Search results for "allelopathy"
showing 8 items of 18 documents
Herbicidal activity of Mediterranean essential oils and their effects on soil bioindicators.
2020
[ES] Las preocupaciones ambientales y de salud han estimulado el interés en estrategias alternativas para el manejo de las malas hierbas. En todo el mundo se están haciendo esfuerzos para reducir la gran dependencia de los herbicidas sintéticos que se utilizan como principal método para el control de las plantas arvenses. Los herbicidas naturales basados en sustancias alelopáticas, como los aceites esenciales (AEs) extraídos de plantas, se han sugerido como una de las posibles alternativas para lograr un manejo sostenible de las arvenses. Por un lado, los AEs han mostrado capacidad para inhibir la germinación y el crecimiento de semillas de malas hierbas, por otro lado, hay una falta de est…
Phytotoxic Lignans from Artemisia arborescens
2018
A systematic bioassay-guided fractionation of methylene chloride extracts of the aerial part of Artemisia arborescens was performed in order to identify its phytotoxic compounds Two lignans were isolated, sesamin and ashantin, that inhibited growth of Agrostis stolonifera (bentgrass), a monocot, and Lactuca sativa (lettuce), a dicot, at 1 mg mL–1. In a dose-response screening of these lignans for growth inhibition against Lemna paucicostata (duckweed), ashantin was the most active with an IC50 of ca. 224 μM. The mode of action of these compounds is still unknown. In mosquito larvicidal bioassays the pure compounds sesamin and ashantin did not cause mortality at the highest dose of 125 mg/L…
Essential Oils of Chiliadenus Lopadusanus (Asteraceae)
2013
The essential oils from the leaves and flowers of Chiliadenus lopadusanus growing on Lampedusa Island were obtained by hydrodistillation and analyzed by GC-MS. The major component was camphor (39.4% in the leaves and 24.0% in the flowers), followed in the leaves by torreyol (6.7%), t-cadinol (5.2%) and 1,8-cineole (3.8%), while in the flowers by t-cadinol (15.2%), t-muurolol (5.1%) and torreyol (4.5%). Among the compounds identified, several seem to play a role in antibacterial, antifungal, allelopathic and spasmolytic activity. In addition, several compounds identified in this study seem to influence the attraction of Megachile ( Eutricharaea) apicalis (Megachilidae) and Halictus ( Selado…
Crotonic acid as a bioactive factor in carrot seeds (Daucus carota L.)
2004
Water extracts from the carrot seed (Daucus carota L.) var. Perfekcja exhibit plant growth inhibitory properties against cress, cucumber, onion and carrot in a dose-dependant manner. This property results from the action of low-and high-molecular components of the extract. The low-molecular component was identified as crotonic acid ((E)-2-butenoic acid). Its presence was also confirmed in other late varieties of carrot. The determined strong herbicidal properties of crotonic acid and its availability after release to soil combined with its high level in seeds suggest that it might be considered as an allelopathic and autotoxic factor in the seeds.
Allelopatyczne właściwości metabolitów wtórnych roślin uprawnych
2009
Allelopathy has been defined by the International Allelopathy Society as "any process involving secondary metabolites produced by plants, microorganisms, viruses and fungi that influence the growth and development of agricultural and biological systems, including positive and negative effects [1]". Allelochemicals can be released into the environment and despite what effect they evoke towards living organisms this kind of specific chemical interactions is known as "allelopathy". Allelopathic phenomena have been observed and studied from ancient times. Theophrastus from Eresos, a disciple of Aristotle, reported an inhibitory effect of pigweed Polygonum spp. on alfalfa in ca. 350 B.C., wherea…
Phytotoxic effects of Lantana camara, Eucalyptus camaldulensis and Eriocephalus africanus essential oils in weeds of Mediterranean summer crops
2009
Abstract The essential oil composition of Lantana camara , Eucalyptus camaldulensis and Eriocephalus africanus was analyzed by means of GC and GC–MS and bioassayed in order to determine their activity against Amaranthus hybridus and Portulaca oleracea . E. camaldulensis essential oil, with spathulenol as the main compound, was the most effective, completely inhibiting germination and seedling growth on both weeds. The essential oil of E. africanus , rich in artemisia ketone, showed activity similar to that of E. camaldulensis on A. hybridus , but it was not so effective against P. oleracea , and L. camara essential oil, with high percentages in sesquiterpene hydrocarbons, also showed higher…
Potential allelopathic activity ofSideritis italica(Miller) Greuter et Burdet essential oil
2011
Sideritis italica (Miller) Greuter et Burdet is a widespread Mediterranean Lamiacea. Essential oils from S. italica flowerheads and leaves were extracted by hydrodistillation and then tested for their potential allelopathic activity against Raphanus sativus L. (Magnoliophyta) and the moss Tortula muralis (Hedw.) (Bryophyta), two organisms already tested for allelopathy, and against two bryophytes growing in the same environment as S. italica: the moss Bryum capillare Hedw. and the liverwort Lunularia cruciata (L.) Dum. For R. sativus, we considered seed germination and root and epicotyl growth. For the mosses, we used spore germination and protonemata development, while for the liverwort, w…
Composition and allelopathic effect of essential oils of two thistles: Cirsium creticum (Lam.) D.�Urv. ssp. triumfetti (Lacaita) Werner and Carduus n…
2007
Abstract Cirsium and Carduus are two of the main genera of true thistles. Different species in these genera share a quantity of secondary metabolites and have interesting ecological properties. The essential oils of two species, Cirsium creticum and Carduus nutans, were analysed, showing the presence as main compounds of 4-ethyl guaiacol (15%), hexadecanoic acid (10.6%), (E)-β-damascenone (7.8%), dihydroactinidiolide (6.0%) and 4-vinyl guaiacol (4.5%) for C. creticum and hexadecanoic acid (18.6%), hexahydrofarnesylacetone (7.8%), heptacosane (5.9%), 4-vinyl guaiacol (5.8%), pentacosane (3.8%) and eugenol (3.6%) for C. nutans. The oils were evaluated at different doses for their effect on ge…