Selection perspectives for genetic improvement of wood stiffness in hybrid larch (Larix x eurolepis Henry)

Abstract

Genetic variability of modulus of elasticity (MOE) was investigated in three genetic trials, including two progeny (16 years old) and one clonal (19 years old) trials of hybrid larch (Larix x eurolepis Henry). MOE was directly assessed on standing trees using the Rigidimeter, a bending device, and related to other traits including height, BH diameter and wood density. Mean MOE ranged from 5,183 to 9,228 MPa among families in the progeny trials and from 4,591 to 11,486 MPa in the clonal trial. Among traits studied, MOE was one of the most variable traits. It was strongly and positively related to wood density at both the individual and genotype mean levels. Interestingly too, wood stiffness did not seem, or only weakly, unfavourably linked to stem diameter at the phenotypical level, but it was negatively or not correlated to diameter at the genetic level. As well, MOE showed a high GxE stability over the two progeny trial sites. Narrow-sense heritabilities for MOE were moderate (around 0.36). In all three trials, they were lower than those for wood density or total height, and of the same level as for diameter. Improvement of wood stiffness of hybrid larch using the Rigidimeter seems possible and promising genetic gains are expected. Impacts of selection for growth traits on MOE are also discussed.

Genetics of wood quality attributes in Western Larch

“…MOE D mirrored V Dir and gave similar genetic and phenotypic correlations. Phenotypic correlations between MOE D and growth attributes (HT, VOL, and DBH) in this study were similar to those reported by Pâques et al (2010).…”

“…The Interestingly, there were no significant (p <0.05) negative phenotypic or genetic wood quality-growth trait correlations in this study. Pâques et al (2010) reported weak and nonsignificant phenotypic correlations between MOE and stem growth in hybrid larch wood (Larix × eurolepis Henry). Zobel and van Buijtenen (1989 ; Table 5) reported similar wood quality-growth trait relationships for Larix .…”

Genetic relationship between wood properties and growth traits in Larix kaempferi obtained from a diallel mating test

“…Nakada et al [14] reported no or weak positive clonal correlation between diameter and wood quality traits, and Koizumi et al [13] reported no clonal correlation between DBH and MOE in Larix kaempferi. On the other hand, negative genetic correlations between growth traits and wood quality traits (wood density and MOE) were reported in hybrid larch [16][17][18], and negative correlations between growth traits and wood quality traits have also been reported in several other species in Pseudotsuga menziesii [38][39][40], in Picea sitchenis [41], and in Pinus radiata [42]. Mishima et al [37] reported a very small but positive clonal correlation between DBH and SWV in C. japonica.…”

“…Fukatsu et al [15] reported a positive genetic correlation between wood density and basal area. In hybrid larch, a strong negative genetic correlation between wood density and radial growth rate, and a weak negative genetic correlation between MOE and DBH were reported in Larix gmelinii 9 L. kaempferi hybrids [16,17], and a strong negative genetic correlation between DBH and MOE was reported in Larix decidua 9 L. kaempferi hybrids [18]. To predict how the selection of a trait will affect correlated traits in the following generations of L. kaempferi, more research is necessary.…”

Non-Destructive Evaluation Techniques and What They Tell Us about Wood Property Variation

“…The Rigidimeter is particularly well-suited for ranking genotypes [96,98,[103][104][105]. Rigidimeter MOE values showed large phenotypic and genetic variability (in contrast to some other wood traits like density), moderate to high levels of heritability and low genetic by environment (GxE) interaction [106,107]. In a study in New Zealand (unpublished), trunk MOE measured with the Rigidimeter on standing radiata pine trees was found to be genetically variable and significantly correlated with acoustic velocity and stem knottiness index.…”