Evaluation of Wood Quality Traits in Salix viminalis Useful for Biofuels: Characterization and Method Development

Salix (willow) is a well-known coppice plant that has been used as source for bioenergy decades. With recent developments in changing from fossil-based to circular bioeconomy, greater interest orientated towards willow potential of biomass transport biofuels. This created increasing breeding strategies produce interesting genotypic and phenotypic traits different varieties. In the present study, 326 genetically distinct clones several commercial varieties S. viminalis were analyzed using complementary approaches including density, chemical, image, histochemical, morphometric analyses. A systematic approach was adopted whereby basal regions harvested stems separated all studies aid comparisons. Density analyses performed on clone individuals, results, 20 individual plants representing 19 selected more in-depth (chemical, image analysis, morphometric). The absolute dry density varied between ca. 300 660 kg/m3 with less variation seen (ca. 450–520 kg/m3). Selected chemical analysis showed largest glucose (47.3%–60.1%; i.e., cellulose) total sugar content, which ranged 61 77% only 16 22% lignin. Image entire stem sections presence tension wood variable amounts 7%–39%) characteristic G-fibers containing cellulose-rich non-lignified gelatinous layers. Several showing prominent also high content well low lignin levels. an optical fiber analyzer (OFA) analyzing 1000 s (minimum 100,000 particles) macerated fibers evaluated convenient tool determining samples. Statistical same thickness, OFA could separate normal by length but not width. Results emphasized considerable variability physical adopted, common aspect occurrence wood. Since G-layers represents increased readily available non-recalcitrant cellulose biofuels, programs should be factors its enhancement.