Rapid assessment of wood traits for large-scale breeding selection in Picea mariana [Mill.] B.S.P

Abstract

Key message: Pilodyn and acoustic velocity measurements on standing trees, used for predicting density and stiffness, can be good genetic selection tools for black spruce. Genetic parameters and selection efficiency were conserved in two breeding zones with contrasted bioclimatic conditions. Context: Given the recent progress made in the black spruce genetic improvement program, the integration of juvenile wood mechanical properties as selection criteria is increasingly relevant. Aims: This study aims to estimate the genetic parameters of in situ wood density and modulus of elasticity (MoE) measurements and to verify the efficiency of various measuring methods used for large-scale selection of black spruce based on wood quality. Methods: Height, diameter, wood density, and some indirect measures of density (penetration and drilling resistance) and MoE (acoustical velocity and Pilodyn) were estimated on 2400 24-year-old trees of 120 open-pollinated families in progeny trials located in the continuous boreal or mixed forest subzones. Results: Heritability of growth, density, and indirect density measurements varied from low to moderate and was moderate for acoustical velocity in both vegetation subzones. Expected genetic gains for wood properties based on in situ methods were higher for MoE proxy estimation combining Pilodyn and acoustic velocity. Conclusion: Acoustic velocity is a good predictor of MoE. It is virtually unaffected by the environment and can be used on a large scale in the same manner as the Pilodyn for density. Using a proxy estimation that combines both methods helps optimize genetic gain for MoE.