Identification of putative candidate genes for juvenile wood density in Pinus radiata

During genetic sampling of white spruce in 1984, increment cores were taken from 80 populations in order to study wood density variation within species in natural Quebec forests. Results show that wood density differences exist between populations and that wood density is negatively correlated with the width of the growth rings; however, some trees and some populations exhibit both high wood density and rapid growth. A moderate positive link was found between juvenile and mature wood densities at both the individual and population levels. Therefore, breeding programs for the improvement of wood density could be based on selections made on juvenile wood.

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Genetic correlations among juvenile wood quality and growth traits and implications for selection strategy in Pinus radiata D. Don

Annals of Forest Science ◽

10.1051/forest/2009044 ◽

2009 ◽

Vol 66 (6) ◽

pp. 606-606 ◽

Cited By ~ 27

Author(s):

Washington J. Gapare ◽

Brian S. Baltunis ◽

Miloš Ivković ◽

Harry X. Wu

Keyword(s):

Pinus Radiata ◽

Growth Traits ◽

Juvenile Wood ◽

Wood Quality ◽

Genetic Correlations ◽

Selection Strategy

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Wood Density and Above-Ground Growth in High and Low Wood Density Clones of Pinus radiata D. Don

Functional Plant Biology ◽

10.1071/pp9900615 ◽

1990 ◽

Vol 17 (6) ◽

pp. 615 ◽

Cited By ~ 3

Author(s):

DW Sheriff ◽

DA Rook

Keyword(s):

Wood Density ◽

Pinus Radiata ◽

Light Treatment ◽

High Light ◽

The Other ◽

Stem Volume ◽

Carbon Gain ◽

Simple Relationship ◽

Ground Biomass ◽

High Light Treatment

In Pinus radiata a negative relationship has usually been found between stem volume and wood density. Clones previously found to produce wood of high or low density were used to investigate interrelationships between above-ground partitioning coefficients, carbon gain, and wood density. Cuttings had been propagated c. 5 years earlier, and were 5 m high when the experiment started. Potential carbon gain of the tree was manipulated by using two light environments; one with a light level c. 1.5 times the other. Measurements were of changes in stem, branch, and needle biomass during the 305-day experiment, of rates of photosynthesis, and of wood density by β-ray densitometry and microscopy; densities determined by the two techniques were the same. For all but two trees, wood densities of a stem and its branches were the same; for the other two, stem density was 13% less than that of their branches. Trees in the high light treatment accumulated more above-ground biomass, but there was no simple relationship between wood density and either above-ground growth or photosynthesis. With one exception, partitioning of photosynthate to stem was constant. In most cases, proportionately less photosynthate (30-80%) was allocated to below-ground biomass in the low light treatment than in the high light treatment (60-80%).

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Effects of live crown on vertical patterns of wood density and growth in Douglas-fir

Canadian Journal of Forest Research ◽

10.1139/x01-218 ◽

2002 ◽

Vol 32 (3) ◽

pp. 439-447 ◽

Cited By ~ 34

Author(s):

Barbara L Gartner ◽

Eric M North ◽

G R Johnson ◽

Ryan Singleton

Keyword(s):

Wood Density ◽

Juvenile Wood ◽

Growth Ring ◽

Ring Width ◽

Douglas Fir ◽

Mature Wood ◽

Node Number ◽

Growth Ring Width ◽

Residual Variation ◽

Wide Range

It would be valuable economically to know what are the biological triggers for formation of mature wood (currently of high value) and (or) what maintains production of juvenile wood (currently of low value), to develop silvicultural regimes that control the relative production of the two types of wood. Foresters commonly assume the bole of softwoods produces juvenile wood within the crown and mature wood below. We tested that assumption by comparing growth ring areas and widths and wood density components of the outer three growth rings in disks sampled from different vertical positions of 34-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. The 18 trees were sampled from one site and had a wide range of heights to live crown. Most of the variance (6393%) in wood characteristics (growth ring area: total, earlywood, latewood; growth ring width: total, earlywood, latewood; latewood proportion: by area, width; and ring density: total, earlywood, latewood) was due to within-tree differences (related to age of the disk). Stepwise regression analysis gave us equations to estimate wood characteristics, after which we analyzed the residuals with a linear model that included whether a disk was within or below the crown (defined as the lowest node on the stem with less than three live branches). After adjusting for tree and disk position, only 210% of the residual variation was associated with whether the disk was in or out of the live crown. There were no statistically significant differences at p = 0.05 between a given disk (by node number) in versus out of the crown for any of the factors studied. Moreover, the wood density characteristics were not statistically significant at p = 0.30. This research suggests that there was no effect of the crown position on the transition from juvenile to mature wood as judged by wood density. Therefore, we found no evidence to support the concept that tree spacing and live-branch pruning have a significant effect on the cambial age of transition from juvenile to mature wood in Douglas-fir trees of this age.

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Implications of selection history on genetic architecture of growth, form, and wood-quality traits in Pinus radiata

Canadian Journal of Forest Research ◽

10.1139/x08-086 ◽

2008 ◽

Vol 38 (9) ◽

pp. 2372-2381 ◽

Cited By ~ 10

Author(s):

S. Kumar ◽

R. D. Burdon ◽

G. T. Stovold ◽

L. D. Gea

Keyword(s):

Wood Density ◽

Pinus Radiata ◽

Wood Quality ◽

Genetic Correlations ◽

Wood Properties ◽

Radiata Pine ◽

Single Pair ◽

Narrow Sense Heritability ◽

Tree Form ◽

Selection History

Clonal trials of Pinus radiata D. Don (radiata pine), representing two populations (or breeds), one selected for growth and form (GF) and the other selected for high wood density as well as growth and form (HD), were replicated on two low-altitude New Zealand sites: Tarawera (pumice soil, 38°08′S) and Woodhill (coastal dune, 36°42′S). The GF material comprised 33 pair-crosses (19 parents) × 10 clones, and the HD material comprised 19 single-pair crosses (35 parents) × 10 clones, with six ramets per clone per site. Diameter (DBH), two tree-form variables, and needle retention (NRA) were assessed 8 years after planting, and wood density (DEN), acoustic velocity, and collapse were assessed 9 years after planting. The site differences were generally expressed more strongly in the GF population. Estimated genetic parameters were mostly similar for the two breeds, except that genotypic correlation between DBH and DEN was apparently zero in the HD population. Estimated broad-sense heritabilities (H2) were generally markedly higher than narrow-sense heritability estimates (h2), except with DEN. Estimated between-site type-B clonal genotypic correlations were generally high (>0.8) for wood properties. Overall, DBH showed adverse genetic correlations with wood properties. The Elite/Breed strategy appeared to be helpful in combating adverse genetic correlations.

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