Search results for "Fagaceae"

RECOVERY AND CHARACTERIZATION OF THE CHESTNUT GERMPLASM ON THE WESTERN SLOPES OF THE ASPROMONTE IN SOUTHERN CALABRIA

2010

For a considerable period of time chestnuts were a fundamental source of food and economy for the people in the Aspromonte area. After decades in which chestnut cultivation has been neglected as a result of depopulation in mountainous zones, the production capacity in this area has reduced resulting in an erosion of the native germplasm. A survey has been carried out to improve the knowledge about the chestnut germplasm present in this area and to evaluate its qualities with the objective of preserving native genetic resources, safeguarding them from genetic erosion phenomenon and individuating local genotypes of market value which could be used to promote a re-launch of local chestnut cult…

Changes in the protein profile of Quercus ilex leaves in response to drought stress and recovery

2009

To characterize the molecular response of holm oak to drought stress and its capacity to recover 9-month-old Quercus ilex seedlings were subjected to three treatments for a 14-d period: (i) continuous watering to field capacity (control plants, W), (ii) no irrigation (drought treatment, D), and (iii) no irrigation for 7d followed by a watering period of 7d (recovery treatment, R). In drought plants, leaf water potential decreased from -0.72 (day 0) to -0.99MPa (day 7), and -1.50MPa (day 14). Shoot relative water content decreased from 49.3% (day 0) to 47.7% (day 7) and 40.8% (day 14). Photosystem II quantum yield decreased from 0.80 (day 0) to 0.72 (day 7) and 0.73 (day 14). Plants subjecte…

Biodiversità nella dendroflora italiana

2013

Nella flora vascolare indigena d’Italia, costituita da circa 7000 taxa specifici e infraspecifici, quelli arborei sono rappresentati da un modesto numero di unità. Tra gimnosperme e angiosperme non si superano 200 specie. Diversificano e arricchiscono la dendroflora italiana specie legnose policormiche o arbustive che, con l’età e in particolari condizioni, possono assurgere a veri e propri alberi. Vi contribuiscono anche espressioni genetiche di classiche specie arboree variamente interpretate a livello tassonomico. La dendroflora qui esaminata si riferisce a 53 generi (7 gimonosperme e 46 angiosperme). I taxa specifici e infraspecifici sono 188 (21 gimnosperme e 167 angiosperme). Non poch…

PAHs associated with the leaves of Quercus ilex L.: Extraction, GC–MS analysis, distribution and sourcesAssessment of air quality in the Palermo (Ita…

2007

Abstract In this study, the leaves of Quercus ilex L. were selected as possible bioaccumulators of polycyclic aromatic hydrocarbons (PAHs). Quercus is an evergreen plant that occurs widely in both urban and rural areas. Several sites (urban roadside, urban, urban park, suburban and rural) in and around Palermo city were investigated. The purpose of this research was to optimize analytical method for quercus leaves, investigate the degree of contamination in the urban area of Palermo by comparing PAH concentration in leaves of quercus from the several sites, establish distribution patterns and relate them to possible sources of PAHs. To this aim, the 16 recommended as priority pollutants by …

The combined effect of CO2, ozone, and drought on the radical scavenging system of young oak trees (Quercus petraea) — A phytothron study

1998

In order to study the combined effects of CO 2 , ozone, and drought, we simulated in a controlled environment the climatic conditions of a German oak stand with high ozone (daytime: 80 ppb, control: 20 ppb) during one vegetative period under a regime of low and high CO 2 concentration (370 vs 720 ppm) and drought (4 weeks < -800 hPa). To investigate the effects of CO 2 , ozone and drought on the radical scavenging system, we monitored the level of glutathione, ascorbate, and α-tocopherol. However, it is important that, under the regime of elevated CO 2 , the antioxidative behaviour of glutathione and ascorbate appears to be masked by their function as storage molecules for sulfur or carbon.

Foreed flushing of branch segments as a method for obtaining reactive explants of mature Quercus robur trees for micropropagation

1994

The aim of this study was to micropropagate mature Quercus robur L. trees when material retaining physiologically juvenile characteristics (stump sprouts, epicormic shoots) is not available. Branch segments from 70–300 year-old trees were force-flushed and the flushed, partially rejuvenated or reinvigorated shoots were used as a source of explants for establishment of cultures. In vitro establishment and multiplication was achieved with seven of the eight selected trees. The proliferation capacity of cultures of vertically placed explants declined after several subcultures, but efficient shoot multiplication was achieved by culturing decapitated shoots placed horizontally on GD medium suppl…

Differences of raw cork quality in productive cork oak woods in Sicily in relation to stand density

2010

Differences of raw cork quality, in terms of thickness and porosity, were observed in productive cork oak (Quercus suber L.) stands in the Nebrodi and Iblei mountains of Sicily in relation to stand density. Five study areas were chosen across a range of different stand density satisfying specific sampling requirements among two managed cork oak stands. Analysis of variance using Fisher-Snedecor's F test (p<0,05) were used to identify statistically significant differences of cork quality and sylvicultural, dendrometric and cork stripping parameters between study areas within each stand and also between stands. Relationships between cork quality and sylvicultural and dendrometric parameters w…

Microbial Community Structure and Density Under Different Tree Species in an Acid Forest Soil (Morvan, France)

2005

Overexploitation of forests to increase wood production has led to the replacement of native forest by large areas of monospecific tree plantations. In the present study, the effects of different monospecific tree cover plantations on density and composition of the indigenous soil microbial community are described. The experimental site of "Breuil-Chenue" in the Morvan (France) was the site of a comparison of a similar mineral soil under Norway spruce (Picea abies), Douglas fir (Pseudotuga menziesii), oak (Quercus sessiflora), and native forest [mixed stand dominated by oak and beech (Fagus sylvatica)]. Sampling was performed during winter (February) at three depths (0-5, 5-10, and 10-15 cm…

Structural studies of the hemicellulose A from the cork of Quercus suber

1987

Brenneria quercina and Serratia spp. isolated from Spanish oak trees Molecular characterization and development of PCR primers

2008

Brenneria quercina has been reported as one of the causal agents of oak decline in Spain. To investigate the bacterial variability of this pathogen from different Spanish oak forests, a collection of 38 bacterial isolates from seven geographic locations and from different oak species was analysed by sequencing 16S rDNA and rep-PCR fingerprinting. All Spanish isolates of B. quercina were grouped by rep-PCR into a homogenous cluster that differed significantly from B. quercina reference strains from California. 16S rDNA analysis revealed that 34 out of 38 isolates were Brenneria. However, four isolates belonged to the genus Serratia, suggesting that this bacterium could cause cankers in oak t…