scholarly journals Genetic correlations between pulpwood and solid-wood selection and objective traits in Eucalyptus globulus

2010 ◽  
Vol 67 (5) ◽  
pp. 511-511 ◽  
Author(s):  
Matthew G. Hamilton ◽  
Brad M. Potts ◽  
Bruce L. Greaves ◽  
Greg W. Dutkowski
New Forests ◽  
2019 ◽  
Vol 51 (1) ◽  
pp. 137-158 ◽  
Author(s):  
Henry Nickolas ◽  
Dean Williams ◽  
Geoff Downes ◽  
Paul Tilyard ◽  
Peter A. Harrison ◽  
...  

2011 ◽  
Vol 41 (6) ◽  
pp. 1333-1343 ◽  
Author(s):  
A.N. Callister ◽  
N. England ◽  
S. Collins

Eucalyptus globulus Labill. is increasingly considered for supply of solid-wood products such as sawlogs, yet genetic studies of solid-wood traits have been lacking. We estimated genetic parameters of growth and form traits that affect log value in full-sib families from two advanced-generation breeding populations on eight sites in Western Australia. Mean single-site heritability was 0.11 ± 0.01 for diameter at breast height (DBH), 0.28 ± 0.05 for stem straightness, 0.09 ± 0.02 for branch thickness, and 0.05 ± 0.02 for forking incidence. Dominance effects were significant (p < 0.05) at four sites for DBH and branch thickness and at three sites (one population) for straightness. Mean intersite additive genetic correlations were 0.76 ± 0.06 for DBH (n = 7), 0.75 ± 0.11 for stem straightness (n = 7), and 0.58 ± 0.07 for branch thickness (n = 4). Mean intersite dominance genetic correlations were 0.90 ± 0.04 for DBH (n = 7), 0.26 ± 0.27 (n = 4) for straightness, and 0.68 ± 0.11 for branch thickness (n = 3). Additive genetic correlations between DBH and straightness ranged from –0.71 ± 0.23 to 0.33 ± 0.19 with an average of –0.18 ± 0.12 (n = 8). Genetic correlations between DBH and branch thickness were mostly weak although straightness was generally associated with thinner branches (mean additive correlation 0.44 ± 0.15, n = 6). We conclude that prospects appear favourable for improving the solid-wood value of E. globulus by selection and breeding.


2010 ◽  
Vol 40 (5) ◽  
pp. 917-927 ◽  
Author(s):  
Desmond J. Stackpole ◽  
René E. Vaillancourt ◽  
Geoffrey M. Downes ◽  
Christopher E. Harwood ◽  
Brad M. Potts

Pulp yield is an important breeding objective for Eucalyptus globulus Labill., but evaluation of its genetic control and genetic correlations with other traits has been limited by its high assessment cost. We used near infrared spectroscopy to study genetic variation in pulp yield and other traits in a 16-year-old E. globulus trial. Pulp yield was predicted for 2165 trees from 467 open-pollinated families from 17 geographic subraces. Significant differences between subraces and between families within subraces were detected for all traits. The high pulp yield of southern Tasmanian subraces suggested that their economic worth was previously underestimated. The narrow-sense heritability of pulp yield was medium (0.40). The significant positive genetic correlation between pulp yield and diameter (0.52) was at odds with the generally neutral values reported. The average of the reported genetic correlations between pulp yield and basic density (0.50) was also at odds with our nonsignificant estimate. Pulp yield of the subraces increased with increasing latitude, producing a negative correlation with density (–0.58). The absence of genetic correlations within subraces between pulp yield and density suggests that the correlation may be an independent response of the two traits to the same or different selection gradients that vary with latitude.


2011 ◽  
Vol 59 (2) ◽  
pp. 170 ◽  
Author(s):  
M. G. Hamilton ◽  
P. A. Tilyard ◽  
D. R. Williams ◽  
R. E. Vaillancourt ◽  
T. J. Wardlaw ◽  
...  

Eucalyptus globulus is one of the best known examples of a heteroblastic plant. It exhibits a dramatic phase change from distinctive juvenile to adult leaves, but the timing of this transition varies markedly. We examined the genetic variation in the timing of heteroblastic transition using five large open-pollinated progeny trials established in north-western Tasmania. We used univariate and multi-variate mixed models to analyse data on the presence/absence of adult or intermediate foliage at age 2 years from a total of 14 860 trees across five trials, as well as height to heteroblastic phase change from one trial. Up to 566 families and 15 geographic subraces of E. globulus were represented in the trials. The timing of the heteroblastic transition was genetically variable and under strong genetic control at the subrace and within-subrace level, with single-trial narrow-sense heritability estimates for the binary trait averaging 0.50 (range 0.44–0.65). The degree of quantitative trait differentiation in the timing of heteroblastic transition among subraces, as measured by QST, exceeded the published level of neutral molecular marker (FST) differentiation in all cases, arguing that diversifying selection has contributed to shaping broad-scale patterns of genetic differentiation. Most inter-trial genetic correlations were close to one at the subrace and additive genetic levels, indicating that the genetic variation in this important developmental change is expressed in a stable manner and that genotype-by-environment interaction is minimal across the environments studied.


2002 ◽  
Vol 32 (1) ◽  
pp. 170-176 ◽  
Author(s):  
C A Raymond ◽  
L R Schimleck

Determining kraft pulp yield in the traditional way is slow and expensive, limiting the numbers of samples that may be processed. An alternative is to use a secondary standard, such as cellulose content of the wood, which is strongly correlated with kraft pulp yield. The feasibility and efficiency of predicting cellulose content using near infrared reflectance (NIR) analysis was examined for Eucalyptus globulus Labill. Calibrations for NIR prediction of cellulose content indicated that NIR analysis could be used as a reliable predictor. Standard errors of calibration were 1% or lower, and there was excellent agreement between laboratory and predicted cellulose values. Cellulose content was under moderate genetic control (h2 ranging from 0.32 to 0.57), and genetic correlations with tree diameter and basic density were variable (ranging from –0.11 to –0.51 and –0.33 to 0.67, respectively). The advantages, disadvantages, and potential applications of NIR analysis for predicting cellulose content are examined.


2007 ◽  
Vol 13 (1) ◽  
pp. 43-57
Author(s):  
T.G. Baker ◽  
P.W. Volker

La mayoría de las plantaciones de Eucalyptus han sido establecidas en la región templada de Australia (Australia Occidental, Australia Meridional, Victoria y Tasmania). Eucalyptus globulus es la principal especie en el área, con casi todas las plantaciones bajo el sistema de rotación corta para la producción de pulpa. En Tasmania y en Victoria, tal como en Chile, E. nitens ha sido utilizado como un sustituto de E. globulus, particularmente donde las bajas temperaturas son una limitante para esta última especie. La creciente reserva de bosques naturales, que han sido la fuente del tradicional recurso de la madera aserrada, ha despertado el interés en los productos de madera sólida de estas nuevas plantaciones de Eucalyptus. Hay resistencia a la utilización de la madera solida de Eucalyptus proveniente de plantaciones, principalmente de las industrias procesadoras debido a las dudas sobre la calidad de la madera y la idoneidad de las trozas para el procesamiento. Se requerirán muchas investigaciones para despejar estos temores. Este artículo describe algunos resultados de las investigaciones sobre las propiedades madereras y silvícolas de las plantaciones de Eucalyptus en el sur de Australia, además de las actuales prioridades y actividades de investigación.


2015 ◽  
Vol 45 (6) ◽  
pp. 615-624 ◽  
Author(s):  
Matthew G. Hamilton ◽  
Mauricio Acuna ◽  
John C. Wiedemann ◽  
Rick Mitchell ◽  
David J. Pilbeam ◽  
...  

The cost of harvesting short-rotation plantation eucalypts can be in excess of AU$2500·ha−1. Despite this high cost, the extent to which harvesting productivity is affected by tree genetics is not well understood. We address this issue in a study of two 10-year-old genetic field trials of Eucalyptus globulus Labill. in Australia. Standing-tree traits analysed were survival, diameter at breast height, basal area, and stem straightness and forking. Harvest traits analysed were volume, time, and productivity. Genetic group and within-group genetic variation (additive and dominance), stand-level family variation, phenotypic and genetic correlations, and the effects of inbreeding were estimated for these traits. The different scenarios studied showed that plantation harvest productivity was affected by tree genetics to some degree but was mainly affected through positive covariation with stem diameter. Harvest productivity is thus unlikely to have been adversely affected by past selection. Although no significant additive or dominance genetic variation in stem forking or straightness was detected, weak phenotypic correlations were consistent with harvest productivity being higher in straighter trees with no forking. High inbreeding depression was evident for growth and survival; however, in open-pollinated progeny, this resulted in only a slight reduction in harvest productivity (5.5%) compared with out-crossed progeny.


2009 ◽  
Vol 58 (1-6) ◽  
pp. 252-261 ◽  
Author(s):  
Matthew G. Hamilton ◽  
C. E. Harwood ◽  
B. M. Potts

Abstract Genetic variation in wood-sample gross shrinkage and basic density was examined in a Eucalyptus globulus base population trial growing in Tasmania, Australia. Gross shrinkage, which includes all components of shrinkage including collapse, was assessed in four ways (calliper- and visually-assessed tangential shrinkage, volumetric shrinkage and radial shrinkage) on samples dried at three temperatures (22°C, 60°C and 105°C). Significant differences between subraces were observed using all measures of gross shrinkage for two or more of the three drying treatments. Furthermore, significant additive genetic variation within subraces was observed in calliper- and visually-assessed gross shrinkage under two or more of the drying treatments, with narrowsense heritabilities greater than or equal to 0.35. There was no obvious trend in heritabilities or coefficients of additive genetic variation with drying temperature. Under the 105°C drying treatment, subrace correlations among calliper-, visually- and volume-assessed gross shrinkage were positive and very strong (≥ 0.97), while these measures were less strongly correlated with radial gross shrinkage at the subrace level (≤ 0.77). Withinsubrace genetic correlations among the first three measures were also strongly positive (≥ 0.95). These high genetic correlations suggest that different drying regimes and the calliper, visual and volume methods of assessment could be used interchangeably to select for reduced tangential gross shrinkage. Estimated subrace and genetic correlations between basic density and measures of gross shrinkage were universally negative (i.e. favourable), although not all were significantly different to zero.


2005 ◽  
Vol 54 (1-6) ◽  
pp. 160-166 ◽  
Author(s):  
L. A. Apiolaza ◽  
C. A. Raymond ◽  
B. J. Yeo

Abstract This study considered the degree of genetic variation for diameter (DBH), basic density (BD), predicted pulp yield (PPY), fibre length (FL), microfibril angle (MFA) and cellulose content (CC) amongst eight subraces of Eucalyptus globulus growing in a field trial in NW Tasmania. There were significant subrace effects for BD, FL and CC. This variation affected the relative profitability of the subraces for pulp production. On average, the most profitable subraces (on NPV/ha over the base population mean) were Strzelecki Ranges ($862.04), Western Otways ($657.80) and Strzelecki Foothills ($576.81). The genetic control (heritability) of variation in DBH, FL and MFA was moderate (0.15 < h2< 0.27), while control for BD, PPY and CC was high (h2> 0.40). Genetic correlations between growth and wood properties were not statistically significant, except for DBHMFA (-0.86). Most genetic correlations amongst wood properties were outside the parametric space (< -1 or >1), but there were significant correlations between BDMFA (-0.70) and PPY-CC (0.82). The empirical response to selection on an index based on a pulp wood objective (which included volume and basic density) resulted in a gain of 4.3% for DBH, 7.9% for BD and marginal changes for all other traits, with a net impact in profit of $1,270/ha. However, future profit calculations will need to consider the effect of FL, MFA and CC on the economics of wood processing to fully evaluate the economic impact of breeding.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 159
Author(s):  
Grace Jones ◽  
Mateusz Liziniewicz ◽  
Stergios Adamopoulos ◽  
Johan Lindeberg

This study investigated heritability of stem and wood traits to improve Swedish silver birch (Betula pendula Roth.) through breeding. Birch is 12% of Sweden’s forest area but mainly used for low value pulp or firewood. This paper applied non-destructive test (NDT) methods, and estimated traits’ heritability (h2), to help breed birch for high value solid wood products. Two trials of 22 families were assessed at age 19 for stem diameter (DBH), stem straightness, rough brown bark height (BH), grain angle (GA), Pilodyn penetration depth (Pilo) and acoustic velocity (AV). X-ray densitometry was performed on a subsample of radial cores taken at 1.3 m from the ground to get an average benchmark density. The h2 values were moderate for GA (0.20 and 0.21) and Pilo (0.53 and 0.48) at the two sites, but the h2 values for AV were low (0.05 and 0.30). There were moderate genotypic correlations between BH and DBH (0.51–0.54). There were low genotypic and phenotypic correlations between NDT measurements and other traits so including NDT in birch breeding efforts should not inadvertently reduce size, stem or wood quality. The high genetic correlations between sites suggest that GA, Pilo and AV values were determined more by genotype than by environment.


Sign in / Sign up

Export Citation Format

Share Document