Search results for "Juniperus"
showing 10 items of 19 documents
Effects on Arterial Blood Pressure of Methanol and Dichloromethanol Extracts fromJuniperus oxycedrus L.
1997
The present study analysed the effect of the methanol and dichloromethanol extracts from Juniperus oxycedrus on arterial blood pressure in anaesthetized rats. The arterial blood pressure of normotensive rats was significantly reduced by the i.v. administration of both extracts. The hypotensive effect of these extracts was independent of the adrenergic system. These results may explain the vasorelaxing actions observed in other Juniperus species.
Axillary shoot proliferation in cultures of explants from mature Juniperus oxycedrus trees.
1995
We developed procedures for the micropropagation of Juniperus oxycedrus L. using shoot apices or nodal segments from mature plants. Of the media and explants examined, best culture establishment was obtained with shoot apices cultured on modified Schenk and Hildebrandt medium (SH medium) without growth regulators; however, shoot multiplication was only achieved when shoot apices isolated from shoots grown on SH medium without growth regulators were subcultured on SH medium containing 0.5 micro M benzyladenine. None of the auxins and methods tested for root induction provided satisfactory results.
An Ecohydrological Cellular Automata Model Investigation of Juniper Tree Encroachment in a Western North American Landscape
2016
Woody plant encroachment over the past 140 years has substantially changed grasslands in western North American. We studied encroachment of western juniper (Juniperus occidentalis var. occidentalis) into a previously mixed shrubâgrassland site in central Oregon (USA) using a modified version of Cellular Automata TreeâGrassâShrub Simulator (CATGraSS) ecohydrological model. We developed simple algorithms to simulate three encroachment factors (grazing, fire frequency reduction, and seed dispersal by herbivores) in CATGraSS. Local ecohydrological dynamics represented by the model were first evaluated using satellite-derived leaf area index and measured evapotranspiration data. Reconstruc…
Changes in land use and physiological transitions of a Juniperus thurifera forest: from decline to recovery
2015
All Rights Reserved. Forest decline is frequently associated with infection; however, infections habitually affect trees that have been previously debilitated by environmental stress. Nevertheless, the causes and physiology of noninfectious forest decline are not well known. Some Juniperus thurifera L. forests presented severe (noninfectious) declines, with defoliations over 50%. The goal of this study was to determine the causes and characterize the physiology of this noninfectious decline, and we hypothesized that it could be related to environmental stress from increasing interspecific competition resulting from land abandonment. We randomly assigned60 trees to either a control group or …
Heteroptera of Lebanon. II.Phytocoris(Exophytocoris)RaunolinnavuoriiSp. Nov. from the Horsh Ehden Nature Reserve and Adjacent Areas (Hemiptera: Heter…
2016
Abstract A new species of Phytocoris (Heteroptera: Miridae: Mirinae: Mirini), P. (Exophytocoris) raunolinnavuorii sp. nov., is described and illustrated from Lebanon. The new species, easily distinguished from all the other species of the subgenus by its coloration and male genitalia, belongs to the Phytocoris pinihalepensis-group. The new species lives on the conifers Abies cilicica (Antoine & Kotschy) Carriere (Pinaceae) and Juniperus excelsa M. Bieb. (Cupressaceae).
Factors controlling adventitious bud induction and plant regeneration in matureJuniperus oxycedrus leaves cultured in vitro
1994
The morphogenetic capacity of matureJuniperus oxycedrus L. leaves cultured in vitro has been studied, noting nutritive, hormonal, and environmental factors inducing differentiation and development of adventitious shoots. Bud primordia formed directly from the leaves. Highest bud differentiation rates were obtained when the explants were cultured for at least 21 days on a modified Schenk and Hildebrandt solidified medium containing 0.5 μM benzyladenine under a 16-h photoperiod. Maximum bud development and elongation was achieved on cytokinin-free medium containing 4% (wt/vol) sucrose and 0.05% (wt/vol) activated charcoal. Regenerated shoots were excised and induced to root on media with auxi…
Epiphytic bryophytes in harsh environments: theJuniperus thuriferaforests
2010
SUMMARY The forests of Juniperus thurifera are peculiar ecosystems that typically grow on mountains and highplateaux of the western Mediterranean basin with dry and continental climates. Some previous surveys suggested that these forests house a rather distinctive epiphytic bryophyte flora. Epiphytic bryophyte communities were systematically sampled in 19 representative juniper forests, for the first time spanning all the distribution area of this conifer. The flora consists of 44 species (32 acrocarpous mosses, 10 pleurocarpous mosses and 2 liverworts). Orthotrichum species are the most frequent and abundant in most of the sampled localities, including some uncommon taxa such as Orthotrich…
Phytochemical Analysis and Cytotoxicity Towards Multidrug-Resistant Leukemia Cells of Essential Oils Derived from Lebanese Medicinal Plants
2012
Juniperus excelsa fruit essential oil as well as J. oxycedrus, Cedrus libani, and Pinus pinea wood essential oils have been obtained with yields between 2.2 ± 0.3 % to 3.4 ± 0.5 % and analyzed by gas chromatography. Sesquiterpenes mainly characterized C. libani and J. oxycedrus essential oils, while in P. pinea and J. excelsa, monoterpenes were the most abundant compounds. In J. oxycedrus, cis-calamenene (7.8 %), cuparene (3.8 %), and cis-thujopsenal (2.0 %) have been detected for the first time. The cytotoxic activity of these essential oils against drug-sensitive CCRF-CEM and multidrug-resistant P-glycoprotein-expressing CEM/ADR5000 leukemia cells has been investigated (IC₅₀ values: 29.46…
Different parts of the same plants. Charcoals and seeds from Cova de les Cendres (Alicante, Spain)
2018
Abstract The analysis of archaeobotanical macroremains from Cova de les Cendres (Teulada-Moraira, Alicante, Spain) allows a better understanding of the dynamic of the vegetation during the Upper Palaeolithic in the region. The anthracological sequence shows that Pinus type nigra/sylvestris dominates in the area during the Upper Palaeolithic, while more open formations of Juniperus and Fabaceae spread in Upper Solutrean and Early-Middle Magdalenian. The carpological analysis that has been carried out in the Middle Magdalenian level has brought to light different species of Juniperus (J. sabina, J. communis and J. oxycedrus). This information indicates that during the period, Cova de les Cend…
Bioactive Constituents of Juniperus turbinata Guss. from La Maddalena Archipelago.
2018
A comprehensive phytochemical study of Juniperus turbinata (Cupressaceae) collected from La Maddalena Archipelago (Sardinia, Italy) is reported. Both the essential oil and the ethanolic extract obtained from the aerial parts were analyzed. The essential oil appears to belong to a new chemotype compared to other Mediterranean juniper accessions, as it was favored by geographic isolation of the isles. It showed a low content of monoterpene hydrocarbons and -terpineol, ent-manoyl oxide, 1,10-di-epi-cubenol as the major constituents. The ethanolic fraction contained mainly diterpenoids. Among these, 15-formyloxyimbricatolic acid (7) is a new natural product since it has hitherto been obtained o…