Microevolution of European temperate oaks in response to environmental changes

AbstractThis review reconstructs microevolutionary processes that allowed long-lived species as temperate oaks (Quercus petraea and Q. robur) to cope with climate change since the last glacial maximum, by assembling insights from complementary synchronic and allochronic approaches. Paleobotanical and genetic investigations show that oaks migrated at larger velocities than expected, thanks to long-distance rare events and most likely human interferences. Hybridization was a key mechanism accelerating migration and enhancing species succession. Common garden experiments and genome wide association studies demonstrated that diversifying selection across large environmental gradients contributed to rapid local adaptation. Finally the review explores how lessons taken from past evolutionary scenarios may help to predict future responses of oaks to ongoing climate change

Electronic structure and thermoelectric properties of CuRh(1-x)MgxO2

Electronic structure calculations using the augmented spherical wave method have been performed for CuRhO2. For this semiconductor crystallizing in the delafossite structure, it is found that the valence band maximum is mainly due to the 4d t2g orbitals of Rh^{3+}. The structural characterizations of CuRh(1-x)MgxO2 show a broad range of Mg^{2+} substitution for Rh^{3+} in this series, up to about 12%. Measurements of the resistivity and thermopower of the doped systems show a Fermi liquid-like behavior for temperatures up to about 1000K, resulting in a large weakly temperature dependent power factor. The thermopower is discussed both within the Boltzmann equation approach as based on the electronic structure calculations and the temperature independent correlation functions ratio approximation as based on the Kubo formalism.Comment: 9 pages, 12 figures, more information at http://www.physik.uni-augsburg.de/~eyert

Quantitative trait dissection analysis in Eucalytus using RAPD markers: 2. Linkage disequilibrium in a factorial design between E. urophylle and E. Grandis.

International audience.4 13 x 13 factorial design between E. rlr.opllj,llu and E. grmclis, comprising 87 full-sib families, was used to assess the relationships between RAPD marker frequency classes obtained from parental genotypes and the interspecific additive mean (IAM) of the hybrid progeny. For any markcr showing a significant association, the cumulative number of the " present band " allele in the parents was significantly correlated either positively or negatively, with the IAM of the traits studied: i.e. volume, stem taper and wood quality. We discuss the potential origin of such correlations in terms of linkage disequilibrium between QTL allele and marker allele. We also examine the possible use of such information, firstly in order to select the parents for further generations of breeding, and secondly in ordcr to choose thc hybrid families in which QTAs of specific value could be detected and uscd to identify the best trees to be vegetatively propagated for the production of clonal variety

Reducing Equational Theories for the Decision of Static Equivalence

International audienceStatic equivalence is a well established notion of indistinguishability of sequences of terms which is useful in the symbolic analysis of cryptographic protocols. Static equivalence modulo equational theories allows for a more accurate representation of cryptographic primitives by modelling properties of operators by equational axioms. We develop a method that allows us in some cases to simplify the task of deciding static equivalence in a multi-sorted setting, by removing a symbol from the term signature and reducing the problem to several simpler equational theories. We illustrate our technique at hand of bilinear pairings

Mg substitution in CuCrO2 delafossite compounds

A detailed investigation of the series CuCr(1-x)MgxO2 (x = 0.0 - 0.05) has been performed by making high-temperature resistivity and thermopower measurements, and by performing a theoretical analysis of the latter. Microstructure characterization has been carried out as well. Upon Mg2+ for Cr3+ substitution, a concomitant decrease in the electrical resistivity and thermopower values is found, up to x ~ 0.02 - 0.03, indicating a low solubility limit of Mg in the structure. This result is corroborated by scanning electron microscopy observations, showing the presence of MgCr2O4 spinels as soon as x = 0.005. The thermopower is discussed in the temperature-independent correlation functions ratio approximation as based on the Kubo formalism, and the dependence of the effective charge carrier density on the nominal Mg substitution rate is addressed. This leads to a solubility limit of 1.1% Mg in the delafossite, confirmed by energy dispersive X-ray spectroscopy analysis.Comment: 6 pages, 5 figure

Kocsánytalan tölgy populációk fiatalkori magassági növekedése szimulált klímaváltozás hatására, egy származási kísérletsorozatban

A tanulmány kiválasztott kocsánytalan tölgy populációk szimulált klímaváltozásra adott fenotípusos válaszreakcióját (reakciónormáját) mutatja be egy, a francia INRA által kezdeményezett nemzetközi származási kísérlet 10 éves magassági adatai alapján. A reakciónormákat a klímatolerancia becslésére alkalmaztuk, az eredeti termőhelynél melegebb és szárazabb helyszíneken. Az egy irányban változó klímaviszonyokra adott válasz-regressziókat lineárisnak találtuk. A maximális növekedési potenciált a populációk alkalmazkodott termőhelyüknél kedvezőbb feltételek mellett mutatták. A különböző klímákhoz adaptált populációk fenotípusos plaszticitása, vagyis klíma-érzékenysége szignifikánsan eltérő mértékűnek bizonyult. A Kárpát-medencei származások a többi európai populációhoz képest átlagos teljesítményt mutattak. A szárazsági határhoz közelebbi populációk jobb klíma-toleranciája a szaporítóanyag felhasználás szempontjából a kísérlet legfontosabb eredménye. Az eredmények a „támogatott áttelepítés/vándorlás” koncepcióját a kocsánytalan tölgy esetében megerősítik, és az alkalmazkodó erdőművelés országos stratégiája fejlesztéséhez felhasználhatók

Bioinformatic analysis of ESTs collected by Sanger and pyrosequencing methods for a keystone forest tree species: oak

<p>Abstract</p> <p>Background</p> <p>The Fagaceae family comprises about 1,000 woody species worldwide. About half belong to the <it>Quercus </it>family. These oaks are often a source of raw material for biomass wood and fiber. Pedunculate and sessile oaks, are among the most important deciduous forest tree species in Europe. Despite their ecological and economical importance, very few genomic resources have yet been generated for these species. Here, we describe the development of an EST catalogue that will support ecosystem genomics studies, where geneticists, ecophysiologists, molecular biologists and ecologists join their efforts for understanding, monitoring and predicting functional genetic diversity.</p> <p>Results</p> <p>We generated 145,827 sequence reads from 20 cDNA libraries using the Sanger method. Unexploitable chromatograms and quality checking lead us to eliminate 19,941 sequences. Finally a total of 125,925 ESTs were retained from 111,361 cDNA clones. Pyrosequencing was also conducted for 14 libraries, generating 1,948,579 reads, from which 370,566 sequences (19.0%) were eliminated, resulting in 1,578,192 sequences. Following clustering and assembly using TGICL pipeline, 1,704,117 EST sequences collapsed into 69,154 tentative contigs and 153,517 singletons, providing 222,671 non-redundant sequences (including alternative transcripts). We also assembled the sequences using MIRA and PartiGene software and compared the three unigene sets. Gene ontology annotation was then assigned to 29,303 unigene elements. Blast search against the SWISS-PROT database revealed putative homologs for 32,810 (14.7%) unigene elements, but more extensive search with Pfam, Refseq_protein, Refseq_RNA and eight gene indices revealed homology for 67.4% of them. The EST catalogue was examined for putative homologs of candidate genes involved in bud phenology, cuticle formation, phenylpropanoids biosynthesis and cell wall formation. Our results suggest a good coverage of genes involved in these traits. Comparative orthologous sequences (COS) with other plant gene models were identified and allow to unravel the oak paleo-history. Simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs) were searched, resulting in 52,834 SSRs and 36,411 SNPs. All of these are available through the Oak Contig Browser <url>http://genotoul-contigbrowser.toulouse.inra.fr:9092/Quercus_robur/index.html</url>.</p> <p>Conclusions</p> <p>This genomic resource provides a unique tool to discover genes of interest, study the oak transcriptome, and develop new markers to investigate functional diversity in natural populations.</p