-Wood is one of our most important natural resources and has been exploited for many hundreds of years as fuel, building material and a source of paper. Its composition is variable among and within species. The ability to monitor the intra-specific variability is a prerequisite to improve wood and end-products properties. This paper describes a study of the genetic control of a large set of wood properties, including growth, timber quality traits, wood chemical composition, kraft pulp production parameters and pulp properties, in a 12 × 12 half diallel of maritime pine (Pinus pinaster Ait.). While relatively high (h ns 2 > 0.3) narrow-sense heritabilities were observed for density heterogeneity, lignin content, alpha-cellulose content and coarseness, no significant genetic effect was detected for hemi cellulose, water extractives, kraft pulp production parameters and pylodin. Slightly lower heritabilities (0.15 < h ns 2 < 0.3) were also obtained for wood density and fibre properties (length, width, curl, zero span). As a consequence and considering the phenotypic coefficient of variation obtained for these traits, improvement by selection of trees with outstanding wood quality is feasible. Nevertheless, it seems obvious that wood quality breeding can not be done without taking into account growth, and the only way to manage this constraint (negative correlation between growth and density) will be the constitution of elite "wood quality" populations in a already growth improved genetic population.wood quality / heritability / genetic correlation / tree breeding / Pinus pinaster Ait.Résumé -Déterminisme génétique des propriétés du bois impliquées dans la production papetière et la qualité du bois d'oeuvre chez le Pin maritime (Pinus pinaster Ait.). Le bois, une des ressources naturelles les plus importantes, est exploité depuis des centaines d'années comme combustible, matériau de construction et source de papier. Sa composition est très variable, non seulement entre espèces mais aussi au niveau intra spécifique. La compréhension de cette variabilité intra spécifique est un pré-requis de l'amélioration des propriétés des produits à base de bois. L'objectif de l'étude présentée ici est la compréhension du déterminisme génétique de plusieurs caractères impliqués dans la composition chimique et les propriétés du bois (caractéristiques physiques, paramètres de production industrielle et propriétés de la pâte) grâce à l'étude d'un demi diallèle 12 × 12. Bien que des héritabilités au sens strict relativement élevées (h ns 2 > 0,3) aient été obtenues pour l'hétérogénéité de la densité, les contenus en lignine et en alpha-cellulose et la masse linéique, aucun effet génétique significatif n'a été mis en évidence pour le contenu en hémi-cellulose, les extractibles, les paramètres de production de pâtes kraft, et la densité estimée grâce au pilodyn. Des héritabilités plus faibles (0,15 < h ns 2 < 0,3) ont quant à elles été obtenues pour la densité du bois et les propriétés des fibres (longueur, largeur, courbure, ri...
BackgroundCork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management.ResultsWe generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org.ConclusionsThis genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.
In the contemporary world, "race" narratives are so multifaceted that at times, different views of the concept appear mutually incompatible. In recent decades biologists, especially geneticists, have repeatedly stated that the notion of race does not apply to the human species. On the other hand, social scientists claim that race is highly significant in cultural, historical, and socioeconomic terms because it molds everyday social relations and because it is a powerful motivator for social and political movements based on race differences. In this paper we present the results of an interdisciplinary research project incorporating approaches from genetics and anthropology. Our objective is to explore the interface between information about biology/genetics and perceptions about color/ race in Rio de Janeiro, Brazil. We argue that the data and interpretation of our research resonate far beyond the local level, stimulating discussion about methodological, theoretical, and political issues of wider national and international relevance. Topics addressed include the complex terminology of color/race classification in Brazil, perceptions about ancestry in the context of ideologies of Brazilian national identity, and the relationship between genetic information about the Brazilian population and a sociopolitical agenda that turns on questions of race and racism.
Solid-phase microextraction (SPME)-liquid chromatography (LC) is used to analyze tricyclic antidepressant drugs desipramine, imipramine, nortriptyline, amitriptyline, and clomipramine (internal standard) in plasma samples. Extraction conditions are optimized using a 2(3) factorial design plus a central point to evaluate the influence of the time, temperature, and matrix pH. A Polydimethylsiloxane-divinylbenzene (60-mum film thickness) fiber is selected after the assessment of different types of coating. The chromatographic separation is realized using a C(18) column (150 x 4.6 mm, 5-microm particles), ammonium acetate buffer (0.05 mol/L, pH 5.50)-acetonitrile (55:45 v/v) with 0.1% of triethylamine as mobile phase and UV-vis detection at 214 nm. Among the factorial design conditions evaluated, the best results are obtained at a pH 11.0, temperature of 30 degrees C, and extraction time of 45 min. The proposed method, using a lab-made SPME-LC interface, allowed the determination of tricyclic antidepressants in in plasma at therapeutic concentration levels.
All rights reserved Blackwood (Acacia melanoxylon R. Br.) is native in eastern Australia over a wide range of latitude and longitude. 1 Considered a great decorative timber, it was introduced into many countries including South Africa, New Zealand, Vietnam, China and Chile. 1 In Portugal, blackwood was introduced at the beginning of the twentieth century in dry and poor sandy soils along the coast, mainly for dune protection. 2 The estimated planted area of blackwood in Portugal is about 30 thousand hectares in pure and mixed stands mainly with maritime pine. 2 Despite it being considered an invader species in Europe, 3 the timber value for solid wood products is normally twice as high as that of maritime pine, the main Portuguese species, produced in the same stands. Very little is known about the properties of this wood grown in Portugal, except for recent reports on pulp production 4,5 and heartwood variation. 6 Wood density is considered the most important property due to its relationship with many others including mechanical properties, calorific value and to its influence on yield, strength and general quality. 7 In many cases, density is the sole wood property assessed in breeding programmes, due to a large within species variation, a high degree of genetic control and easy assessment. Wood basic density, the ratio of
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