<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cheaib, Alissar</style></author><author><style face="normal" font="default" size="100%">Badeau, Vincent</style></author><author><style face="normal" font="default" size="100%">Boe, Julien</style></author><author><style face="normal" font="default" size="100%">Chuine, Isabelle</style></author><author><style face="normal" font="default" size="100%">Delire, Christine</style></author><author><style face="normal" font="default" size="100%">Dufrêne, Eric</style></author><author><style face="normal" font="default" size="100%">François, Christophe</style></author><author><style face="normal" font="default" size="100%">GRITTI, EMMANUEL S</style></author><author><style face="normal" font="default" size="100%">Legay, Myriam</style></author><author><style face="normal" font="default" size="100%">Pagé, Christian</style></author><author><style face="normal" font="default" size="100%">Thuiller, Wilfried</style></author><author><style face="normal" font="default" size="100%">Viovy, Nicolas</style></author><author><style face="normal" font="default" size="100%">Leadley, Paul</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Climate change impacts on tree ranges: model intercomparison facilitates understanding and quantification of uncertainty</style></title><secondary-title><style face="normal" font="default" size="100%">Ecology Letters</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Fagus sylvatica</style></keyword><keyword><style  face="normal" font="default" size="100%">France</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus sylvestris</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus petraea</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus robur</style></keyword><keyword><style  face="normal" font="default" size="100%">species range</style></keyword><keyword><style  face="normal" font="default" size="100%">vegetation model intercomparison</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Publishing Ltd</style></publisher><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">533-544</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Ecology Letters (2012) Abstract Model-based projections of shifts in tree species range due to climate change are becoming an important decision support tool for forest management. However, poorly evaluated sources of uncertainty require more scrutiny before relying heavily on models for decision-making. We evaluated uncertainty arising from differences in model formulations of tree response to climate change based on a rigorous intercomparison of projections of tree distributions in France. We compared eight models ranging from niche-based to process-based models. On average, models project large range contractions of temperate tree species in lowlands due to climate change. There was substantial disagreement between models for temperate broadleaf deciduous tree species, but differences in the capacity of models to account for rising CO2 impacts explained much of the disagreement. There was good quantitative agreement among models concerning the range contractions for Scots pine. For the dominant Mediterranean tree species, Holm oak, all models foresee substantial range expansion.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pereira, Paulo</style></author><author><style face="normal" font="default" size="100%">Úbeda, Xavier</style></author><author><style face="normal" font="default" size="100%">Martin, Deborah</style></author><author><style face="normal" font="default" size="100%">Mataix-Solera, Jorge</style></author><author><style face="normal" font="default" size="100%">Guerrero, César</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the northeast of the Iberian Peninsula.</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Ash</style></keyword><keyword><style  face="normal" font="default" size="100%">iberian peninsula</style></keyword><keyword><style  face="normal" font="default" size="100%">Prescribed fire</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus robur</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><volume><style face="normal" font="default" size="100%">111</style></volume><pages><style face="normal" font="default" size="100%">237-247</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO(2)) and total sulphur (TS). A prescribed fire was conducted in a cork oak (Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40×70m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC (p&lt;0.001), water-soluble Ca, Mg, Na, SiO(2) and TS and a decrease in water-soluble Mn, Fe and Zn. Differences were identified between oak species for water-soluble K, Al and Fe. In Q.S samples we registered a significant increase in the first two elements p&lt;0.001 and p&lt;0.01, respectively, and a non-significant impact in the third, at p&lt;0.05. In Q.R data we identified a non-significant impact on water-soluble K and Al and a significant decrease in water-soluble Fe (p&lt;0.05). These differences are probably due to vegetation characteristics and burn severity. The fire induced a higher variability in the ash soluble elements, especially in Q.S samples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity prescribed fire will improve soil nutrient status without causing soil degradation and thus is considered to be a good management strategy.</style></abstract><accession-num><style face="normal" font="default" size="100%">20869047</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Daas, C.</style></author><author><style face="normal" font="default" size="100%">Montpied, P.</style></author><author><style face="normal" font="default" size="100%">Hanchi, B.</style></author><author><style face="normal" font="default" size="100%">Dreyer, E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Responses of photosynthesis to high temperatures in oak saplings assessed by chlorophyll-a fluorescence: inter-specific diversity and temperature-induced plasticity</style></title><secondary-title><style face="normal" font="default" size="100%">Annals of forest science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">optimal temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Photochemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">quantum yield</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus canariensis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus coccifera</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus petraea</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus robur</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.afs-journal.org/articles/forest/abs/2008/03/f07131/f07131.html</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">65</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">• The sensitivity of photosynthesis to high temperature was investigated in greenhouse-grown saplings of three Mediterranean (Quercus canariensis Willd., Q. coccifera L. and Q. suber L.) and two temperate European oak species (Q. robur L. and Q. petraea Matt. Liebl.). The sensitivity to high temperature was inferred from F0T curves producing the critical temperature (Tc ) at which a rapid rise in ground chlorophyll a ﬂuorescence (F0) occurs. Tc is known to acclimate to moderately increased ambient temperature by displaying signiﬁcant increases. • We ﬁrst checked whether acclimation of Tc was paralleled by an increase in optimal temperature for light driven electron ﬂux (Topt ,), recorded by measuring quantum yield of photochemistry under saturating CO2 and moderate irradiance. Saplings of Q. suber and Q. canariensis were submitted to four, ﬁve days long ambient temperature steps (15, 25, 35 and 15 ◦ C again). Tc was usually largely above 45 ◦ C while Topt was around 30–35 ◦ C. Both increased with ambient temperature in the two species, and decreased again when temperature returned to the initial values. This recovery was nevertheless not complete after a week at 15 ◦ C. • A second experiment tested whether the plasticity of Tc was of the same extent in the ﬁve species. A signiﬁcant increase of Tc followed by a decrease was detected in all species. Only small inter-speciﬁc diﬀerences were detected in Tc , and temperature induced plasticity was similar in the diﬀerent species: Tc increased by about 4–5 ◦ C while ambient temperature was increased from 15 to 35 ◦ C. Mediterranean and European oaks did not diﬀer in this respect. • This result does not support the hypothesis that oak species from warmer regions would display a larger plasticity of Tc in response to increasing temperatures.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Daas, C</style></author><author><style face="normal" font="default" size="100%">Montpied, P</style></author><author><style face="normal" font="default" size="100%">Hanchi, B</style></author><author><style face="normal" font="default" size="100%">Dreyer, E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Responses of photosynthesis to high temperatures in oak saplings assessed by chlorophyll-a fluorescence: inter-specific diversity and temperature-induced plasticity</style></title><secondary-title><style face="normal" font="default" size="100%">Annals of forest science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">optimal temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Photochemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">quantum yield</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus canariensis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus coccifera</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus petraea</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus robur</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><volume><style face="normal" font="default" size="100%">65</style></volume><pages><style face="normal" font="default" size="100%">305</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">• The sensitivity of photosynthesis to high temperature was investigated in greenhouse-grown saplings of three Mediterranean (Quercus canariensis Willd., Q. coccifera L. and Q. suber L.) and two temperate European oak species (Q. robur L. and Q. petraea Matt. Liebl.). The sensitivity to high temperature was inferred from F0T curves producing the critical temperature (Tc ) at which a rapid rise in ground chlorophyll a ﬂuorescence (F0) occurs. Tc is known to acclimate to moderately increased ambient temperature by displaying signiﬁcant increases. • We ﬁrst checked whether acclimation of Tc was paralleled by an increase in optimal temperature for light driven electron ﬂux (Topt ,), recorded by measuring quantum yield of photochemistry under saturating CO2 and moderate irradiance. Saplings of Q. suber and Q. canariensis were submitted to four, ﬁve days long ambient temperature steps (15, 25, 35 and 15 ◦ C again). Tc was usually largely above 45 ◦ C while Topt was around 30–35 ◦ C. Both increased with ambient temperature in the two species, and decreased again when temperature returned to the initial values. This recovery was nevertheless not complete after a week at 15 ◦ C. • A second experiment tested whether the plasticity of Tc was of the same extent in the ﬁve species. A signiﬁcant increase of Tc followed by a decrease was detected in all species. Only small inter-speciﬁc diﬀerences were detected in Tc , and temperature induced plasticity was similar in the diﬀerent species: Tc increased by about 4–5 ◦ C while ambient temperature was increased from 15 to 35 ◦ C. Mediterranean and European oaks did not diﬀer in this respect. • This result does not support the hypothesis that oak species from warmer regions would display a larger plasticity of Tc in response to increasing temperatures.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Morin, Xavier</style></author><author><style face="normal" font="default" size="100%">Améglio, Thierry</style></author><author><style face="normal" font="default" size="100%">Ahas, Rein</style></author><author><style face="normal" font="default" size="100%">Kurz-Besson, Cathy</style></author><author><style face="normal" font="default" size="100%">Lanta, Vojtěch</style></author><author><style face="normal" font="default" size="100%">Lebourgeois, François</style></author><author><style face="normal" font="default" size="100%">Miglietta, Franco</style></author><author><style face="normal" font="default" size="100%">Chuine, Isabelle</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Variation in cold hardiness and carbohydrate concentration from dormancy induction to bud burst among provenances of three European oak species</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">adult individuals</style></keyword><keyword><style  face="normal" font="default" size="100%">climate</style></keyword><keyword><style  face="normal" font="default" size="100%">distribution</style></keyword><keyword><style  face="normal" font="default" size="100%">frost dam- age</style></keyword><keyword><style  face="normal" font="default" size="100%">natural populations</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus pubescens</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus robur</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://treephys.oxfordjournals.org/content/27/6/817.abstract</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">27</style></volume><pages><style face="normal" font="default" size="100%">817 - 825</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Although cold hardiness is known to be a major determinant of tree species distribution, its dynamics and the factors that regulate it remain poorly understood. Variation in cold hardiness and carbohydrate concentration, from dormancy induction until bud burst, were investigated in populations of two deciduous (Quercus robur L. and Quercus pubescens Willd.) and one evergreen (Quercus ilex L.) European oak. Mean cold hardiness values in January were –56, –45 and –27 °C for Q. robur, Q. pubescens and Q. ilex, respectively. Soluble carbohydrate concentrations were closely related to instantaneous cold hardiness, estimated by the electrolyte leakage method, whereas total carbohydrate concentration was related to maximum cold hardiness. Both cold hardiness and carbohydrate concentration showed a close linear relationship with temperatures at the location of the sampled population. Our results show that temporal variation in both the inter- and intraspecific cold hardiness in European oaks can be related to variations in the concentrations of soluble carbohydrates and that these relationships appear to be driven by temperature.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><notes><style face="normal" font="default" size="100%">10.1093/treephys/27.6.81710.1093/treephys/27.6.817</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Morin, Xavier</style></author><author><style face="normal" font="default" size="100%">Améglio, Thierry</style></author><author><style face="normal" font="default" size="100%">Ahas, Rein</style></author><author><style face="normal" font="default" size="100%">Kurz-Besson, Cathy</style></author><author><style face="normal" font="default" size="100%">Lanta, Vojtěch</style></author><author><style face="normal" font="default" size="100%">Lebourgeois, François</style></author><author><style face="normal" font="default" size="100%">Miglietta, Franco</style></author><author><style face="normal" font="default" size="100%">Chuine, Isabelle</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Variation in cold hardiness and carbohydrate concentration from dormancy induction to bud burst among provenances of three European oak species</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">adult individuals</style></keyword><keyword><style  face="normal" font="default" size="100%">climate</style></keyword><keyword><style  face="normal" font="default" size="100%">distribution</style></keyword><keyword><style  face="normal" font="default" size="100%">frost dam- age</style></keyword><keyword><style  face="normal" font="default" size="100%">natural populations</style></keyword><keyword><style  face="normal" font="default" size="100%">Phenology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus pubescens</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus robur</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><volume><style face="normal" font="default" size="100%">27</style></volume><pages><style face="normal" font="default" size="100%">817-825</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Although cold hardiness is known to be a major determinant of tree species distribution, its dynamics and the factors that regulate it remain poorly understood. Variation in cold hardiness and carbohydrate concentration, from dormancy induction until bud burst, were investigated in populations of two deciduous (Quercus robur L. and Quercus pubescens Willd.) and one evergreen (Quercus ilex L.) European oak. Mean cold hardiness values in January were –56, –45 and –27 °C for Q. robur, Q. pubescens and Q. ilex, respectively. Soluble carbohydrate concentrations were closely related to instantaneous cold hardiness, estimated by the electrolyte leakage method, whereas total carbohydrate concentration was related to maximum cold hardiness. Both cold hardiness and carbohydrate concentration showed a close linear relationship with temperatures at the location of the sampled population. Our results show that temporal variation in both the inter- and intraspecific cold hardiness in European oaks can be related to variations in the concentrations of soluble carbohydrates and that these relationships appear to be driven by temperature.</style></abstract><notes><style face="normal" font="default" size="100%">10.1093/treephys/27.6.817</style></notes><research-notes><style face="normal" font="default" size="100%">10.1093/treephys/27.6.817</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sánchez, M. Concepción</style></author><author><style face="normal" font="default" size="100%">Martínez, M. Teresa</style></author><author><style face="normal" font="default" size="100%">Valladares, Silvia</style></author><author><style face="normal" font="default" size="100%">Ferro, Enrique</style></author><author><style face="normal" font="default" size="100%">Viéitez, Ana M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Maturation and germination of oak somatic embryos originated from leaf and stem explants: RAPD markers for genetic analysis of regenerants.</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of plant physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">DNA polymorphism</style></keyword><keyword><style  face="normal" font="default" size="100%">genetic stability</style></keyword><keyword><style  face="normal" font="default" size="100%">plant conversion</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus robur</style></keyword><keyword><style  face="normal" font="default" size="100%">Somatic embryogenesis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2003</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2003///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/12872492</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">160</style></volume><pages><style face="normal" font="default" size="100%">699 - 707</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Experiments were performed to determine the influence of maturation medium carbohydrate content on the rates of germination and plantlet conversion (root and shoot growth) of somatic embryos from four embryogenic lines derived from leaf or internode explants of Quercus robur L. seedlings. The conversion rate was favoured by high carbohydrate content as long as the maturation medium contained at least 2% sucrose, which was necessary for healthy embryo development. Given this, sorbitol and mannitol favoured the conversion rate more efficiently than sucrose, the highest rate, 32%, being achieved by medium with 6% sorbitol and 3% sucrose. Maturation treatment did not affect the root or shoot lengths of converted embryos. In supplementary experiments, 2 weeks of gibberellic acid treatment between maturation and germination treatments did not improve germination rates, but did reduce root length and the number of leaves per regenerated plantlet. In the four embryogenic lines tested, plant recovery rate was enhanced by inclusion of benzyladenine into the germination medium following culture of the embryos on maturation medium with 6% sorbitol and 2-3% sucrose. In embryogenic systems it is important to assess the uniformity of the regenerants. Random amplified polymorphic DNA (RAPD) analysis using 32 arbitrary oligonucleotide primers was performed to study variability in DNA sequences within and between four embryogenic lines. No intraclonal nor interclonal polymorphism was detected between embryogenic lines originating from different types of explant from the same seedling, but every one of the primers detected enough polymorphism among clones originating from different plants to allow these three origins to be distinguished. No differences in DNA sequences between regenerated plantlets and their somatic embryos of origin were detected, but a nodular callus line that had lost its embryogenic capacity was found to be mutant with respect to three other clones originating from the same plantlet. This study shows that high carbohydrate levels in the maturation medium significantly increase plant conversion of oak somatic embryos, which exhibit no variation in DNA sequences when proliferated by secondary embryogenesis.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;accession-num: 12872492</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sánchez, M Concepción</style></author><author><style face="normal" font="default" size="100%">Martínez, M Teresa</style></author><author><style face="normal" font="default" size="100%">Valladares, Silvia</style></author><author><style face="normal" font="default" size="100%">Ferro, Enrique</style></author><author><style face="normal" font="default" size="100%">Viéitez, Ana M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Maturation and germination of oak somatic embryos originated from leaf and stem explants: RAPD markers for genetic analysis of regenerants.</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of plant physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">DNA polymorphism</style></keyword><keyword><style  face="normal" font="default" size="100%">genetic stability</style></keyword><keyword><style  face="normal" font="default" size="100%">plant conversion</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus robur</style></keyword><keyword><style  face="normal" font="default" size="100%">Somatic embryogenesis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2003</style></year></dates><volume><style face="normal" font="default" size="100%">160</style></volume><pages><style face="normal" font="default" size="100%">699-707</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Experiments were performed to determine the influence of maturation medium carbohydrate content on the rates of germination and plantlet conversion (root and shoot growth) of somatic embryos from four embryogenic lines derived from leaf or internode explants of Quercus robur L. seedlings. The conversion rate was favoured by high carbohydrate content as long as the maturation medium contained at least 2% sucrose, which was necessary for healthy embryo development. Given this, sorbitol and mannitol favoured the conversion rate more efficiently than sucrose, the highest rate, 32%, being achieved by medium with 6% sorbitol and 3% sucrose. Maturation treatment did not affect the root or shoot lengths of converted embryos. In supplementary experiments, 2 weeks of gibberellic acid treatment between maturation and germination treatments did not improve germination rates, but did reduce root length and the number of leaves per regenerated plantlet. In the four embryogenic lines tested, plant recovery rate was enhanced by inclusion of benzyladenine into the germination medium following culture of the embryos on maturation medium with 6% sorbitol and 2-3% sucrose. In embryogenic systems it is important to assess the uniformity of the regenerants. Random amplified polymorphic DNA (RAPD) analysis using 32 arbitrary oligonucleotide primers was performed to study variability in DNA sequences within and between four embryogenic lines. No intraclonal nor interclonal polymorphism was detected between embryogenic lines originating from different types of explant from the same seedling, but every one of the primers detected enough polymorphism among clones originating from different plants to allow these three origins to be distinguished. No differences in DNA sequences between regenerated plantlets and their somatic embryos of origin were detected, but a nodular callus line that had lost its embryogenic capacity was found to be mutant with respect to three other clones originating from the same plantlet. This study shows that high carbohydrate levels in the maturation medium significantly increase plant conversion of oak somatic embryos, which exhibit no variation in DNA sequences when proliferated by secondary embryogenesis.</style></abstract><accession-num><style face="normal" font="default" size="100%">12872492</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Klap, J M</style></author><author><style face="normal" font="default" size="100%">Voshaar, J H Oude</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of environmental stress on forest crown condition in Europe. Part IV: statistical analysis of relationships</style></title><secondary-title><style face="normal" font="default" size="100%">Water, Air, &amp; Soil …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acid deposition</style></keyword><keyword><style  face="normal" font="default" size="100%">air pollution</style></keyword><keyword><style  face="normal" font="default" size="100%">correlative study</style></keyword><keyword><style  face="normal" font="default" size="100%">critical load</style></keyword><keyword><style  face="normal" font="default" size="100%">defoliation</style></keyword><keyword><style  face="normal" font="default" size="100%">Fagus sylvatica</style></keyword><keyword><style  face="normal" font="default" size="100%">forest vitality</style></keyword><keyword><style  face="normal" font="default" size="100%">meteorological stress</style></keyword><keyword><style  face="normal" font="default" size="100%">picea abies</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus sylvestris</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus petraea</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus robur</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><volume><style face="normal" font="default" size="100%">119</style></volume><pages><style face="normal" font="default" size="100%">387-420</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Site-speciﬁc estimates for various environmental stress factors were related with measured crown condition data at a systematic 16 16 km2 grid over Europe, according to previously stated hypotheses, using a multiple regression approach, including interactions, and lagged effects of stress factors. Methodological differences among countries accounted for &gt;30% of the variation in defoliation. Nevertheless, crown condition was found to vary naturally with tree age, altitude, drought stress and, most likely, also pathogenic fungi and insects. Signiﬁcant impacts of air pollution (speciﬁcally ozone but also NOx , SOx and acid deposition) were found at regional levels in parts of central Europe, particularly for deciduous species. Impacts seemed less signiﬁcant for conifers, especially for spruce, but this might be affected by confounding effects or strong correlations between (a harsh) climate and (low) atmospheric deposition in the area where spruce predominates. National studies indicate that ozone and acid deposition can have a signiﬁcant effect on the defoliation of spruce as well. We conclude that while forest condition varies naturally, continued emissions will contribute further to forest decline in the long term.</style></abstract></record></records></xml>