Genetic variation of wood density components in young coastal Douglas-fir: implications for tree breeding

1991 ◽  
Vol 21 (12) ◽  
pp. 1801-1807 ◽  
Author(s):  
Jesus Vargas-Hernandez ◽  
W. T. Adams
Keyword(s):  
Genetic Control ◽  
Wood Density ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Density Variation ◽  
Douglas Fir ◽  
Control Individual ◽  
Individual Tree ◽  
Breast Height ◽  
Efficiency Of Selection

The genetic control of wood density components (earlywood density, latewood density, and latewood proportion) and their relationships with overall density in coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) were examined to assess the usefulness of this information in breeding for wood density. The genetic relationships of wood density with intraring density variation and bole volume growth were also investigated. Increment cores were taken at breast height from 15-year-old trees of 60 open-pollinated families. Averages across each core for overall wood density, its components, and intraring density variation were determined by using X-ray densitometry. Bole volume at age 15 for the same trees was derived from tree height and diameter at breast height measurements. Although wood density components varied significantly among families and were under moderate genetic control (individual-tree heritability (hi2) > 0.24), none had a higher heritability than overall density (hi2 = 0.59). Density components had strong genetic correlations with overall density (r ≥ 0.74) but were also strongly related among themselves (0.57 ≤ r ≤ 0.92). Thus, density components have limited value in improving the efficiency of selection for overall density. Overall density was positively correlated with intraring density variation (r = 0.72) and negatively correlated with bole volume (r = −0.52). Comparison of several selection indices incorporating wood density and one or more growth traits, however, showed that it is possible to obtain substantial gains in bole volume without loss in (or even with a modest increase in) wood density. By restricting the response in wood density, the change in intraring density variation can also be limited.

Genetic relationships between wood density components and cambial growth rhythm in young coastal Douglas-fir

1994 ◽  
Vol 24 (9) ◽  
pp. 1871-1876 ◽  
Author(s):  
Jesus Vargas-Hernandez ◽  
W.T. Adams
Keyword(s):  
Genetic Control ◽  
Wood Density ◽  
Genetic Relationships ◽  
Growth Period ◽  
Wood Formation ◽  
Douglas Fir ◽  
Increment Core ◽  
Growth Rhythm ◽  
Cambial Growth ◽  
Growth Initiation

To better understand the genetic control of wood formation in coastal Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco), and to assess the potential impact of selecting for increased wood density on adaptation of trees, genetic relationships of wood density, and its components, with cambial growth rhythm traits were examined in a 15-year-old progeny test. Timing of diameter growth during the 1987 growing season was available from an earlier study, and wood formation traits were estimated by X-ray densitometry of increment core samples. Wood formation traits were under weak genetic control [Formula: see text]. Lengths of earlywood and latewood formation were mostly determined by the timing of latewood transition. Overall core density was negatively correlated with the dates of cambial growth initiation (rA = −0.41) and latewood transition (rA = −0.62), and positively correlated with the date of cambial growth cessation (rA = 0.40). As a result of these relationships, higher wood density was associated with a longer duration of cambial growth (rA = 0.67) and a slower rate of wood formation (rA = −0.37). All density components showed similar relationships with cambial phenology and wood formation traits. Selection for increased wood density is expected to cause only a slight extension of the cambial growth period, but it would also cause an earlier transition to latewood formation, negatively affecting growth rate.

Genetic selection for cold hardiness in coastal Douglas-fir seedlings and saplings

2000 ◽  
Vol 30 (11) ◽  
pp. 1799-1807 ◽  
Author(s):  
Gregory A O'Neill ◽  
Sally N Aitken ◽  
W Thomas Adams
Keyword(s):  
Genetic Control ◽  
Cold Hardiness ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Douglas Fir ◽  
Direct Selection ◽  
Bud Burst ◽  
Individual Tree ◽  
Breeding Populations ◽  
Bud Set

Genetic control of cold hardiness in two-year-old seedlings was compared with that in 7-year-old saplings of 40 open-pollinated families in each of two breeding populations (Coast and Cascade) of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) from western Oregon. In addition, the efficacy of bud phenology traits as predictors of cold hardiness at the two stages was explored. Fall and spring cold hardiness were assessed using artificial freeze testing. Similar genetic control of cold hardiness in seedlings and saplings is suggested by strong type-B genetic correlations (rB) between the two ages for fall and spring cold injury traits (rB[Formula: see text] 0.78) and by similar trends in individual tree heritability estimates (hi2), e.g., hi2was greater in spring (h–i2= 0.73) than in fall (h–i2= 0.36) and greater in the Coast population (h–i2= 0.69) than in the Cascade population (h–i2= 0.40) at both ages. Strong responses to direct selection are expected for spring cold hardiness at both ages and for fall cold hardiness in seedlings, even under mild selection intensities. Similar heritabilities in seedlings and saplings, and strong genetic correlations between ages for cold-hardiness traits, ensure that selection at one age will produce similar gains at the other age. Type-A genetic correlations (rA) between fall and spring cold hardiness were near zero in the Cascade population (rA= 0.08 and -0.14 at ages 2 and 7, respectively) but were moderate and negative in the Coast population (rA= -0.54 and -0.36, respectively). Bud-burst timing appears to be a suitable surrogate to artificial freeze testing for assessing spring cold hardiness in both seedlings and saplings, as is bud set timing for assessing fall cold hardiness in seedlings, but bud set timing is a poor predictor of fall cold hardiness in saplings.

Heritability and phenotypic and genetic correlations of coastal Douglas-fir (Pseudotsuga menziesii) wood quality traits

2008 ◽  
Vol 38 (6) ◽  
pp. 1536-1546 ◽  
Author(s):  
Nicholas K. Ukrainetz ◽  
Kyu-Young Kang ◽  
Sally N. Aitken ◽  
Michael Stoehr ◽  
Shawn D. Mansfield
Keyword(s):  
Cell Wall ◽  
Genetic Control ◽  
Pseudotsuga Menziesii ◽  
Wood Quality ◽  
Genetic Correlations ◽  
Douglas Fir ◽  
Correlated Response ◽  
Sample Population ◽  
Quality Traits ◽  
Glucose Content

Genetic control and relationships among coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) growth and wood quality traits were assessed by estimating heritability and phenotypic and genetic correlations using 600 trees representing 15 full-sib families sampled from four progeny test sites. Heritability estimates ranged from 0.23 to 0.30 for growth traits, 0.19 for fibre coarseness, from 0.21 to 0.54 for wood density, from 0.16 to 0.97 for cell wall carbohydrates, and 0.79 and 0.91 for lignin content at two sites, Squamish River and Gold River, respectively. Glucose content, indicative of cell wall cellulose composition, and lignin were shown to be under strong genetic control, whereas fibre coarseness was shown to be under weak genetic control. Phenotypic correlations revealed that larger trees generally have longer fibres with higher fibre coarseness, lower density, lower carbohydrate content, a greater proportion of cell wall lignin, and higher microfibril angle. Genetic correlations and correlated response to selection suggest that breeding for height growth would result in a reduction in wood quality, whereas breeding for improved earlywood density in Douglas-fir would result in negligible reductions in volume and appears to be an ideal target for selecting for improved wood quality (density) while maintaining growth in the sample population.

scholarly journals Genetic control of stiffness of standing Douglas fir; from the standing stem to the standardised wood sample, relationships between modulus of elasticity and wood density parameters. Part II

1999 ◽  
Vol 56 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Philippe Rozenberg ◽  
Alain Franc ◽  
Cécile Mamdy ◽  
Jean Launay ◽  
Nicolas Schermann ◽  
...  
Keyword(s):  
Genetic Control ◽  
Wood Density ◽  
Modulus Of Elasticity ◽  
Wood Sample ◽  
Douglas Fir

Optimum selection age for wood density in loblolly pine

2002 ◽  
Vol 32 (8) ◽  
pp. 1393-1399 ◽  
Author(s):  
D P Gwaze ◽  
K J Harding ◽  
R C Purnell ◽  
F E Bridgwater
Keyword(s):  
Linear Relationship ◽  
Wood Density ◽  
Genetic Correlations ◽  
Core Density ◽  
Individual Tree ◽  
Phenotypic Correlations ◽  
Age Related ◽  
Optimum Selection ◽  
Heritability Estimates ◽  
Optimum Selection Age

Genetic and phenotypic parameters for core wood density of Pinus taeda L. were estimated for ages ranging from 5 to 25 years at two sites in southern United States. Heritability estimates on an individual-tree basis for core density were lower than expected (0.20–0.31). Age–age genetic correlations were higher than phenotypic correlations, particularly those involving young ages. Age–age genetic correlations were high, being greater than 0.75. Age–age genetic correlations had a moderately linear relationship, while age–age phenotypic correlations had a strong linear relationship with natural logarithm of age ratio. Optimum selection age for core density was estimated to be 5 years when calculations were based on both genetic and phenotypic correlations. However, age 5 was the youngest examined in this study and optimum selection age may be younger than 5. Generally, the optimum selection age was robust to changes in breeding phase and assumptions concerning age-related variation in heritability estimates. Early selection for core density would result in a correlated increase in earlywood density but little progress in latewood density or latewood proportion at maturity.

Early genetic testing of coastal Douglas-fir for Swiss needle cast tolerance

2005 ◽  
Vol 35 (3) ◽  
pp. 521-529 ◽  
Author(s):  
Fatih Temel ◽  
G R Johnson ◽  
W T Adams
Keyword(s):  
Genetic Correlations ◽  
Douglas Fir ◽  
Seedling Stage ◽  
Family Selection ◽  
Mature Trees ◽  
Individual Tree ◽  
Needle Cast ◽  
Swiss Needle Cast ◽  
Early Testing ◽  
Fungal Dna

The possibility of early testing coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) for Swiss needle cast (SNC; caused by Phaeocryptopus gaeumannii (Rohde) Petrak) tolerance was investigated using 55 Douglas-fir families from western Oregon. Seedlings were inoculated with P. gaeumannii naturally in the field and were visually scored for a variety of SNC symptom traits (i.e., needle and foliage color, and retention) at the seedling stage (age 2) and in "mature" (ages 10 and 12) trees at two test sites for both the seedling and mature ages. Seedlings were also assessed in the laboratory for SNC symptom traits, for proportion of needle stomata occluded with pseudothecia (PSOP), and for amount of P. gaeumannii DNA in needles. Although families differed significantly at both ages for all SNC symptom traits and for PSOP, they did not differ for amount of fungal DNA. Thus, genetic variation in SNC symptoms appears to be primarily due to differences in tolerance to the disease rather than to resistance to infection per se. Estimated individual-tree heritabilities for SNC symptom traits were low to moderate (mean hi2 = 0.19, range 0.06–0.37) at both ages, and within each age-class these traits were moderately to strongly genetically correlated (mean rA = 0.69, range 0.42–0.95). Type B genetic correlations between SNC symptom traits in seedlings and mature trees ranged from 0 to 0.83 and were weakest for traits measured in the laboratory. Genetic gain estimates indicated that family selection for SNC tolerance (i.e., greener needles or greater foliage retention) at the seedling stage can be very effective in increasing tolerance in older trees.

scholarly journals Genetic control of stiffness of standing Douglas fir; from the standing stem to the standardised wood sample, relationships between modulus of elasticity and wood density parameters. Part I

1999 ◽  
Vol 56 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Cécile Mamdy ◽  
Philippe Rozenberg ◽  
Alain Franc ◽  
Jean Launay ◽  
Nicolas Schermann ◽  
...  
Keyword(s):  
Genetic Control ◽  
Wood Density ◽  
Modulus Of Elasticity ◽  
Wood Sample ◽  
Douglas Fir

Genetic variation in tree structure and its relation to size in Douglas-fir. I. Biomass partitioning, foliage efficiency, stem form, and wood density

1994 ◽  
Vol 24 (6) ◽  
pp. 1226-1235 ◽  
Author(s):  
J. B. St.Clair
Keyword(s):  
Genetic Variation ◽  
Leaf Area ◽  
Wood Density ◽  
Harvest Index ◽  
Genetic Correlations ◽  
Douglas Fir ◽  
Biomass Partitioning ◽  
Alternative Measure ◽  
Sapwood Area ◽  
Stem Size

Genetic variation and covariation among traits of tree size and structure were assessed in an 18-year-old Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco) genetic test in the Coast Range of Oregon. Considerable genetic variation was found in size, biomass partitioning, and wood density, and genetic gains may be expected from selection and breeding of desirable genotypes. Estimates of heritability for partitioning traits, including harvest index, were particularly high. Foliage efficiency (stem increment per unit leaf area) was strongly correlated with harvest index and may represent an alternative measure of partitioning to the stem. Estimates of foliage efficiency where leaf area was estimated based on stem diameter or sapwood area were unrelated to foliage efficiency where leaf area was measured directly. Strong negative genetic correlations were found between harvest index and stem size, and between wood density and stem size. Achieving simultaneous genetic gain in stem size and either harvest index or wood density would be difficult.

Genetic control of wood density profile in young Douglas-fir

1991 ◽  
Vol 21 (6) ◽  
pp. 935-939 ◽  
Author(s):  
J. A. Loo-Dinkins ◽  
J. S. Gonzalez
Keyword(s):  
Relative Density ◽  
Genetic Control ◽  
Density Profile ◽  
Douglas Fir ◽  
Breast Height ◽  
Cambial Age ◽  
Sib Families ◽  
Progeny Tests ◽  
Selection For ◽  
The Difference

The relative density profile from pith to bark was examined in young Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stems at 1.3, 0.7, and 0.4 m above the ground. The trees represented 22 half-sib families growing at two progeny test locations. The objective was to evaluate the reliability of wood samples taken from below breast height (1.3 m) for selection for relative density in young coastal Douglas-fir progeny tests. The relative density profile appeared to be different for the first 6 or 7 years from the pith at the different sampling heights, but the difference decreased with cambial age. Genetic correlation estimates were sufficiently high to indicate identical genetic control at the three sampling heights, but heritability estimates were higher at 1.3 and 0.7 m than at 0.4 m. Sampling at 0.7 m is as effective as at 1.3 m. This allows reliable selection 1 to 2 years earlier than by sampling at 1.3 m.

scholarly journals Genetic Variation in the Microfibril Angle of Loblolly Pine From Two Test Sites

2004 ◽  
Vol 28 (4) ◽  
pp. 196-204 ◽  
Author(s):  
Jennifer H. Myszewski ◽  
Floyd E. Bridgwater ◽  
William J. Lowe ◽  
Thomas D. Byram ◽  
Robert A. Megraw
Keyword(s):  
Specific Gravity ◽  
Loblolly Pine ◽  
Combining Ability ◽  
Growth Traits ◽  
Genetic Relationships ◽  
Wood Quality ◽  
Genetic Correlations ◽  
Microfibril Angle ◽  
Narrow Sense Heritability ◽  
Individual Tree

Abstract In recent years, several studies have examined the effect of microfibril angle (MFA) on wood quality. However, little research has been conducted upon the genetic mechanisms controlling MFA. In this study, we examined the heritability of MFA in loblolly pine, Pinus taeda L.,and its genetic relationships with height, diameter, volume, and specific gravity. Increment cores were collected at breast height from 20 to 25 progeny from each of 12 to 17 crosses (among 11 parents) in two modified partial-diallels in different locations in southern Arkansas. Specific gravitywas measured on segments containing rings 1 through 5 and on segments containing rings 6 through 20. MFA was measured on the earlywood and latewood sections of rings 4, 5, 19, and 20. Rings 4 and 5 were chosen as representative of core wood and rings 19 and 20 as representative of outer wood. Analyses of variance revealed statistically significant genetic and environmental influences on MFA. Significant general combining ability (GCA), specific combining ability (SCA), and SCA × block effects indicated that there are both additive and nonadditive genetic influences on MFA. Individual-tree, narrow-sense heritability estimates were variable, ranging from 0.17 for earlywood (ring) 4 MFA to 0.51 for earlywood (ring) 20 MFA. Genetic correlations between MFA, specific gravity, and the growth traits were nonsignificant due to large estimated standard errors. South.J. Appl. For. 28(4):196–204.

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