GALLOTANNINS FROM QUERCUS ROBUR CULTIVATED IN EGYPT

1998 ◽  
Vol 21 (1) ◽  
pp. 1-6
Author(s):  
Salwa Farag ◽  
Nasr El-Emary ◽  
Masatake Niwa
Keyword(s):  
Quercus Robur

A comparative study of the antibacterial activity of Quercus robur (Ethanolic extract) and Zinc oxide nanoparticles on Salmonella (In vitro)

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Hams H. H. Alfattli ◽  
Ghufran Zuhair Jiber ◽  
Ghaidaa Gatea Abbass
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Zinc Oxide Nanoparticles ◽  
Quercus Robur ◽  
Ethanolic Extract ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Oxide Nanoparticles ◽  
Inhibition Zones

This study which designed to evaluate the inhibitory effect of Ethanolic extract of (Quercusrobur) and Zinc oxide nanoparticles on the growth of one genus of enterobacteriacae (Salmonella). In vitro. For this purpose graduate concentrates for plant extract (50, 100, 200, 400 )mg/ml which prepared and compared with Zinc oxide nanoparticles of different concentration (2, 1, 0.5, 0.25) μg/ml,and examined. The result showed that the studied medicinal plant has antibacterial activity against this bacteria which used. The result showed that the plant has good activity in decrease the growth of this bacteria. The results of the study also showed that the nano-ZnO has very effective antibacterial action against the studied bacteria which was Salmonella,nanoparticles concentrations lead to increasing in the inhibition zones of tested bacterial growth. We also study the effect of three antibiotics Lomefloxacin (LOM), Ciprofloxacin (SIP) and Rifampin (RA) and the result showed,in a comparison within the tested bacteria,Salmonella had a significant inhibition increase in Lomefloxacin ; the ciprofloxacin showed effect on tested bacteria. However,Rifampin does not show any effect on tested bacteria.

The In vitro Evaluation of the Antimicrobial Activity of Quercus robur L. Methanolic and Aqueous Leaves’ Extracts, from the Algerian High Plateaus Against some Uropathogenic Microbial Strains

2019 ◽  
Vol 18 (5) ◽  
pp. 262-274
Author(s):  
E. Benyagoub ◽  
N. Nabbou ◽  
S. Boukhalkhel ◽  
I. Dehini
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Enterococcus Faecalis ◽  
Fusidic Acid ◽  
Quercus Robur ◽  
Diffusion Method ◽  
Phytochemical Analysis ◽  
Microbial Strains

The medicinal value of the plants is due to their chemical components that bring a definite physiological action on the human body to prevent the diseases. In this work, we investigated the antimicrobial activity of leaves’ extracts of Quercus robur L., collected from the Algerian upper highlands, on ten bacterial strains and one fungal strain known to be pathogenic. First, we performed a qualitative phytochemical analysis, and second, antimicrobial activity tests performed by agar diffusion method (disc and well) with the determination of MIC by broth macro-dilution method. Given the results, it appears that obtained macerates of Quercus robur L. were rich in bioactive phytoconstituents such as alkaloids, anthraquinones, saponins, tannins, and other components. The yield of aqueous and methanolic macerates of leaves was 8.5 ± 1.41 and 22.4 ± 4.36%, respectively. The bacterial resistance was relatively important to several antibiotics, namely, ampicillin, amoxicillin + clavulanic acid for strains of Escherichia coli and Salmonella sp. However, Staphylococcus aureus strains were resistant to fusidic acid, penicillin, and oxacillin; while Enterococcus faecalis was resistant to fusidic acid, penicillin, oxacillin, and ticarcillin. The antibacterial activity of the macerates toward tested microbial strains showed that the aqueous and methanolic macerates of the leaves were proportional to the tested concentration and active not only against Gram-positive and Gram-negative bacteria but also on the fungal species Candida albicans. The estimated MIC for Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus was in the order of 10 mg/mL, which seems more effective than toward Salmonella sp., Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans which were in the order of 30 mg/mL. These preliminary results confirm that the part of the studied plant had a very good antimicrobial activity that was proportional to the serial concentrations of the tested extracts.

Potenzielle Eichenwuchsgebiete und aktuelle Eichenmischwälder der Schweiz | Potential oak sites and actual mixed oak forests in Switzerland

2008 ◽  
Vol 159 (5) ◽  
pp. 103-111
Author(s):  
Urs Mühlethaler ◽  
Yvonne Reisner ◽  
Nele Rogiers
Keyword(s):  
Information System ◽  
Quercus Robur ◽  
Geographical Information ◽  
Oak Forests ◽  
Natural Growth ◽  
Growth Area ◽  
Entire Country ◽  
Middle Spotted Woodpecker ◽  
Evaluation Matrix ◽  
Common Oak

On behalf of the Federal Office for the Environment (FOEN), the Swiss College for Agriculture established the basis to foster oak species in Switzerland. For this, the growth areas of three oak species, common oak (Quercus robur), sessile oak (Q. petraea) and pubescent oak (Q. pubescens) were assessed throughout the entire country. The assessment was based on their physiological potential, their natural growth area and on the appearance of the middle spotted woodpecker. In addition, the older mixed oak stands were surveyed. These fundamental data were collected with a geographical information system and analyzed for each canton. Altogether, approximately one-fourth of the Swiss forest area is suitable for oak. The natural oak growth area covers however 38 500 ha only. About 19 000 ha of forest are populated by the middle spotted woodpecker and extended older mixed oak forests are found on approximately 24 500 ha. According to the applied evaluation matrix, the greatest potential for fostering oak species lies in eight cantons: Aargau, Zürich, Solothurn, Thurgau, Vaud, BaselLandschaft, Ticino and Schaffhausen.

The resistance of the phenological forms of the common oak (Quercus robur L.) to unfavorable external factors

2017 ◽  
Author(s):  
И.А. Уткина ◽  
В.В. Рубцов
Keyword(s):  
Quercus Robur ◽  
Insect Pests ◽  
Weather Conditions ◽  
External Factors ◽  
Individual Species ◽  
Early Form ◽  
The Common ◽  
Spring Frosts ◽  
Common Oak ◽  
Late Form

Ранняя (Quercus robur var. praecox Czern.) и поздняя (Q. robur var. tardiflora Czern.) фенологические формы дуба черешчатого, выделенные в самостоятельные таксоны в середине XIX в., неоднократно становились объектами исследований для специалистов разного профиля. Собрано немало данных о различиях в их росте, требованиях к условиям местообитания, устойчивости к неблагоприятным внешним факторам. Иногда кроме ранней и поздней феноформ выделяют еще и промежуточные между ними. Наиболее отчетливо различия между феноформами, обусловленные разными сроками листораспускания, проявляются в реакции на поздние весенние заморозки и повреждение листвы насекомыми-филлофагами. Так как на деревьях поздней формы листовые и цветочные почки раскрываются намного позже, чем на ранней, поздняя форма избегает повреждения весенними заморозками. Кроме того, обладая меньшей способностью к формированию летних побегов, она меньше повреждается и ранними осенними заморозками, а также зимними морозами, что способствует образованию у нее более прямых и полнодревесных стволов, по сравнению с ранней формой. Ранняя форма чаще и сильнее повреждается филлофагами ранневесеннего комплекса, у которых отрождение гусениц из яиц синхронизировано с раскрытием почек и распусканием листьев. Есть данные, что видовой состав вредителей листвы на деревьях ранней и поздней форм дуба при их совместном произрастании примерно одинаков, зато численность отдельных видов филлофагов и их соотношение различны. На деревьях ранней формы их больше в несколько раз, что объясняется совпадением фаз развития большинства ранневесенних видов филлофагов и листвы этой формы дуба. Согласно результатам проведенных исследований, поздняя форма предпочтительнее для создания лесных культур дуба как более устойчивая к неблагоприятным погодным условиям и насекомым-вредителям. Early (Quercus robur var. praecox Czern.) and late (Q. robur var. tardiflora Czern.) phenological forms of the common oak, recognized as independent taxa in the mid-nineteenth century, have been subjects of multiple studies by specialists of different fields. Abundant data on the differences in their growth requirements, habitat conditions, and resistance to unfavorable external factors have been collected. Some specialists in addition to early and late phenoforms distinguish intermediate forms. Most clearly the differences between these forms appear in response to late spring frosts and damage of leaves by phyllophagous insects due to different timing of the forms' leafing. As leaf and flower buds in late oaks are revealed much later than in early oaks, late form avoids damage by spring frosts. In addition, due to lower ability to form summer shoots, late oaks are less damaged by early autumn frosts and winter freeze, which contributes to the formation of more straight and full trunks comparing to early oaks. Early oaks are damaged more severely by phyllophagous insects of spring complex, in which hatching of caterpillars from eggs is synchronized with opening buds and unfolding of leaves. There is evidence that species composition of foliage pests on co-occurant early and late forms of oak is nearly the same, but the number of individual species of phyllophagous insects and their ratio are different. In the early form the number of phyllophagous insects is greater by several fold due to concurrence of developmental phases in most early spring phyllophagous species and foliage of this oak form. The obtained results show that the late form of common oak is preferable for forest plantations as more resistant to unfavorable weather conditions and insect pests.

Scaling leaf photosynthesis to canopy in a mixed deciduous forest. I. model description

1997 ◽  
Vol 62 ◽  
Author(s):  
R. Samson ◽  
S. Follens ◽  
R. Lemeur
Keyword(s):  
Temperature Dependence ◽  
Quercus Robur ◽  
Deciduous Forest ◽  
Growing Season ◽  
Model Description ◽  
Canopy Photosynthesis ◽  
Leaf Photosynthesis ◽  
Layer Model ◽  
Mixed Deciduous Forest ◽  
Leaf Level

A  multi-layer model (FORUG) was developed, to simulate the canopy  photosynthesis of a mixed deciduous forest during the growing season.  Measured photosynthesis parameters, for beech (Fagus  sylvatica), oak (Quercus  robur) and ash (Fraxinus  excelsior), were used as input to the model. This  information at the leaf level is then scaled up to the level of the canopy,  taking into account the radiation profiles (diffuse and direct PAR) in the  canopy, the vertical LAI distribution, the evolution of the LAI and the  photosynthesis parameters during the growing season, and the temperature  dependence of the latter parameters.

Growth and management of mixed Pinus sylvestris - Quercus robur stands in Flanders, Belgium

1993 ◽  
Vol 58 ◽  
Author(s):  
D. Maddelein ◽  
J. Neirynck ◽  
G. Sioen
Keyword(s):  
Pinus Sylvestris ◽  
Natural Regeneration ◽  
Quercus Robur ◽  
Good Growth ◽  
Pedunculate Oak ◽  
Selection System ◽  
Management Options ◽  
Stand Management ◽  
Pine Stands

Mature  Scots pine (Pinus sylvestris  L.) stands are dominating large parts of the Flemish forest area. Broadleaved  species regenerate spontaneously under this pine canopy. This study studied  the growth and development of two planted pine stands with an older natural  regeneration, dominated by pedunculate oak (Quercus  robur L.), and discussed management options for  similar stands.     The results indicated a rather good growth of the stands, with current  annual increments of 5 m3.ha-1.yr-1. The pine overstorey is growing into valuable sawwood  dimensions, while the broadleaved understorey slowly grows into the  upperstorey. The quality of the regeneration is moderate but can be improved  by silvicultural measurements (pruning, early selection).     In both stands, an interesting (timber production, nature conservation)  admixture of secondary tree species is present in the regeneration. Stand  management is evolving from the classical clearcut system towards a  combination of a type of selection and group selection system.

scholarly journals Ectomycorrhiza resilience and recovery to extreme flood events in Tuber aestivum and Quercus robur

Mycorrhiza ◽  
2021 ◽  
Author(s):  
P. W. Thomas
Keyword(s):  
Climate Change ◽  
Seedling Growth ◽  
Quercus Robur ◽  
Root Systems ◽  
Fruiting Bodies ◽  
Flood Events ◽  
Tuber Aestivum ◽  
Soil Zone ◽  
Extreme Flood ◽  
The Impact

AbstractVery little is known about the impact of flooding and ground saturation on ectomycorrhizal fungi (EcM) and increasing flood events are expected with predicted climate change. To explore this, seedlings inoculated with the EcM species Tuber aestivum were exposed to a range of flood durations. Oak seedlings inoculated with T. aestivum were submerged for between 7 and 65 days. After a minimum of 114-day recovery, seedling growth measurements were recorded, and root systems were destructively sampled to measure the number of existing mycorrhizae in different zones. Number of mycorrhizae did not display correlation with seedling growth measurements. Seven days of submersion resulted in a significant reduction in mycorrhizae numbers and numbers reduced most drastically in the upper zones. Increases in duration of submersion further impacted mycorrhizae numbers in the lowest soil zone only. T. aestivum mycorrhizae can survive flood durations of at least 65 days. After flooding, mycorrhizae occur in higher numbers in the lowest soil zone, suggesting a mix of resilience and recovery. The results will aid in furthering our understanding of EcM but also may aid in conservation initiatives as well as providing insight for those whose livelihoods revolve around the collection of EcM fruiting bodies or cropping of the plant partners.

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