-ethyl via physiological and anatomical differences between susceptible and resistant were investigated. the physiological and anatomical differences that were take into account were growth reduction, chlorophyll content reduction, lamina thickness, and xylem vessel diameter in both susceptible and resistant biotypes of e. crus-galli. the results showed that the growth reduction fifty (gr₅₀) of resistant biotyp ... | 2012 | 22666165 |
| screening and identification of insertion mutants from bipolaris eleusines by mutagenesis based on restriction enzyme-mediated integration. | ophiobolin a is sesterterpenoid-type phytotoxin and may be an important candidate for development of new crop protection and pharmaceutical products. the restriction enzyme-mediated integration (remi) method was used to introduce the plasmid psh75 into the ophiobolin a-producing filamentous fungus bipolaris eleusines. a total of 323 stable transformants were obtained, all of which were capable of growing on potato-dextrose agar medium containing 200 μg ml(-1) hygromycin b. the transformation fre ... | 2012 | 22432435 |
| facile synthesis and herbicidal evaluation of 4h-3,1-benzoxazin-4-ones and 3h-quinazolin-4-ones with 2-phenoxymethyl substituents. | series of 4h-3,1-benzoxazin-4-ones and 3h-quinazolin-4-ones with phenoxy-methyl substituents were rationally designed and easily synthesized via one-pot n-acylation/ring closure reactions of anthranilic acids with 2-phenoxyacetyl chlorides to yield the 4h-3,1-benzoxazin-4-ones, and subsequently substituted with amino derivatives to obtain the 3h-quinazolin-4-ones. the herbicidal evaluation was performed on the model plants barnyard grass (a monocotyledon) and rape (a dicotyledon), and most of th ... | 2012 | 22418925 |
| the sesquiterpenes β-caryophyllene and caryophyllene oxide isolated from senecio salignus act as phytogrowth and photosynthesis inhibitors. | the n-hexane extract of s. salignus plants inhibited atp synthesis and two sesquiterpenes, the β-caryophyllene (1) and caryophyllene oxide (2) were isolated from this nonpolar fraction. compound 1 inhibited by 42% the root elongation of physalis ixocarpa seedlings at 50 µg/ml and by 53% at 150 µg/ml, whereas at 150 µg/ml this compound only inhibited root elongation of echinochloa crus-galli by 30%. on the other hand, compound 2 had no effect on either germination or root and stem growth of e. cr ... | 2012 | 22310166 |
| genetic evidence for natural product-mediated plant-plant allelopathy in rice (oryza sativa). | • there is controversy as to whether specific natural products play a role in directly mediating antagonistic plant-plant interactions - that is, allelopathy. if proved to exist, such phenomena would hold considerable promise for agronomic improvement of staple food crops such as rice (oryza sativa). • however, while substantiated by the presence of phytotoxic compounds at potentially relevant concentrations, demonstrating a direct role for specific natural products in allelopathy has been diffi ... | 2012 | 22150231 |
| phytotoxicity and uptake of nitroglycerin in a natural sandy loam soil. | nitroglycerin (ng) is widely used for the production of explosives and solid propellants, and is a soil contaminant of concern at some military training ranges. ng phytotoxicity data reported in the literature cannot be applied directly to development of ecotoxicological benchmarks for plant exposures in soil because they were determined in studies using hydroponic media, cell cultures, and transgenic plants. toxicities of ng in the present studies were evaluated for alfalfa (medicago sativa), b ... | 2011 | 21975007 |
| disulfide-stabilized helical hairpin structure and activity of a novel antifungal peptide ecamp1 from seeds of barnyard grass (echinochloa crus-galli). | this study presents purification, activity characterization, and (1)h nmr study of the novel antifungal peptide ecamp1 from kernels of barnyard grass echinochloa crus-galli. the peptide adopts a disulfide-stabilized α-helical hairpin structure in aqueous solution and thus represents a novel fold among naturally occurring antimicrobial peptides. micromolar concentrations of ecamp1 were shown to inhibit growth of several fungal phytopathogens. confocal microscopy revealed intensive ecamp1 binding ... | 2011 | 21561864 |
| breeding of commercially acceptable allelopathic rice cultivars in china. | one promising area of paddy weed control is the potential for exploiting the weed-suppressing ability of rice. this study was conducted to develop commercially acceptable allelopathic rice cultivars using crosses between allelopathic rice variety pi312777 and commercial chinese cultivars (n2s, n9s, huahui354, peiai64s and tehuazhan35), and to assess their weed suppression and grain yield in paddy fields in relation to their parents. | 2011 | 21520392 |
| barnyard grass-induced rice allelopathy and momilactone b. | here, we investigated chemical-mediated interaction between crop and weeds. allelopathic activity of rice seedlings exhibited 5.3-6.3-fold increases when rice and barnyard grass seedlings were grown together, where there may be the competitive interference between rice and barnyard grass for nutrients. barnyard grass is one of the most noxious weeds in rice cultivation. the momilactone b concentration in rice seedlings incubated with barnyard grass seedlings was 6.9-fold greater than that in ric ... | 2011 | 21392842 |
| discrimination of corn from monocotyledonous weeds with ultraviolet (uv) induced fluorescence. | in production agriculture, savings in herbicides can be achieved if weeds can be discriminated from crop, allowing the targeting of weed control to weed-infested areas only. previous studies demonstrated the potential of ultraviolet (uv) induced fluorescence to discriminate corn from weeds and recently, robust models have been obtained for the discrimination between monocots (including corn) and dicots. here, we developed a new approach to achieve robust discrimination of monocot weeds from corn ... | 2011 | 21211148 |
| sensitivity of echinochloa muricata and echinochloa crus-galli to hppd- and als-inhibiting herbicides in corn. | until recently echinochloa muricata var. microstachya wiegand (rough barnyardgrass), an alien species native to north america, was completely overlooked in belgium due to its close morphological resemblance to echinochloa crus-galli (l.) p. beauv. (barnyardgrass). e. muricata var. microstachya has gradually spread and is now locally naturalized and abundant in and along maize fields. one of the possible reasons for its expansion in maize fields, besides e.g. the lack of crop rotation, might be a ... | 2011 | 22696959 |
| toxicity of 2,4-dinitrotoluene to terrestrial plants in natural soils. | the presence of energetic materials (used as explosives and propellants) at contaminated sites is a growing international issue, particularly with respect to military base closures and demilitarization policies. improved understanding of the ecotoxicological effects of these materials is needed in order to accurately assess the potential exposure risks and impacts on the environment and its ecosystems. we studied the toxicity of the nitroaromatic energetic material 2,4-dinitrotoluene (2,4-dnt) o ... | 2010 | 20471667 |
| evaluation of allelopathic, decomposition and cytogenetic activities of jasminum officinale l. f. var. grandiflorum (l.) kob. on bioassay plants. | methanolic extracts prepared from dried leaves of jasminum officinale f. var. grandiflorum (l.) kob. (spanish jasmine) inhibited seed germination and stunted both root and shoot length of the weeds echinochloa crus-galli (l.) beauv. and phaseolus lathyroides l. the main active compound was isolated and determined by spectral data as a secoiridoid glucoside named oleuropein. in addition, a decrease in allelopathic efficacy appeared as the decomposition periods increased. the mitotic index in trea ... | 2010 | 20199861 |
| contribution of momilactone a and b to rice allelopathy. | eight cultivars of rice (oryza sativa l.) inhibited shoot and root growth of echinochloa crus-galli when co-cultured with rice seedlings in a bioassay medium. momilactone a and b were found in the bioassay medium of all rice cultivars, and concentrations of momilactone a and b in the medium were 0.21-1.5 and 0.66-3.8 micromol/l, respectively, indicating that all rice cultivars may secrete momilactone a and b into the medium. exogenously applied momilactone a and b inhibited the growth of shoots ... | 2010 | 20170980 |
| enhanced heavy metal phytoextraction by echinochloa crus-galli using root exudates. | heavy metal uptake and growth by echinochloa crus-galli were investigated to determine if the use of root exudates enhanced phytoextraction. e. crus-galli were planted in soils contaminated with 600 mg kg(-1) pb, 40 mg kg(-1) cd and 100 mg kg(-1) cu. e. crus-galli were then cultivated with and without root exudates from belamcanda chinensis for 4 weeks. the growth of e. crus-galli in metal-contaminated soils that contained root exudates showed increased roots and shoots when compared to e. crus- ... | 2010 | 20129081 |
| comparison of the ability of organic acids and edta to enhance the phytoextraction of metals from a multi-metal contaminated soil. | chelates have been shown to enhance the phytoextraction of metal from contaminated soil. in this study, we evaluated the ability of chelates to enhance the phytoextraction of metals by barnyard grass (echinochloa crus-galli) from soils contaminated with multiple metals. the results revealed that edta increased the ability of barnyard grass to take up cd, cu and pb, but that it resulted in increased soil leaching. conversely, citric acid induced the removal of cd, cu and pb from soil without incr ... | 2010 | 19806283 |
| simulating the evolution of glyphosate resistance in grains farming in northern australia. | the evolution of resistance to herbicides is a substantial problem in contemporary agriculture. solutions to this problem generally consist of the use of practices to control the resistant population once it evolves, and/or to institute preventative measures before populations become resistant. herbicide resistance evolves in populations over years or decades, so predicting the effectiveness of preventative strategies in particular relies on computational modelling approaches. while models of he ... | 2009 | 19567415 |
| aromatic-ring-functionalised benzoxazinones in the system oryza sativa-echinochloa crus-galli as biorational herbicide models. | barnyardgrass, echinochloa crus-galli (l.) beauv., is one of the most problematic weeds occurring in rice crops. although efficient chemical control is provided by herbicides available on the market, resistant biotypes provoked by pressure selection have appeared in recent times. this emphasises the need for alternative treatments in which herbicidal compounds from a natural origin could be included. | 2009 | 19551813 |
| [research on distinguishing weed from crop using spectrum analysis technology]. | automatic detection of weeds is necessary for site--specific application of herbicides or precise physical weed control. leaf reflectance is mainly determined by photosynthetic pigments, leaf structural properties and water content, so spectral reflectance characteristics can be used for weed discrimination. the spectral reflectance of cotton, rice and weeds was determined in the range from 350 to 2 500 nm using the analytical spectral device full range fieldspec pro (asd) in laboratory. the dis ... | 2009 | 19445228 |
| [changes of microbial biomass carbon and enzyme activities in rice-barnyard grass coexisted soils]. | taking barnyard grass (echinochloa crus-galli), allelopathic rice (oryza sativa) pi312777, and non-allelopathic rice liaojing-9 as test materials, this paper studied the changes of microbial biomass c and of dehydrogenase, urease and invertase activities in soils under 1 : 1 rice-barnyard grass coexistence. the results showed that with the coexistence of barnyard grass, the microbial biomass c in rhizosphere soil of pi312777 was decreased by 50.52% (p < 0.01), while that in inter-row soil was in ... | 2008 | 19123361 |
| modified benzoxazinones in the system oryza sativa-echinochloa crus-galli: an approach to the development of biorational herbicide models. | the utility of benzoxazinones and some of their synthetic derivatives in the search for new leads for herbicide model development has been explored. the work described focuses on obtaining derivatives that present selectivity in the system oryza sativa- echinochloa crus-galli. to achieve this goal the influence of lipophilicity in this system has been studied by preparing 14 ester derivatives at the n-4 position of d-diboa along with other compounds with different functionalization and chain len ... | 2008 | 18922010 |
| wild plants, andropogon virginicus l. and miscanthus sinensis anders, are tolerant to multiple stresses including aluminum, heavy metals and oxidative stresses. | to isolate high-tolerant plants against aluminum (al), heavy metals and/or oxidative stresses as a final goal, screening of al tolerant plants from a collection of 49 wild plants was first of all performed in this study. andropogon virginicus l. and miscanthus sinensis anders showed high al tolerant phenotypes (more than 35% values in both relative root growth and germination frequency even under 900 microm al concentration) in our screening. al tolerance mechanisms in these two plants were char ... | 2008 | 18204843 |
| [regulation effects of arbuscular mycorrhizal fungi on the interactions between barnyard grass and upland rice under enhanced nitrogen supply]. | a pot experiment was conducted to study the regulation effects of arbuscular mycorrhizal fungi (amf) on the interactions between echinochloa crus-galli var. mitis l. and oryza sativa l. under enhanced n supply (4.0 g n x m(-2) x a(-1)). the results showed that under monoculture condition, the amf colonization on e. crus-galli increased but that on o. sativa decreased. in the treatments with and without amf inoculation, upland rice biomass and its p and n uptake increased by 42.35% and 13.48%, 4. ... | 2007 | 18163320 |
| mechanism of selective phytotoxicity of l-3,4-dihydroxyphenylalanine (l-dopa) in barnyardgrass and lettuce. | l-3,4-dihydroxyphenylalanine (l-dopa) is one of the few allelochemicals in which the phytotoxic action mechanism has been studied. excess exogenous l-dopa suppresses root elongation in some plant species, and the inhibitory action is species-selective. the main factor of phytotoxicity of l-dopa is considered to be oxidative damage by reactive oxygen species (ros) and/or free radical species (frs). this study was performed to elucidate the mechanism of species-selective phytotoxicity. the involve ... | 2007 | 17899281 |
| rice allelopathy induced by methyl jasmonate and methyl salicylate. | methyl jasmonate (meja) and methyl salicylate (mesa) are important signaling molecules that induce plant defense against insect herbivores and microbial pathogens. we tested the hypothesis that allelopathy is an inducible defense mechanism, and that the ja and sa signaling pathways may activate allelochemicals release. exogenous application of meja and mesa to rice (oryza sativa l.) enhanced rice allelopathic potential and led to accumulation of phenolics, an increase in enzymatic activities, an ... | 2007 | 17415624 |
| weed control in rice with metham-sodium. | metam-sodium is a soil fumigant with herbicidal properties. a field experiment was conducted in 2000 at copiano (pavia, italy) to determine the efficacy of three rates of metam-sodium (300, 450 and 600 l/ha) at three different planting times (5, 12 and 18 days after chemical treatments) for the control of weeds in rice cultivation. the study mainly focused on the control of red rice (oryza sativa var. selvatica), a weed which is worldwide distributed in rice fields and difficult to eradicate tes ... | 2006 | 17390826 |
| synthesis and herbicidal activity of novel pyrazolo[3,4-d]pyrimidin-4-one derivatives containing aryloxyphenoxypropionate moieties. | the 6-(4-alkoxycarbonylalkoxy)phenoxy-3-alkylthio(alkylsulfonyl)-1-phenyl-5-(substituted phenyl)pyrazolo[3,4-d]pyrimidin-4-ones 6 and 7 have been synthesized via the tandem aza-wittig and annulation reactions of the corresponding iminophosphoranes 4, aromatic isocyanates, and substituted phenols 2 in 52-98% yields. their structures were clearly verified by spectroscopic data (ir, (1)h nmr, (13)c nmr, ms, and elemental analysis or x-ray diffraction crystallography). and the results of preliminary ... | 2007 | 17337186 |
| design, synthesis, and quantitative structure-activity relationship study of herbicidal analogues of pyrazolo[5,1-d][1,2,3,5]tetrazin-4(3h)ones. | a series of pyrazolo[5,1-d][1,2,3,5]tetrazin-4(3h)one derivatives were designed, synthesized, and evaluated for their herbicidal activities where some of these compounds provided >80% control of brassica campestris at 10 microg/ml. quantitative structure-activity relationship studies were performed on these compounds using physicochemical parameters (electronic, verloop, or hydrophobic) as independent parameters and herbicidal activity as a dependent parameter, where herbicidal activity correlat ... | 2007 | 17300154 |
| [allelopathic potential and physiological mechanism of oryza sativa l. under phosphorus deficiency stress]. | in this paper, allelopathic rice pi312777 (pi) and non-allelopahtic rice lemont (le) were grown in the nutrient solution with two levels of phosphorus (p) supply, and their allelopathic effects on echinochloa crus-galli l. were studied. the results showed that under phosphorous deficiency stress, the inhibitory effect of pi on e. crus-galli root growth had an obvious increase. after growing in the nutrient solution with low p supply (0.5 mg x l(-1)) for 5, 10 and 15 days, the inhibitory rate of ... | 2006 | 17269328 |
| a quantitative structure-activity relationship study of herbicidal analogues of alpha-hydroxy-substituted 3-benzylidenepyrrolidene-2,4-diones. | a series of pyrrolidine-2,4-dione and piperidine-2,4-dione derivatives were prepared and evaluated for their herbicidal activities where some of these compounds exhibited good bioactivity against echinochloa crus-galli in comparison with sulcotrione. quantitative structure-activity relationship studies were performed on these compounds using physicochemical parameters (hydrophobic, electronic, and taft) as independent parameters and herbicidal activity as a dependent parameter, where herbicidal ... | 2006 | 16968083 |
| identification of phytotoxic substances from early growth of barnyard grass (echinochloa crusgalli) root exudates. | barnyard grass is a problematic weed worldwide. it competes with crops and causes reduction in crop yields. in this study, barnyard grass suppressed rice emergence, and the degree of rice inhibition was proportional to the density of barnyard grass. root exudates of barnyard grass reduced germination and growth of lettuce, rice, and monochoria. fifteen compounds potentially involved in the phytotoxic activities of barnyard grass were isolated and identified, including phenolics, long-chain fatty ... | 2006 | 16718576 |
| soil dissipation and biological activity of metolachlor and s-metolachlor in five soils. | the resolved isomer of metolachlor, s-metolachlor, was registered in 1997. new formulations based primarily on the s-metolachlor isomer are more active on a gram for gram metolachlor basis than formulations based on a racemic mixture of metolachlor containing a 50:50 ratio of the r and s isomers. the labelled use rates of s-metolachlor-based products were reduced by 35% to give equivalent weed control to metolachlor. however, several companies have recently registered new metolachlor formulation ... | 2006 | 16671061 |
| bioactive steroids from oryza sativa l. | rice is one of the most interesting crops in the world from both the social and the economic point of views. the monoculture practices along with the heavy use of herbicides are characteristic of modern agriculture and are inducing the appearance of tolerant and/or herbicide resistant weed biotypes. this is the case the world's main weed of rice barnyardgrass (echinochloa crus-galli). alternative strategies for weed suppression consist of the use of chemicals from rice due to necessity of obtain ... | 2006 | 16620896 |
| chemical composition and inhibitory activity of essential oil from decaying leaves of eucalyptus citriodora. | a study was undertaken to explore the content and composition of volatile oil from decaying leaves of lemon-scented eucalypt (eucalyptus citriodora hook.) not analyzed earlier. gc and gc-ms analysis of the oil (yield 0.6%) revealed the monoterpenoid nature with citronellal (52.2%), citronellol (12.3%) and isoisopulegol (11.9%) as the major constituents. overall, 17 components were identified that accounted for over 94% of the decaying leaf oil. surprisingly, the decaying leaf oil contained nearl ... | 2012 | 16610217 |
| evaluation of allelopathic potential and quantification of momilactone a,b from rice hull extracts and assessment of inhibitory bioactivity on paddy field weeds. | rice (oryza sativa l.) hull extracts were used in a bioassay to evaluate the allelopathic potential of rice on the germination and growth of barnyard grass (echinochloa crus-galli p. beauv. var. oryzicola ohwi), to quantify momilactone a and b levels in rice hull germplasm and to assess the inhibitory bioactivity of momilactone a and b as a potential natural source of herbicide for weed control in paddy fields. four varieties of weeds including e. crus-galli p. beauv. var. oryzicola ohwi, monoch ... | 2006 | 16569039 |
| 5-(2,6-difluorobenzyl)oxymethyl-5-methyl-3-(3-methylthiophen-2-yl)- 1,2-isoxazoline as a useful rice herbicide. | 5-(2,6-difluorobenzyl)oxymethyl-5-methyl-3-(3-methylthiophen-2-yl)-1,2-isoxazoline derivative was synthesized, and its herbicidal activity was assessed under glasshouse and flooded paddy conditions. 5-(2,6-difluorobenzyl)oxymethyl-5-methyl-3-(3-methylthiophen-2-yl)-1,2-isoxazoline demonstrated good rice selectivity and potent herbicidal activity against annual weeds at 125 g of a.i. ha(-1) under greenhouse conditions. soil application of this compound showed complete control of barnyard-grass to ... | 2005 | 16248565 |
| [prevention efficiency of exserohilum monoceras with chemical herbicides against echinochloa crus-galli in paddy field]. | this paper studied the impact of several herbicides on the conidium germination of exserohilum monoceras strain x27 in petri dish, and the synergistic effects of the pathogen and chemical herbicide quinclorac or propanil against echinochloa crus-galli in greenhouse. the prevention efficiency of the tank-mixture of pathogen and quinclorac was also evaluated in paddy field. the results showed that test herbicides except quinclorac and bensulfulfuronmethyl could inhibit conidium germination and hyp ... | 2005 | 16180763 |
| allelopathic potential of robinia pseudo-acacia l. | robinia pseudo-acacia l. (black locust) is a nonindigenous species currently invading the central part of japanese grasslands. several allelochemicals were identified and characterized from the leaf tissue. the growth of both radicle and hypocotyl in the tested species (barnyard grass, white clover, lettuce, and chinese cabbage) was reduced when grown in soil mixed with the leaves of r. pseudo-acacia at various concentrations. aqueous leaf extracts, when bioassayed, exhibited a significant suppr ... | 2005 | 16132219 |
| [inhibitory effects of allelopathic rice materials on echinochloa crus-galli and related field weeds]. | by using the modified relay seeding technique, more than 10 allelopathic rice materials were obtained from 500 rice germplasm, and their allelopathic inhibitory effects on weeds were evaluated under field condition. the results showed that under direct-seeded condition, the allelopathic rice materials gumei 2, xiayitiao, jizaoxian, ganzaoxian and shangnuo 1 had more obvious inhibitory effects on echinochloa crus-galli than non-allelopathic rice materials xiushui 63 and chunjiang 11, while the al ... | 2005 | 16011176 |
| structure-activity relationship studies of benzoxazinones and related compounds. phytotoxicity on echinochloa crus-galli (l.) p. beauv. | echinochloa crus-galli (e. crus-galli; barnyardgrass) is a weed widely distributed. it constitutes a serious weed problem in 42 countries and has been found in at least 27 more. it is the world's main weed of rice affecting up to 36 crops worldwide. several biotypes of this plant, with resistance to herbicides with different modes of action have evolved. in our ongoing studies regarding the potential application of benzoxazinones and their soil degradation products for weed control, a complete s ... | 2005 | 15913298 |
| determination of antagonism between cyhalofop-butyl and other rice (oryza sativa) herbicides in barnyardgrass (echinochloa crus-galli). | herbicide antagonism is defined as the reduction of control of certain weeds as the result of applying mixtures of two or more herbicides. cyhalofop-butyl, a graminicide used for postemergence grass weed control in rice, is antagonized by some rice herbicides when applied simultaneously. the result of this type of antagonism usually results in decreased control of grass weeds. research has shown that herbicide antagonism between graminicides and other herbicides may be caused by different mechan ... | 2005 | 15884840 |
| involvement of reactive oxygen species generated from melanin synthesis pathway in phytotoxicty of l-dopa. | l-dopa is an active allelochemical that inhibits plant growth. to determine whether the phytotoxicity is due to the reactive oxygen species generated during its oxidation to melanin, oxidative damage, melanin accumulation, and the effect of antioxidants on its phytotoxicity were examined in l-dopa-tolerant (barnyard grass) and -susceptible (lettuce) plants, and in suspension-cultured carrot cells. l-dopa suppressed root elongation in lettuce compared to barnyard grass. levels of melanin and thio ... | 2005 | 15856781 |
| synthesis, crystal structure and herbicidal activity of mimics of intermediates of the kari reaction. | two mimics of the intermediate in the reaction catalyzed by ketol-acid reductoisomerase (kari) were synthesized. their structures were established on the basis of elemental analyses, ir, 1h nmr and gc/mass detector. the crystal structure of compound 2 was found to be a substituted dioxane, formed by the condensation of two molecules. the two compounds showed some herbicidal activity on the basis of tests using rape root and barnyard grass growth inhibition. however, the herbicidal effect was wea ... | 2005 | 15751008 |
| [interference of allelopathic rice cultivars on barnyardgrass under different water irrigation and rice plant density]. | pot culture experiments were conducted to examine the effects of water irrigation and rice plant density on the interference of allelopathic rice on barnyardgrass (echinochloa crus-galli). the results showed that under water irrigations, allelopathic rice cultivars xiayitiao, gumei 2 and zhong 156 significantly reduced the plant height of barnyardgrass than non-allelopathic rice cultivars xiushui 63 and chunjiang 11. barnyardgrass plants grew shorter as rice plant density increased. allelopathic ... | 2004 | 15669488 |
| ek-2612, a new cyclohexane-1,3-dione possessing selectivity between rice (oryza sativa) and barnyardgrass (echinochloa crus-galli). | a newly synthesized experimental compound, ek-2612 is one of the class of cyclohexane-1,3-diones which are commonly known to be grasskillers. a greenhouse study was conducted to evaluate the herbicidal performances of ek-2612 on several grass species in comparison with tralkoxydim, a commercialized cyclohexanedione derivative. like tralkoxydim, the compound ek-2612 showed excellent control efficacy on most grass weeds tested through foliar application rates between 250 and 63 g ai ha(-1). unlike ... | 2004 | 15382506 |
| two compounds from allelopathic rice accession and their inhibitory activity on weeds and fungal pathogens. | a flavone (5,7,4'-trihydroxy-3',5'-dimethoxyflavone), a cyclohexenone (3-isopropyl-5-acetoxycyclohexene-2-one-1) and a liquid mixture of low polarity, containing long-chain and cyclic hydrocarbons, were isolated from leaves of allelopathic rice accession pi 312777 using column chromatography. their structures and constituents were identified by means of hr-ms, nmr and gc/ms analyses, respectively. bioassays showed that both the flavone and cyclohexenone significantly inhibited the growth of weed ... | 2004 | 15110693 |
| construction of a comparative rflp map of echinochloa crus-galli toward qtl analysis of flooding tolerance. | to analyze quantitative trait loci (qtls) affecting flooding tolerance and other physiological and morphological traits in echinochloa crus-galli, a restriction fragment length polymorphism (rflp) map was constructed using 55 plants of the f(2) population ( e. crus-galli var. praticola x e. crus-galli var. formosensis). one hundred forty-one loci formed 41 linkage groups. the total map size was 1,468 cm and the average size of linkage groups was 35.8 cm. the average distance between markers was ... | 2004 | 15067384 |
| [genes mapping on rice allelopathy against barnyardgrass]. | by using the relay seeding technique with slight modification, a population of 134 recombinant inbred lines (rils) derived from a cross between indica rice (oryza sativa l.) cultivar zhong 156 x gumei 2 and contained 168 dna markers covering all 12 chromosomes with 1447.9 cm spans was employed to evaluate the rice allelopathic effect on barnyardgrass [echinochloa crus-galli (i.) beauv.]. the phenotyping values of the biomass of barnyardgrass infested with rice materials were employed to map the ... | 2003 | 15031929 |
| genetic and biochemical analysis of anaerobically-induced enzymes during seed germination of echinochloa crus-galli varieties tolerant and intolerant of anoxia. | to compare the regulation of anaerobic metabolism during germination in anoxia-tolerant and intolerant plants, enzymes associated with anaerobic metabolism such as sucrose synthase, aldolase, enolase, pyruvate decarboxylase (pdc), alcohol dehydrogenase (adh), and aldehyde dehydrogenase (aldh) were assayed in two varieties of echinochloa crus-galli, formosensis (tolerant) and praticola (intolerant). the initial and intervening enzymes of the pathway (sucrose synthase and aldolase) and enzymes in ... | 2003 | 12709489 |
| designing herbicide formulation characteristics to maximize efficacy and minimize rice injury in paddy environments. | mathematical descriptors, coupled with experimental observations, are used to quantify differential uptake of an experimental herbicide in japonica and indica rice (oryza sativa, non-target) and barnyardgrass (echinochloa crus-galli, target). partitioning, degradation, plant uptake and metabolism are described using mass-balance conservation equations in the form of kinetic approximations. estimated environmental concentrations, governed by the pesticide formulation, are described using superimp ... | 2001 | 11407023 |
| allelopathic substance exuded from a serious weed, germinating barnyard grass (echinochloa crus-galli l.), roots. | the allelopathy of a serious weed, barnyard grass (echinochloa crus-galli l.), was investigated. root exudates of young barnyard grass showed allelopathic effects and plant-selective activity and inhibited root elongation of all plants tested. with respect to shoot growth, the exudates did not show inhibition of barnyard grass only. the allelopathic substance was isolated and identified as p-hydroxymandelic acid by nmr. p-hydroxymandelic acid strongly inhibited shoot growth and root elongation o ... | 1999 | 10552134 |
| localisation of sucrose-phosphate synthase and starch in leaves of c4 plants. | the activity and intercellular distribution of sucrose-phosphate synthase (sps; ec 2.4.1.14) were determined in fully expanded leaves from a range of c4 plants. in zea mays l. and atriplex spongiosa f. muell., sps was located almost exclusively in the mesophyll cells. in other species, sps was found in both cell types, with the activity in the bundle sheath cells ranging from 5% of the total leaf activity in echinochloa crus-galli (l.) beauv. to 35% in sorghum bicolor moench. at the end of the l ... | 1997 | 9177054 |
| geographic variation in seed dormancy among populations of echinochloa crus-galli. | in 1991-1993, we investigated the incidence of seed dormancy in 25 local populations of barnyard grass, echinochloa crus-galli (l.) p.beauv., in the western czech republic. the percentage of germination after 4 months afterripening of dry seeds at 25°c varied between 0.0 and 83.6%. although there were significant annual differences in the percentage of germination at some localities, typical proportions of dormant seeds persisted over 3 years at field sites where the seed bank was not disturbed. ... | 1996 | 28307856 |
| inhibition of barnyardgrass 4-hydroxyphenylpyruvate dioxygenase by sulcotrione. | 4-hydroxyphenylpyruvate dioxygenase (ec 1.13.11.27) was partially purified from barnyardgrass (echinochloa crus-galli l.) leaves and assayed by high-performance liquid chromatography analysis of product formation or by the capture of released 14co2. the bleaching herbicide sulcotrione [2-(2-chloro-4-methanesulfonylbenzoyl)-1,3-cyclohexanedione] was shown to be a potent, linear competitive inhibitor of 4-hydroxyphenylpyruvate dioxygenase. kinetic analyses determined that the km for the substrate, ... | 1994 | 12232420 |
| maternally-induced modification of progeny phenotypes in the c4 weed echinochloa crus-galli: an analysis of seed constituents and performance. | to clarify the physiological basis of maternal inheritance we examined the effect of the thermal environment of mother plants of echinochloa crus-galli on subsequent seed mass, content and quality. the same plants were grown in a warm and a cold environment until seeds were produced and, since e. crus-galli is a highly inbred species, the observed variation in seed production was a purely plastic response to the environment. when mother plants were grown at high temperature, average seed mass, v ... | 1993 | 28313439 |
| constitutive and inducible aerobic and anaerobic stress proteins in the echinochloa complex and rice. | anaerobic stress resulted in a change in the protein accumulation patterns in shoots of several echinochloa (barnyard grass) species and oryza sativa (l.) (rice) as resolved by two-dimensional gel electrophoresis. of the six echinochloa species investigated, e. phyllopogon (stev.) koss, e. muricata (beauv.) fern, e. oryzoides (ard.) fritsch clayton, and e. crus-galli (l.) beauv. are tolerant of anaerobiosis and germinate in the absence of oxygen, as does rice. in contrast, e. crus-pavonis (h.b.k ... | 1993 | 12231678 |
| mitochondrial enzymes in aerobically and anaerobically germinated seedlings of echinochloa and rice. | activities of tricarboxylic acid (tca) cycle enzymes in seedlings of barnyard grass (echinochloa phyllopogon (stapf.) koss) and rice (oryza sativa l.) germinated under aerobic and anaerobic conditions were investigated. in e. phyllopogon, development of tca-cycle enzyme activities during 10 d of anoxia generally paralleled those in air, although at lower rates. after 5 d, e. phyllopogon seedlings germinating under n2 exhibited 50-80% of the activity of seedlings grown in air, except for 2-oxoglu ... | 1991 | 24194241 |
| changes in the composition and synthesis of proteins in cellular membranes of echinochloa crus-galli (l.) beauv. seeds during the transition from dormancy to germination. | the effect of alcohols which stimulate or have no effect on germination on the composition and synthetic pattern of proteins in the cellular membranes of echinochloa crus-galli (l.) beauv. seeds was studied. imbibition of dry seeds was accompanied by an increase in the synthesis of proteins and by synthesis of new proteins in their intracellular membranes. the transition of the seeds from a dormant to a nondormant state was associated with synthesis of specific proteins and a decrease in content ... | 1990 | 16667293 |
| effects of temperature and co2 enrichment on kinetic properties of nadp(+)-malate dehydrogenase in two ecotypes of barnyard grass (echinochloa crus-galli (l.) beauv.) from contrasting climates. | the apparent energy of activation (e a), michaelis-menten constant (k mfor oxaloacetate), v max/k mratios and specific activities of nadp(+)-malate dehydrogenase (nadp(+)-mdh; ec 1.1.1.82) were analyzed in plants of barnyard grass from québec (que) and mississippi (miss) acclimated to two thermoperiods 28/22°c, 21/15°c, and grown under two co2 concentrations, 350 μl l(-1) and 675 μl l(-1). e avalues of nadp(+)-mdh extracted from que plants were significantly lower than those of miss plants. k mv ... | 1989 | 28312170 |
| differences in the anaerobic lactate-succinate production and in the changes of cell sap ph for plants with high and low resistance to anoxia. | anaerobically treated seedlings of oryza sativa l. var arborio accumulated in their shoots more succinate than lactate and cell sap became alkaline. conversely, in triticum aestivum l. var mek 86 lactate accumulation was far higher than that of succinate and cell sap was acidified. anoxia clearly induced proton consumption in both species as an important means to prevent or counteract acidosis. other species studied were: echinochloa crus-galli l. beauv., zea mays l. var de kalb xl75, secale cer ... | 1989 | 16666751 |
| activities of isolated mitochondria and mitochondrial enzymes from aerobically and anaerobically germinated barnyard grass (echinochloa) seedlings. | activity of mitochondria isolated from whole seedlings of echinochloa crus-galli (l.) beauv. var oryzicola germinated under aerobic and anaerobic conditions for 5 to 7 days was investigated. mitochondria from both treatments exhibited good respiratory control and adp/o ratios. although o(2) uptake was low in anaerobic mitochondria, activity rapidly increased when the seedlings were transferred to air. mitochondria from both aerobically and anaerobically grown seedlings of e. crus-galli var oryzi ... | 1987 | 16665723 |
| effect of low temperature on the photosynthetic metabolism of the c4 grass echinochloa crus-galli. | co2 curves of photosynthesis and activities of the four c4 enzymes and ribulose bisphosphate carboxylase (rubpc) were compared in two populations of the c4 grass echinochloa crus-galli from contrasting thermal environments (québec and mississippi). analyses were conducted both before and after 14 h of chilling at 7°c under high light conditions. this comparison provides the opportunity to assess which steps of the c4 pathway are more susceptible to become limiting at low temperatures. both popul ... | 1986 | 28311607 |
| allelopathic polyacetylenes fromcentaurea repens (russian knapweed). | the allelopathic weed russian knapweed (centaurea repens) was found to contain polyacetylenes viii-xiv in the roots. dose vs. response of the root length elongation against lettuce, alfalfa, barnyard grass, and red millet showed ix to be active. closely related isomers were not active. examination of the soil surrounding the russian knapweed roots revealed the presence of ix in sufficient concentration to have an appreciable effect on the surrounding plant community. | 1986 | 24307103 |
| low night temperature effect on photosynthate translocation of two c4 grasses. | translocation of assimilates in plants of echinochloa crus-galli, from quebec and mississippi, and of eleusine indica from mississippi was monitored, before and after night chilling, using radioactive tracing with the short-life isotope (11)c. plants were grown at 28°/22°c (day/night temperatures) under either 350 or 675 μl·l(-1) co2. low night temperature reduced translocation mainly by increasing the turn-over times of the export pool. e. crus-galli plants from mississippi were the most suscep ... | 1985 | 28311562 |
| isolation ofc-glycosylflavones as probing stimulant of planthoppers in rice plant. | three species of planthopper,nilaparvata lugens,sogatella furcifera, andlaodelphax striatellus, showed characteristic behavior of stylet probing in parenchymal tissues of plants. feeding experiments of planthoppers on aqueous sucrose solution containing the extract of rice plants or barnyard grass revealed the presence of the stimulant for the probing behavior in the plant tissues. eightc-glycosylflavones which stimulated stylet probing were isolated from rice plants. four of them were identifie ... | 1985 | 24310066 |
| phytotoxic properties of nordihydroguaiaretic acid, a lignan fromlarrea tridentata (creosote bush). | the phytotoxic properties of nordihydroguaiaretic acid (ndga) isolated from creosote bush,larrea tridentata (zygophyllaceae), were examined. ndga dramatically reduces the seedling root growth of barnyard grass, green foxtail, perennial ryegrass, annual ryegrass, red millet, lambsquarter, lettuce, and alfalfa, and reduces the hypocotyl growth of lettuce and green foxtail. it has no effect on the germination of lettuce seeds. ndga almost certainly contributes to the observed allelopathic nature of ... | 1985 | 24311094 |
| effects of temperature and co2 enrichment on kinetic properties of phospho-enol-pyruvate carboxylase in two ecotypes of echinochloa crus-galli (l.) beauv., a c4 weed grass species. | two populations of echinochloa crus-galli (québec, mississippi) were grown at the duke university phytotron under 2 thermoperiods (28°/22°c, 21°/15°c day/night) and 2 co2 regimes (350 and 675 μl l(-1)). thermostability, energy of activation (e a ),k m (pep), k m (mg(++)), and specific activity of phospho-enol-pyruvate carboxylase (pepc) were analyzed in partially purified enzyme preparations of plants grown for 5 weeks. thermostability of pepc from extracts (in vitro) and leaves (in situ) was si ... | 1984 | 28311006 |
| effects of temperature and co(2) enrichment on carbon translocation of plants of the c(4) grass species echinochloa crus-galli (l.) beauv. from cool and warm environments. | plants of echinochloa crus-galli from québec and mississippi were grown under two thermoperiods (28 degrees c/22 degrees c, 21 degrees c/15 degrees c) and two atmospheric co(2) concentrations (350 and 675 microliters per liter) to examine possible differential responses of northern and southern populations of this c(4) grass species. translocation was monitored using radioactive tracing with short-lived (11)c. co(2) enrichment induced a decrease in the size of the export pool in plants of both p ... | 1984 | 16663733 |
| somatic embryogenesis inechinochloa crusgalli. | a white, compact embryogenic tissue was obtained from young inflorescence segments ofechinochloa crusgalli (barnyard grass) cultured on murashige and skoog's medium containing various concentrations and combinations of 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine. histological and scanning electron microscopic studies revealed that the white compact callus contained embryoids in various stages of development. typical embryoids were bipolar and possessed scutella, coleoptiles and coleor ... | 1984 | 24253431 |
| development of photosynthetic activity following anaerobic germination in rice-mimic grass (echinochloa crus-galli var oryzicola). | shoots of anaerobically germinated echinochloa crus-galli var oryzicola are nonpigmented whether germinated in light or dark, and chlorophyll synthesis is minimal for the first 12 to 18 hours of greening after exposure to ambient conditions. when chlorophyll development is compared between greening anoxic and etiolated shoots, there is a 100-fold difference in chlorophyll levels at 8 hours, an 8-fold difference at 24 hours, but roughly equal amounts at 60 hours. the chlorophyll a/b ratio approac ... | 1983 | 16663217 |
| germination of echinochloa crus-galli (barnyard grass) seeds under anaerobic conditions : respiration and response to metabolic inhibitors. | echinochloa crus-galli l. beauv., a rice-field weed, can germinate and grow for extended periods of time in an anaerobic environment. compared to pea, which does not germinate under anaerobiosis, the evolution of co(2) in echinochloa and rice is lower and the peak rate of co(2) evolution is delayed when germinated without oxygen. the plants studied also differ with respect to their respiration ratio ([co(2)] n(2)/[co(2)] air) and metabolism used during the early stages of germination. echinochlo ... | 1983 | 16663086 |
| anaerobiosis in echinochloa crus-galli (barnyard grass) seedlings : intermediary metabolism and ethanol tolerance. | tolerance to ethanol and the ability to metabolize key intermediary substrates under anaerobiosis were studied in echinochloa crus-galli (l.) beauv. var oryzicola seeds to further characterize the mechanisms which enable it to germinate and grow without o(2).our results indicate that e. crus-galli var oryzicola possesses an inherently high tolerance to ethanol and is able to metabolize low levels of ethanol in the absence of o(2). concentrations of ethanol 45-fold greater than endogenous levels ... | 1983 | 16662979 |
| quantitative structure-activity relationships for 2-[(phenylmethyl)sulfonyl]pyridine 1-oxide herbicides. | phenyl-substituted analogues of 2-[(phenylmethyl)sulfonyl]pyridine 1-oxide preemergent herbicides were examined in order to determine quantitative relationships between structure and activity against the following three weed species: switch grass (panicum virgatum l.), barnyard grass (echinochloa crusgalli l. beauv.), and green foxtail (setaria viridis l. beauv.). analogues were chosen to provide maximum parameter orthogonality. regression analysis yielded structure-activity relationships wherei ... | 1983 | 6834380 |
| plastid development in seedlings of echinochloa crus-galli var. oryzicola under anoxic germination conditions. | plastid development in the primary leaf of echinochloa crus-galli (l.) beauv. var. oryzicola (vasing.) ohwi was followed during 5 d of anoxic germination and growth. plastids develop slowly from simple spheroidal proplastids into larger pleomorphic plastids with several stromal membranes and many peripheral membrane vesicles. a small prolamellar body is present at 96 h with perforated (pro)thylakoids extending into the stroma. changes in starch grains and plastoglobuli are evidence of carbohydra ... | 1982 | 24271619 |
| anaerobic metabolism in germinating seeds of echinochloa crus-galli (barnyard grass) : metabolite and enzyme studies. | echinochloa crus-galli, a problem weed in rice fields, has the rare ability to germinate and to grow in a totally oxygen-free environment. after 7 days growth in the light or dark under n(2), e. crus-galli var. oryzicola produces a 2- to 3-centimeter nonpigmented shoot.ethanol, malate, and lactate were measured in seeds germinated under n(2) and air, and compared with changes in the activities of alcohol dehydrogenase, malate dehydrogenase, nadp-malic enzyme, and phosphoenolpyruvate carboxylase. ... | 1981 | 16661863 |
| a mechanism of chlorosis caused by 1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-hydroxypyrazole, a herbicidal compound. | in organic solvents, 1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-hydroxypyrazole (dtp) converted chlorophyll a and b extracted from rice seedlings (oryza sativa l. ;kinmaze') into pheophytin a and b, respectively. on comparing the chlorophyll-converting activity of dtp to those of acetic, glycolic, 2,4-dichlorobenzoic, monochloroacetic, 2,6-dichlorobenzoic, pyruvic, and dichloroacetic acids, it was demonstrated that dtp induced h(+) into chlorophyll specifically. 5-hydroxypyrazoles, which seem to be ... | 1979 | 16661052 |
| [phytotoxicity of di,sec.butylamides of halogenoalkoxybenzoic acids]. | n,n-di,sec.butylamides of halogenated alkoxybenzoic acids were prepared and tested for phytotoxic activity. the corresponding acids and a series of n-alkyl- and n,n-dialkylamides of 2-methoxy-3,5-dichlorobenzoic acid were studied in parallel. the phytotoxicity of these substances was tested against seven representative weeds and some crop plants using both pre- and post-emergence test at doses of 6 kg/ha or lower. the amides studied proved more strongly phytotoxic on absorption through the root ... | 1978 | 738441 |
| the effect of atmospheric humidity on photosynthesis, transpiration and water use efficiency of leaves of several plant species. | the effect of humidity on the gas exchange of leaves of the dicotyledons soybean (glycine max (l.) merrill), sunflower (helianthus annuus l.), jojoba (simmondsia chinensis (l.) schneider), and saltbush (atriplex halimus l.) and the monocotyledons wheat (triticum aestivum l.), barley (hordeum vulgare l.) sorghum (sorghum bicolor (l.) moench) and barnyard grass (echinochloa crus-galli (l.) beauv.) was examined under conditions of adequate soil moisture in a controlled environment. photosynthesis a ... | 1977 | 24419571 |
| degradation and metabolism of drepamon in rice and barnyard grass. | | 2015 | 1002905 |
| heterodera graminophila n. sp. (nematoda heteroderae) from grass with a key to closely related species. | heterodera graminophila n. sp., a member of the h. goettingiana group, is described and illustrated from roots of barnyard grass, echinochloa colonum (l.) link, in baton rouge, la. this new abullate species, having second-stage larvae with only three lines in the lateral field, is most closely related to h. cyperi golden, rau &cobb, 1962, and h. graminis stynes, 1971, but differs particularly in having a small, inconspicuous anus without a circum-anal pattern and located about 20% of the cyst le ... | 1972 | 19319258 |