Phenotypic and Genotypic Correlations for Wood Properties of Hybrid Poplar Clones of Southern Quebec

Abstract

This study aims to understand the phenotypic and genotypic correlations among wood anatomical, physical, and mechanical properties of hybrid poplar clones. Samples were taken from seven clones grown on three sites in Southern Quebec, Canada. Five trees per clone were randomly sampled from each site to measure anatomical (fiber length, fiber proportion, vessel proportion, fiber wall thickness, tension wood), physical (basic density, volumetric, longitudinal, tangential, and radial shrinkage), and mechanical wood properties (flexural modulus of elasticity (MOE), modulus of rupture (MOR), ultimate crushing strength parallel to the grain). The observed phenotypic and genotypic correlations between these wood properties were moderate to strong, except for fiber length and vessel proportion. Genotypic correlations for all wood properties were higher than for corresponding phenotypic correlations. Furthermore, fiber length showed weak correlations, whereas, vessel proportion showed strongly negative correlations with all other properties. Strong correlations were also found among fiber proportion, fiber wall thickness, basic density, and mechanical properties. Furthermore, results from this study show close genotypic and phenotypic correlations between fiber proportion, fiber wall thickness, and wood density, which consequently affect the mechanical performance of wood products. These findings indicate that there is a substantial opportunity to improve wood quality by selecting several wood properties for different end uses.

Variation in Wood Properties of Hybrid Poplar Lumber by Radial and Vertical Position in Stem: A Case Study from Boardman, Oregon

“…shrinkage by Koubaa et al (1998b) and Peters et al (2002) but nearly two percentage points higher than Huda et al (2018). The tangential shrinkage found in this study was closer to the values reported for Populus tremuloides than for hybrids (Jessome 1977).…”

“…The radial and vertical variation in SG are possibly the result of differences in the percentage and size of vessels and fibers in response to crown development as described in P. deltoides by Isebrands (1972); although tension wood and other fiber anatomical properties may also play a part (Bendtsen and Senft 1986;Beaudoin et al 1992;Badia et al 2006;Huda et al 2012). The significant and moderately strong positive correlations we observed between SG and MOR, hardness and screw withdrawal indicate that SG may be a reasonable proxy clonal selection criterion for multiple wood quality traits (Huda et al 2018). SG has previously been shown to be under strong genetic control (Beaudoin et al 1992;Peszlen 1998).…”

“…Koubaa et al (1998b) found an average tangential shrinkage of 9.5% for ten P. 3 euramericana clones and Peters et al (2002) reported tangential shrinkage that ranged from 6.64% to 9.91% for hybrid poplar clones, whereas the clonal average tangential swelling in this study was between 5.41% and 6.49%. Huda et al (2018) report a similarly low range for tangential dimensional stability with 3.95-6.12% across seven clones and three sites. The range of radial swelling in this study was almost identical to the range reported for radial Figure 2.…”

“…Although each clone had a different pattern, in general, tangential shrinkage increased from pith to middiameter then decreased outward. A suite of wood properties have found to be under moderate to high genetic control with little evidence for site by clone interactions in most properties relevant to wood products (Huda et al 2014(Huda et al , 2018.…”

Phenotypic Correlations among Growth and Selected Wood Properties in White Spruce (Picea glauca (Moench) Voss) †

“…Therefore, although the sampled trees represent a wide range of tree sizes, and the results are indicative of the relationships one could find in such material, care must be taken when generalizing the results to white spruce plantations or natural forest. In addition, phenotypic and genetic correlations may differ [66], so caution is advised when comparing the reported results with those from genetically improved trees.…”