Genetic parameters of growth, straightness and wood chemistry traits in Pinus pinaster

Abstract

Abstract& Introduction Tree breeding is giving an increasing attention to wood properties in order to better fit the requirements of the saw, board, pulp and paper industries. In particular, it has been reported that lignin and cellulose content display moderate to high heritabilities making them prime candidates for genetic improvement of wood chemistry. Moreover, these traits have been shown to be negatively correlated at both phenotypic and genetic levels. However, they have generally been evaluated against a narrow genetic background, and little is known about their correlations with mandatory selection criteria such as growth and straightness.& Materials and methods In this study, we first investigated the performance of near-infrared (NIR) spectroscopy combined with a non-destructive sampling method to assess chemical properties of wood in maritime pine. We afterwards estimated genetic parameters of growth, stem form and wood chemistry traits across a large genetic background in a progeny trial and clonally replicated progenies. & Results Our results showed that removal of extractives prior to NIR spectra acquisition is highly recommended for achieving high accuracy in NIRS-PLSR prediction for wood chemistry traits in maritime pine.We further observed moderate heritabilities (0.15-0.55) for the studied traits. Wood chemistry traits were genetically inter-correlated (e.g., negatively between lignin and cellulose), whereas correlations with growth were not significant, indicating that growth and chemical properties could be improved independently.

Modeling additive and non-additive effects in a hybrid population using genome-wide genotyping: prediction accuracy implications

“…In the case of height at 32 months, our results stressed the importance of non-additive effects and confirmed the findings of previous studies of Baltunis et al (2009) with radiata pine and Araujo et al (2012) with E. globulus dealing with growth traits. However, they differed from earlier forest tree studies using full-sib families with clonal replicates and analyzing growth traits, which revealed a very low or limited proportion of non-additive variance, for example, Lepoittevin et al (2011) with maritime pine. Our results could be explained by the inter-species hybrid nature of our material, which can exacerbate heterosis (Melchinger et al, 2007).…”

“…With the progeny models, we estimated null epistatic variances and a very high dominance variance. Null epistatic variance may result from a small contribution of this effect to the genetic variance of growth traits, as observed in other forest tree studies (Lepoittevin et al, 2011;Araujo et al, 2012) and/or because we implemented an overfitted model, which could lead to null variance estimates. Increasing the number of parents and reducing the imbalance in the mating design could be a way to better estimate non-null epistatic variances and reduce their s.e.…”

A review of recent application of near infrared spectroscopy to wood science and technology

“…The selection of relevant wavenumbers combined with the appropriate data pre-processing methods which produced satisfactory prediction models. In the case of Maritime pine, Lepoittevin et al [10] showed that removal of extractives prior to NIR spectra acquisition is highly recommended for achieving high accuracy in partial least squares regression (PLSR) prediction for wood chemistry traits. Schwanninger et al [11,12] built a predictive model for lignin content in Norway spruce wood.…”

Challenges in the use of Near Infrared Spectroscopy for improving wood quality: A review

“…According to their findings, 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 ). Lepoittevin et al (2011) also developed NIR calibrations for assessing chemical properties of wood in maritime pine and estimated genetic parameters of wood chemistry traits across a large genetic background in a progeny trial and clonally replicated progenies. Based on these predictions, they reported heritability estimates from 0.21 to 0.25 for lignin; from 0.17 to 0.18 for cellulose; and 0.17 to 0.55 to hemicelluloses.…”