Genetic Improvement of White Spruce Mechanical Wood Traits—Early Screening by Means of Acoustic Velocity

Patrick Lenz,Jean Beaulieu,David Auty,John Mackay,Alexis Achim

doi:10.3390/f4030575

Patrick Lenz, Jean Beaulieu + Show 3 more

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https://doi.org/10.3390/f4030575

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Abstract

There is a growing interest to use acoustic sensors for selection in tree breeding to ensure high wood quality of future plantations. In this study, we assessed acoustic velocity as a selection trait for the improvement of mechanical wood properties in two 15- and 32-year-old white spruce (Picea glauca [Moench.] Voss) genetic tests. Individual heritability of acoustic velocity was moderate and of the same magnitude as heritability of wood density. Considerable genetic gain could be expected for acoustic velocity and a measure combining velocity and wood density. The relationship between acoustic velocity and cellulose microfibril angle (MFA) was strong on the genetic level and selection based on velocity could effectively improve MFA, which is one of the most important determinants of wood mechanical properties. Although low, the positive relationship between acoustic velocity and tree height presents an interesting opportunity for the improvement of both tree growth and wood quality. On the phenotypic level, MFA was more strongly correlated to acoustic velocity in mature trees than in young trees. The addition of easily obtainable traits such as diameter at breast height (DBH), height-to-diameter ratio as well as wood density to velocity determinations could improve models of MFA at the young and the mature age. We conclude that juvenile acoustic velocity is an appropriate trait to select for wood quality in a tree breeding context.

Highlights

White spruce (Picea glauca [Moench] Voss) spans the North American continent fromNewfoundland to Alaska and is one of the most important boreal conifer species for the Canadian forest industry
Tree breeding programs have been established for white spruce since the 1960s in different parts of Canada and the United States, but these have mainly focused on the improvement of growth and adaptive traits, even though faster growth is generally negatively correlated with important wood quality traits such as density and mechanical properties [2,3]
The coefficients of variation (CV) were generally higher in young trees for all traits expect for earlywood density and microfibril angle (MFA)

Summary

Introduction

White spruce (Picea glauca [Moench] Voss) spans the North American continent fromNewfoundland to Alaska and is one of the most important boreal conifer species for the Canadian forest industry. White spruce wood is highly valued for pulp and especially for lumber due to its good machining and structural properties [1]. In common with other boreal species, white spruce is very slow growing compared to more temperate species such as radiata pine Tree breeding programs have been established for white spruce since the 1960s in different parts of Canada and the United States, but these have mainly focused on the improvement of growth and adaptive traits, even though faster growth is generally negatively correlated with important wood quality traits such as density and mechanical properties [2,3]. There is a need to include wood traits in tree selection programs to ensure future wood supplies have the appropriate mechanical properties for structural applications and other end uses

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