In the last years, forestry scientists have adapted genomics and next-generation sequencing (NGS) technologies to the search for candidate genes related to the transcriptomics of secondary growth and wood formation in several tree species. Gymnosperms, in particular, the conifers, are ecologically and economically important, namely, for the production of wood and other forestry end products. Until very recently, no whole genome sequencing of a conifer genome was available. Due to the gradual improvement of the NGS technologies and inherent bioinformatics tools, two draft assemblies of the whole genomes sequence ofPicea abiesandPicea glaucaarose in the current year. These draft genome assemblies will bring new insights about the structure, content, and evolution of the conifer genomes. Furthermore, new directions in the forestry, breeding and research of conifers will be discussed in the following. The identification of genes associated with the xylem transcriptome and the knowledge of their regulatory mechanisms will provide less time-consuming breeding cycles and a high accuracy for the selection of traits related to wood production and quality.
31 August 2017 in iForest - Biogeosciences and Forestry
The reduction of resinous species in Portuguese forest areas has caused constraints to wood industry supplies. Portugal represents the extreme southwest of Scots pine (Pinus sylvestris) natural distribution and large gaps exist in the knowledge of its wood-quality characteristics. Understanding the relationship between these traits is important for recognizing which combination of wood properties is the most suitable for specific uses. To address these questions, we assessed wood-quality traits, namely, wood-density components (microdensitometric analysis), chemical composition (NIR spectrometry) and mechanical properties (bending tests) of wood samples collected at five representative forest sites in Portugal. Our results showed that Portuguese Pinus sylvestris has good radial growth and denser wood, higher extractive content and higher stiffness and strength than northern European provenances. The lignin content was within the range attributed to softwoods. Among the Portuguese stands, trees growing at lower-altitude sites exhibited denser wood and higher mechanical properties, while trees from high-elevations showed higher amounts of lignin. Ring density was more strongly correlated with earlywood than latewood density. A negative, non-significant correlation was found between ring density and width, supporting the assumption that the higher radial growth (ring width) does not negatively affect wood quality (density). In general, chemical properties had a weak relationship with physical and mechanical properties (MOE and MOR). Both mechanical traits were positively correlated with density and growth components, supporting the assumption that trees with high radial growth do not exhibit poorer mechanical performances.