Improvement of Pinus pinaster Ait elite trees selection by combining near infrared spectroscopy and genetic tools

Abstract

Abstract The first and the second generation of improved maritime pine (Pinus pinaster) have produced gains of up to 30% in stem volume, a reduction of final harvesting age by 10 years and a considerable improvement of stem straightness. The third generation will include wood quality traits for different end-uses, including pulp and fibre properties. To facilitate this goal, near infrared spectroscopy (NIRS) was used to estimate chemical composition with regard to lignin, cellulose, hemicelluloses, and extractive content, and lignin quality with regard to 4-hydroxy-phenylpropane/guaiacylpropane ratio. A total of 960 samples were investigated which were collected from a large number of trees (belonging to 80 families obtained by crossing 18 mothers and 20 fathers; there are 12 trees per family). Good calibration data was obtained between NIRS and wet chemistry methods (R2 values higher than 0.9 and good precision of prediction). To complete the NIRS work, kraft cookings in small scale, fibre morphology and microdensitometry investigations were also conducted. Genetic calculations indicated that for a 1% rate of selection on mothers and fathers, genetically induced changes are possible with lignin content (−3.8%), cellulose content (+1.3%), pulp yield (+1.8%), fibre length in pulps (+0.17 mm) and wood density (+50 kg m−3).