Genetic variation of wood shrinkage in a progeny test of coastal Douglas-fir

1994 ◽  
Vol 24 (8) ◽  
pp. 1734-1740 ◽  
Author(s):  
Mathew P. Koshy ◽  
Donald T. Lester
Keyword(s):  
Genetic Variation ◽  
Douglas Fir ◽  
Genetic Effects ◽  
High Variability ◽  
Progeny Test ◽  
Longitudinal Shrinkage ◽  
Breast Height ◽  
Sib Families ◽  
Ring Position

Directional (longitudinal, tangential, and radial) and volumetric wood shrinkage were analyzed in 413 trees belonging to 48 full-sib families (four pollen and 12 seed parents) from an 18-year-old coastal Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco) progeny test. Six samples per ring position (ring positions 1–5 from pith along stem radii), with two rings in each ring position, were examined in a bolt taken at breast height from the tree. Genetic effects were minimal for shrinkage, except for longitudinal shrinkage at ring positions 1 and 2. High variability was expressed among trees within plots and among samples within trees (circumferential variation). The lack of statistically significant family variance eliminates the possibility of improving the shrinkage traits by genetic means, except for longitudinal shrinkage in the first few rings. However, the high amount of variability expressed between trees within plots and between samples within trees warrants special attention for achieving uniformity of wood. Much of this variability can be reduced by silvicultural methods.

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 Performance and Genetic Parameters of Somatic and Zygotic Progenies of Coastal Douglas-fir at 71/2-Years across Washington and Oregon, USA

2009 ◽  
Vol 58 (1-6) ◽  
pp. 212-219 ◽  
Author(s):  
C. A. Dean ◽  
D. E. Welty ◽  
G. E. Herold
Keyword(s):  
Genetic Parameters ◽  
Total Population ◽  
Douglas Fir ◽  
Stem Volume ◽  
Stem Height ◽  
Single Tree ◽  
Breast Height ◽  
Sib Families ◽  
Western Washington ◽  
Clonal Heritability

Abstract Five genetic tests involving 37 somatic clones of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) were planted March 2000 in Weyerhaeuser plantations across western Washington and Oregon States, USA. Four of the tests are in Longview, Twin Harbors and Vail regions of Washington, and one test is in Springfield, Oregon. Each test is based on single-tree plots with 12 randomized complete-blocks. The 37 coastal Douglas-fir clones were propagated by somatic embryogenesis from four full-sib families. Zygotic seedlings from two of these full-sib families were planted across all five tests to allow comparison between somatic and zygotic trees of the same pedigree. Results are reported for survival, stem height, diameter at breast-height (DBH), volume and stem sinuosity at 71/2- years. On average the total population of 37 somatic clones had less stem sinuosity, but grew more slowly than zygotic trees across the five tests studied. However, the best 20% of somatic clones for growth produced 25% greater stem volume at 71/2-years than the zygotic fullsib families. Height had a clonal heritability of 0.61 ± 0.09, DBH 0.64 ± 0.06, volume 0.58 ± 0.08 and stem sinuosity 0.26 ± 0.06. The clonal genetic correlation between height and DBH at 71/2-years was 0.98 ± 0.01, while stem sinuosity was adversely genetically correlated with growth. Clonal performance for growth and stem sinuosity was stable across tests with overall between-test correlations of 0.96 to 0.98. This clonal stability resulted in little variance due to clone x test interactions.

scholarly journals Potencial de mejoramiento genético en Juglans neotropica Diels, a los 10 meses de edad en Tunshi, Chimborazo/Potential of Genetic Improvement in Juglans neotropica Diels, at 10 months of age in Tunshi, Chimborazo

2020 ◽  
Author(s):  
R. A. Ramos Veintimilla ◽  
O. Murillo Gamboa ◽  
L. A. Gallo
Keyword(s):  
Genetic Variation ◽  
Genetic Improvement ◽  
Genetic Parameters ◽  
Forest Ecosystems ◽  
Progeny Test ◽  
Annual Rainfall ◽  
Average Temperature ◽  
Commercial Use ◽  
Sib Families ◽  
Degraded Forest Ecosystems

La ESPOCH en 2 016 inició un programa de mejoramiento genético con Juglans neotropica Diels, con el objetivo de potencializar su uso comercial y restaurar ecosistemas forestales degradados en la sierra ecuatoriana. En febrero de 2 018, en la granja Tunshi - ESPOCH, con una temperatura media anual de 13,8 ∘C, precipitación media anual de 835,6 mm, altitud de 2 700 msnm y en estepa espinosa Montano Bajo (Holdrige 1993). Se estableció un ensayo genético con 38 familias de medios hermanos, provenientes de las procedencias Chimborazo, Tungurahua, Bolívar y Otras. En un diseño de bloques incompletos al azar, con 19 repeticiones; la unidad experimental fue una planta. Se evaluó la supervivencia, altura total (cm), diámetro del fuste a 5 cm del suelo, y presencia temprana de ramas; Los datos fueron analizados en SELEGEN, para obtener los parámetros genéticos. A los 10 meses de evaluación, la heredabilidad individual y familiar son aún bajos, pero significativos en las variables de crecimiento (procedencias > 0,38 para altura total y > 0,31 para DAC). la variación genética entre familias duplica a la variación genética entre procedencias (2,29 a 1,15, respectivamente). El ranking entre procedencias en las variables evaluadas, encabeza la procedencia Chimborazo, mientras que la procedencia Tungurahua ocupa casi siempre los últimos lugares. La colección base de mejoramiento de J. neotropica, plantada en la ESPOCH presenta una amplia variabilidad genética. La táctica de reunir al menos 10 familias por procedencia y por lo menos 3 procedencias, ha mostrado eficiencia para contar con una población base de calidad y plantar una fuente semillera genéticamente fuerte para esta especie importante. In 2 016 ESPOCH started a breeding program with Juglans neotropica Diels, with the intent of developing its commercial use and restoring degraded forest ecosystems in the Ecuadorian highlands. In February 2 018, in the farm Tunshi ESPOCH with an average temperature of 13.8 ∘ C, annual rainfall of 835.6 mm, altitude of 2700 m. one progeny test comprised 38 sib families, sourced from Chimborazo, Tungurahua, Bolivar and other sources. In a design of randomized incomplete blocks, with 19 repetitions; The experiment evaluated plant survival, overall height (cm), stem diameter 5 cm of soil, and early presence of side branches; Genetic parameters were obtained in SELEGEN. At 10 months of evaluation, heritability individual and family are still low, but significant in the variables of growth analyzed (provenances> 0.38 for total height and> 0.31 for DAC). Genetic variation between families duplicates genetic variation among provenances (2.29 to 1.15). The ranking among provenances in all variables is lead by Chimborazo (CH) plants, while the Tungurahua (TUN) almost always origin occupies the last places in growth and vigor. The genetic improvement base collection of J. neotropica planted by ESPOCH is extremely rich and with a wide genetic variability. The strategy of bringing together at least 10 families per provenance and no less than 3 sources, has proved efficient to capture a base population. Palabras claves: Juglans neotropica Diels, procedencias, ensayo de progenies, Mejoramiento Genético. Keywords: Juglans neotropica Diels, provenance, progeny test, Breeding.

Wachstum und Wertleistung der Douglasie in Abhängigkeit von der Standraumgestaltung

2012 ◽  
Vol 163 (3) ◽  
pp. 96-104 ◽  
Author(s):  
Joachim Klädtke ◽  
Ulrich Kohnle ◽  
Edgar Kublin ◽  
Andreas Ehring ◽  
Hans Pretzsch ◽  
...  
Keyword(s):  
Wood Quality ◽  
Volume Growth ◽  
Static Stability ◽  
Douglas Fir ◽  
Breast Height ◽  
Monetary Analysis ◽  
Starting Conditions ◽  
Tree Number ◽  
Clear Differentiation ◽  
Further Development

Growth and value production of Douglas-fir under varying stand densities The investigation is focused on the effects of initial tree number and thinning on growth and value performance of Douglas-fir stands. Data base is a coordinated Douglas-fir spacing experiment in South Germany, started 40 years ago and comprising variants of tree numbers with 500, 1,000, 2,000 and 4,000 Douglas-firs per hectare. The treatment was performed according to a standardized experiment program. The results show that at low initial tree numbers, the diameter on breast height (DBH) of (pre)dominant trees at the beginning of the observations (with 12 m top height) is bigger than at higher initial plant numbers. Accordingly, the quotient of height (H) to DBH (as an indicator for tree's static stability) is lower. The further development of DBH and H/DBH quotient is decisively determined by stand treatment, which superimposes the effect of the initial tree number. The total volume growth shows a clear differentiation, too, the variants with initially high tree numbers appearing on top. In the monetary analysis, this ranking is reversed: despite a supposed inferior wood quality, the variants with lower initial tree numbers clearly outperform the ones with higher numbers in terms of value. From these results, the following silvicultural recommendations for Douglas-fir can be derived: the initial tree numbers should be in the range from 1,000 to 2,000 plants per hectare. On technically not accessible sites, even lower tree numbers may come into question. The strong influence of stand treatment on DBH and H/DBH development highlights the problem of postponed thinnings, for this causes growth and stability losses even under favorable starting conditions in terms of competition.

scholarly journals The expression of additive and nonadditive genetic variation under stress.

Genetics ◽  
1995 ◽  
Vol 140 (3) ◽  
pp. 1149-1159
Author(s):  
M W Blows ◽  
M B Sokolowski
Keyword(s):  
Genetic Variation ◽  
Development Time ◽  
Genetic Effects ◽  
Hybrid Breakdown ◽  
Bristle Number ◽  
Gene Complexes ◽  
General Expectation ◽  
Faster Development ◽  
Seven Generations ◽  
Additive Genetic Effects

Abstract Experimental lines of Drosophila melanogaster derived from a natural population, which had been isolated in the laboratory for approximately 70 generations, were crossed to determine if the expression of additive, dominance and epistatic genetic variation in development time and viability was associated with the environment. No association was found between the level of additive genetic effects and environmental value for either trait, but nonadditive genetic effects increased at both extremes of the environmental range for development time. The expression of high levels of dominance and epistatic genetic variation at environmental extremes may be a general expectation for some traits. The disruption of the epistatic gene complexes in the parental lines resulted in hybrid breakdown toward faster development and there was some indication of hybrid breakdown toward higher viability. A combination of genetic drift and natural selection had therefore resulted in different epistatic gene complexes being selected after approximately 70 generations from a common genetic base. After crossing, the hybrid populations were observed for 10 generations. Epistasis contributed on average 12 hr in development time. Fluctuating asymmetry in sternopleural bristle number also evolved in the hybrid populations, decreasing by > 18% in the first seven generations after hybridization.

scholarly journals Evaluating indirect genetic effects of siblings using singletons

2021 ◽  
Author(s):  
Laurence Howe ◽  
David Evans ◽  
Gibran Hemani ◽  
George Davey Smith ◽  
Neil Martin Davies
Keyword(s):  
Genetic Variation ◽  
Educational Attainment ◽  
Family Environment ◽  
Phenotypic Variation ◽  
Molecular Genetic ◽  
Genetic Effects ◽  
Polygenic Risk Score ◽  
Indirect Genetic Effects ◽  
Molecular Genetic Evidence ◽  
Older Siblings

Estimating effects of parental and sibling genotypes (indirect genetic effects) can provide insight into how the family environment influences phenotypic variation. There is growing molecular genetic evidence for effects of parental phenotypes on their offspring (e.g. parental educational attainment), but the extent to which siblings affect each other is currently unclear.Here we used data from samples of unrelated individuals, without (singletons) and with biological full-siblings (non-singletons), to investigate and estimate sibling effects. Indirect genetic effects of siblings increase (or decrease) the covariance between genetic variation and a phenotype. It follows that differences in genetic association estimates between singletons and non-singletons could indicate indirect genetic effects of siblings.We used UK Biobank data to estimate polygenic risk score (PRS) associations for height, BMI and educational attainment in singletons (N = 50,143) and non-singletons (N = 328,549). The educational attainment PRS association estimate was 12% larger (95% C.I. 3%, 21%) in the non-singleton sample than in the singleton sample, but the height and BMI PRS associations were consistent. Birth order data suggested that the difference in educational attainment PRS associations was driven by individuals with older siblings rather than firstborns. The relationship between number of siblings and educational attainment PRS associations was non-linear; PRS associations were 24% smaller in individuals with 6 or more siblings compared to the rest of the sample (95% C.I. 11%, 38%). We estimate that a 1 SD increase in sibling educational attainment PRS corresponds to a 0.025 year increase in the index individual’s years in schooling (95% C.I. 0.013, 0.036).Our results suggest that older siblings influence the educational attainment of younger siblings, adding to the growing evidence that effects of the environment on phenotypic variation partially reflect social effects of germline genetic variation in relatives.

Effects of thinning and urea fertilization on the distribution of area increment along the boles of Douglas-fir at Shawnigan Lake, British Columbia

1984 ◽  
Vol 14 (6) ◽  
pp. 879-884 ◽  
Author(s):  
A. J. Thomson ◽  
H. J. Barclay
Keyword(s):  
Growth Rate ◽  
Radial Growth ◽  
Temporal Trend ◽  
Douglas Fir ◽  
Regression Methods ◽  
Average Area ◽  
Breast Height ◽  
Urea Fertilization ◽  
Measurement Period ◽  
Growth Distribution

The effects of fertilization and thinning of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) on the distribution of area increment along the bole were assessed using radial growth measurements 6 and 9 years after treatment. Within treatments, the average area increment per tree was linearly related to diameter at breast height, and this relationship was used to evaluate the effects of treatment on growth rate. Fertilization had the greatest effect on average area increment, and for a particular fertilization regime, thinning increased the response. Thinning modified the distribution of growth over the bole of all trees and increased butt flare, especially in smaller trees. The effect declined from the 4- to 6-year measurement period to the 7-to 9-year measurement period. Fertilization had no consistent effect on growth distribution. The regression methods used in this study provided a more sensitive measure of form changes than previous methods, were independent of size distribution, and facilitated extrapolations and evaluation of temporal trend.

A Multipoint Felled-Tree Validation of Height–Age Modeled Growth Rates

2020 ◽  
Vol 66 (3) ◽  
pp. 275-283 ◽  
Author(s):  
Halli Hemingway ◽  
Mark Kimsey
Keyword(s):  
Growth Rates ◽  
Rocky Mountain ◽  
Site Index ◽  
Douglas Fir ◽  
Alternative Methods ◽  
Forest Site ◽  
Site Productivity ◽  
Site Factors ◽  
Forest Management Planning ◽  
Breast Height

Abstract Accurate measures of forest site productivity are essential for forest-management planning. The most common measure of site productivity is breast height–age site index (BHASI)—the expected height at a reference age. Error from including early growth in productivity estimates and limited applicability of any one BHASI model warrant development of alternative methods. Exploring alternatives may only be necessary if regional BHASI models are not accurately predicting growth rates. We compared modeled height growth rates for Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) to felled-tree measurements to evaluate relative performance of a regional BHASI model. An orthogonal sampling design ensured samples were collected across a range of site factors known to influence Douglas-fir growth rates. Growth rates for each 10 m section were calculated and compared to BHASI modeled growth rates. The regional BHASI model underpredicted growth rates from breast height to 30 m. Observed growth rates from 10 to 30 m accounted for the majority of underprediction relative to BHASI modeled growth rates. An alternative multipoint method of defining site productivity is described. More research comparing BHASI and alternative methods is needed, given the growth rate error associated with one-point site productivity assessment.

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