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

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.

1991 ◽  
Vol 21 (12) ◽  
pp. 1801-1807 ◽  
Author(s):  
Jesus Vargas-Hernandez ◽  
W. T. Adams

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.


IAWA Journal ◽  
2005 ◽  
Vol 26 (3) ◽  
pp. 309-324 ◽  
Author(s):  
A.T. Grotta ◽  
B.L. Gartner ◽  
S.R. Radosevich ◽  
M. Huso

To better understand the influence of competition on wood formation and wood quality in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco), patterns of cambial growth and latewood production were examined for one growing season in 15-year-old plantations with similar densities but differing Douglas-fir/red alder (Alnus rubra Bong.) ratios. The treatments consisted of plots having different proportions of Douglas-fir vs. red alder, different red alder planting dates, and one of two total planting densities. Cambial growth was tracked using the pinning method. Cambial activity in most trees began between May 12 and May 23, and ended between August 27 and September 10. Mean date of transition to latewood was July 6. In the treatment with the highest mean red alder basal area, Douglas- fir trees began radial growth later and ended earlier in the year than those in pure Douglas-fir stands. There was no evident effect of competition from red alder on the duration of cambial activity in treatments with intermediate to low red alder basal areas. In all treatments, the duration of radial growth was shorter in smaller-diameter trees. Early transition to latewood production was also associated with higher red alder basal area. Percent latewood was unaffected by treatment, but it was dependent on the date of a tree's transition to latewood production.


1994 ◽  
Vol 24 (9) ◽  
pp. 1864-1870 ◽  
Author(s):  
Peng Li ◽  
W.T. Adams

The objectives of this study were to (i) determine the extent of genetic variation and genetic control of cambial phenology in coastal Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco), (ii) assess the degree to which cambial phenology is genetically related to bud-burst timing, (iii) examine genetic relationships between cambial phenology and growth traits, and (iv) evaluate the potential for indirectly altering cambial phenology in breeding programs when selection is for stem volume. Dates of diameter-growth initiation and cessation, and duration of diameter growth (i.e., cambial phenology traits), as well as diameter increment for a single growing season (1987, at the age of 15 years from seed), were estimated from cumulative diameter growth curves of individual trees of 60 open-pollinated families growing in one plantation. Data on stem height and diameter (DBH), and date of bud burst in 1987 were also collected. Dates of diameter-growth initiation and cessation differed significantly among families, but had lower estimated individual heritabilities (≤0.23) than date of bud burst (0.87). Weak genetic correlations between date of bud burst and dates of diameter-growth initiation and cessation (range −0.09 to 0.26) indicate that timing of diameter growth cannot be reliably predicted from observations on the more easily measured bud burst. Cambial phenology traits were weakly correlated with 1987 diameter increment and moderately correlated with 15-year DBH and volume. Selection of parents in this study for stem volume at age 15 and subsequent crosses among them, would be expected to lead to earlier initiation of diameter growth in the offspring, and possibly later cessation as well. The practical implications of these indirect responses in terms of increased risk of frost damage are unclear, since projected changes are small (i.e., a few days).


Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1489-1506
Author(s):  
Kathleen D Jermstad ◽  
Daniel L Bassoni ◽  
Keith S Jech ◽  
Gary A Ritchie ◽  
Nicholas C Wheeler ◽  
...  

Abstract Quantitative trait loci (QTL) were mapped in the woody perennial Douglas fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) for complex traits controlling the timing of growth initiation and growth cessation. QTL were estimated under controlled environmental conditions to identify QTL interactions with photoperiod, moisture stress, winter chilling, and spring temperatures. A three-generation mapping population of 460 cloned progeny was used for genetic mapping and phenotypic evaluations. An all-marker interval mapping method was used for scanning the genome for the presence of QTL and single-factor ANOVA was used for estimating QTL-by-environment interactions. A modest number of QTL were detected per trait, with individual QTL explaining up to 9.5% of the phenotypic variation. Two QTL-by-treatment interactions were found for growth initiation, whereas several QTL-by-treatment interactions were detected among growth cessation traits. This is the first report of QTL interactions with specific environmental signals in forest trees and will assist in the identification of candidate genes controlling these important adaptive traits in perennial plants.


1999 ◽  
Vol 123 (2-3) ◽  
pp. 245-251 ◽  
Author(s):  
Bruce A. Kimball ◽  
G.R. Johnson ◽  
Dale L. Nolte ◽  
Doreen L. Griffin

Holzforschung ◽  
1970 ◽  
Vol 24 (2) ◽  
pp. 68-70 ◽  
Author(s):  
Fredric P. Riech ◽  
Kim K. Ching

2008 ◽  
Vol 38 (6) ◽  
pp. 1536-1546 ◽  
Author(s):  
Nicholas K. Ukrainetz ◽  
Kyu-Young Kang ◽  
Sally N. Aitken ◽  
Michael Stoehr ◽  
Shawn D. Mansfield

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.


1985 ◽  
Vol 15 (6) ◽  
pp. 1092-1098 ◽  
Author(s):  
Joseph E. Means ◽  
Kermit Cromack Jr ◽  
Paul C. MacMillan

Logs of Pseudotsugamenziesii (Mirb.) Franco that had been on the ground for up to 313 years were grouped into five decay classes that ranged from 1, essentially undecayed, to 5, soft and incorporated into the forest floor but still identifiable. The mean residence times on the forest floor were 7, 17, 33, 82, and 219 years for decay classes 1 through 5, respectively. The single-exponential model of litter decomposition was fitted to the density of these logs. The summation-exponential model was constructed by summing single-exponential models fitted to lignin, cellulose, and the acid detergent soluble fraction. Both models gave virtually identical, statistically significant fits to the data. Wood density of these Douglas-fir logs decreased more slowly than that of most species other researchers have studied. The single-exponential model gave mineralization rates (k) of 0.0063 and 0.0070 year−1 when residence time and decay class age (mean residence time of the decay class), respectively, were used as the independent variable. Lignin decayed more slowly than cellulose or the fraction soluble in hot acid detergent, both of which decayed at rates that were not significantly different; thus, the summation-exponential model is recommended when these constituents are of interest.


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