Correlated responses of height increment and components of increment in 2-year-old Douglas-fir

1989 ◽  
Vol 19 (9) ◽  
pp. 1124-1130 ◽  
Author(s):  
Zeki Kaya ◽  
R. K. Campbell ◽  
W. T. Adams
Keyword(s):  
Coastal Region ◽  
Common Garden ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Early Selection ◽  
Growing Seasons ◽  
Bud Set ◽  
Selection For ◽  
The Difference ◽  
Phenological Event

The consequences for growth and phenology of early selection for height or its growth components were evaluated in 160 open-pollinated families of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) from southwestern Oregon. Seedlings from two inland and two coastal populations (40 families each) were grown for two growing seasons in a common garden. Predicted response to selection suggests that risk of low juvenile–mature correlation and maladaptation with early selection would be less in the inland than in the coastal region. A phenological event that influences a common growth pattern seems to account for the difference in response. Early bud set in the 1st year was genetically correlated with larger overwintering buds in seedlings from both inland and coastal regions. These larger buds yielded a large increment of predetermined growth in the 2nd year, followed by little or no free growth and early bud set. Seedlings with late bud set in the 1st year had the converse pattern. Inland seedlings set buds much earlier on the average than did coastal seedlings; hence seedlings from the two regions had different growth patterns. Risks that can attend early selection for height generally would be decreased in both regions by selecting for predetermined growth, but several qualifications are discussed.

Genetic variation in fall cold hardiness in coastal Douglas-fir in western Oregon and Washington

2006 ◽  
Vol 84 (7) ◽  
pp. 1110-1121 ◽  
Author(s):  
J. Bradley St. Clair
Keyword(s):  
Genetic Variation ◽  
Cold Hardiness ◽  
Environmental Gradients ◽  
Large Population ◽  
Common Garden ◽  
Cold Season ◽  
Douglas Fir ◽  
Bud Burst ◽  
Population Differences ◽  
Bud Set

Genetic variation in fall cold damage in coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii ) was measured by exposing excised branches of seedlings from 666 source locations grown in a common garden to freezing temperatures in a programmable freezer. Considerable variation was found among populations in fall cold hardiness of stems, needles, and buds compared with bud burst, bud set, and biomass growth after 2 years. Variation in fall cold hardiness was strongly correlated (r = 0.67) with cold-season temperatures of the source environment. Large population differences corresponding with environmental gradients are evidence that natural selection has been important in determining genetic variation in fall cold hardiness, much more so than in traits of bud burst (a surrogate for spring cold hardiness), bud set, and growth. Seed movement guidelines and breeding zones may be more restrictive when considering genetic variation in fall cold hardiness compared with growth, phenology, or spring cold hardiness. A regional stratification system based on ecoregions with latitudinal and elevational divisions, and roughly corresponding with breeding zones used in Oregon and Washington, appeared to be adequate for minimizing population differences within regions for growth and phenology, but perhaps not fall cold hardiness. Although cold hardiness varied among populations, within-population and within-region variation is sufficiently large that responses to natural or artificial selection may be readily achieved.

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.

Genetic control of bud phenology in pole-size trees and seedlings of coastal Douglas-fir

1993 ◽  
Vol 23 (6) ◽  
pp. 1043-1051 ◽  
Author(s):  
Peng Li ◽  
W.T. Adams
Keyword(s):  
Genetic Control ◽  
Growth Traits ◽  
Douglas Fir ◽  
Bud Burst ◽  
Age Classes ◽  
Breeding Programs ◽  
Bud Set ◽  
Bud Phenology ◽  
Selection For ◽  
Lateral Branches

The extent to which bud phenology is genetically controlled and related to growth traits was examined in seedlings and pole-size trees of coastal Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco). Data on bud burst, bud set, and stem growth were collected from pole-size trees of 60 open-pollinated families growing in four plantations, and from seedlings of 45 of these same families growing in three trials. In both age-classes, bud burst was under moderate to strong genetic control (h2 ≥ 0.44) and family breeding values were stable across test environments, indicating that this trait could be readily altered in breeding programs. Bud set was inherited strongly in pole-size trees (h2 = 0.81) but weakly in seedlings (h2 < 0.30). Both bud burst and bud set were positively correlated with growth in seedlings and pole-size trees. Thus, selection for greater growth at either age-class is expected to delay bud burst and bud set. We also evaluated the accuracy of two alternatives for assessing bud burst phenology in pole-size trees compared with the traditional method. We show that bud-burst date on lateral branches can be used to accurately rank both individuals and families for bud-burst date on less accessible leader shoots. In addition, we found that families can be ranked for mean bud-burst date by the proportion of trees per family that have flushed on a given scoring day. This method is only effective, however, when between 25 and 75% of all trees in the test have flushed at the time of scoring.

The effect of nursery blackout application on Sitka spruce seedlings

1996 ◽  
Vol 26 (12) ◽  
pp. 2201-2213 ◽  
Author(s):  
C.D.B. Hawkins ◽  
A.M. Eastham ◽  
T.L. Story ◽  
R.Y.N. Eng ◽  
D.A. Draper
Keyword(s):  
Cold Hardiness ◽  
Common Garden ◽  
Sitka Spruce ◽  
Day Length ◽  
Root Weight ◽  
Growing Seasons ◽  
Control Stock ◽  
Bud Set ◽  
Terminal Bud ◽  
Dynamic Treatment

Sitka spruce (Piceasitchensis (Bong.) Carrière) seedlings were cultured using two nursery methods of blackout (short photoperiod) application: static treatment (constant day length of 14.28 h) and dynamic treatment (day length varying over length of experiment, with a mean of 14.28 h). Both methods when compared with a control (natural day length) reduced seedling height by inducing terminal bud set, increased seedling root weight, and decreased shoot to root and sturdiness ratios. Both static and dynamic blackout treatment seedlings had 26 and 30% lammas flush, respectively. Compared with control, both methods accelerated cold hardiness acquisition. After winter storage at −2 °C, treated seedlings flushed sooner than did control stock under light:dark temperatures of 25:20 °C. Under a cooler regime, 15:5 °C, differences among treatments were not significant. After planting in a common garden trial, terminal bud phenology had a range of treatment responses. Control seedlings flushed later and set bud sooner. Dynamic treatment seedlings' bud set phenology was nearest to that of controls. At a common garden trial and a reforestation site, blackout-treated seedlings had greater first-season terminal height increment. Planting check was observed for all treatments in the field during the second and third growing seasons. After five field seasons there was no height difference among treatments, and survival averaged 87%. Groundline stem diameter was never different among treatments. Biologically, the dynamic treatment is intermediate between the static and control treatments, but the static treatment is recommended because it is easier to apply in the nursery, and differences between the dynamic and static treatments were minimal.

Growth and Water Relations of Douglas Fir (Pseudotsuga menziesii) Seedlings under Different Weed Control Regimes

Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 653-662 ◽  
Author(s):  
Michael Newton ◽  
David S. Preest
Keyword(s):  
Weed Control ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Stem Volume ◽  
Tree Seedlings ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Growing Seasons ◽  
Control Growth ◽  
The Difference

Growth of Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] was increased by controlling grasses and broadleaf herbs with eight herbicide regimes during the first 3 yr after planting on a well-drained moist site in the Oregon Coast Range. The greatest growth occurred if weeds were controlled in the same growing season that tree seedlings were transplanted to the field; smaller increments came from second- and third-year weed control. Growth increases attributable to early weed control continued through the fifth year, indicating that conditions during establishment strongly influenced later growth. Plots with no herbaceous vegetation had more available soil water than those with competing vegetation, and tree seedlings on these plots experienced less water stress. Irrigation in the third year increased stem diameter of seedlings in that year but had no effect thereafter. Increases in average seedling stem volume at 5 yr after transplanting were linearly related (r2 = 0.77) to the difference in observed xylem potential during the first three growing seasons after transplanting and the xylem potential at which photosynthesis ceased, −2 MPa.

Growth ofPseudotsuga menziesiiandTsuga heterophyllaseedlings along a light gradient: resource allocation and morphological acclimation

1997 ◽  
Vol 75 (9) ◽  
pp. 1424-1435 ◽  
Author(s):  
D. Mailly ◽  
J. P. Kimmins
Keyword(s):  
Leaf Morphology ◽  
Biomass Accumulation ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Low Light ◽  
Growing Seasons ◽  
Light Levels ◽  
Light Gradient ◽  
Relative Light Intensity

Silvicultural alternatives that differ in the degree of overstory removal may create shady environments that will be problematic for the regeneration of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Gradients of light in the field were used to compare mortality, growth, and leaf morphological acclimation of two conifer species of contrasting shade tolerances: Douglas-fir and western hemlock (Tsuga heterophylla (Raf.) Sarg.). Results after two growing seasons indicated that Douglas-fir mortality occurred mainly at relative light intensity (RLI) below 20%, while western hemlock mortality was evenly distributed along the light gradient. Height, diameter, and biomass of the planted seedlings increased with increasing light for both species but at different rates, and maximum biomass accumulation always occurred in the open. Douglas-fir allocated more resources to stem biomass than western hemlock, which accumulated more foliage biomass. Increases in specific leaf area for Douglas-fir seedlings occurred at RLI ≤ 0.4 and red/far red (R/FR) ratio ≤ 0.6, which appear to be the minimal optimum light levels for growth. Conversely, western hemlock seedlings adjusted their leaf morphology in a more regular pattern, and changes were less pronounced at low light levels. These results, along with early mortality results for Douglas-fir, suggest that the most successful way to artificially regenerate this species may be by allowing at least 20% of RLI for ensuring survival and at least 40% RLI for optimum growth. Key words: light, light quality, leaf morphology, acclimation.

The effect of exposure to conspecifics on restlessness in the parasitoid wasp Nasonia vitripennis (Hymenoptera: Pteromalidae)

2007 ◽  
Vol 139 (5) ◽  
pp. 678-684 ◽  
Author(s):  
B.H. King
Keyword(s):  
Habitat Quality ◽  
Parasitoid Wasp ◽  
Poor Quality ◽  
The Other ◽  
Dispersal Ability ◽  
Nasonia Vitripennis ◽  
Adult Females ◽  
Selection For ◽  
The Difference ◽  
Abundance And Distribution

AbstractWhen habitat quality is variable, there should be strong selection for the ability to detect and respond to the variation. Adult females of the parasitoid wasp Nasonia vitripennis (Walker) are known to increase their restlessness (the proportion of time in locomotion) both during and after exposure to a poor quality host. Doing so provides a mechanism for leaving a poor host and potentially finding a better host. This study examined whether restlessness also changes in response to competition as indicated by the presence of adult conspecifics. Both restlessness and the probability of dispersing across an inhospitable environment were greater when a female was with another female than when she was alone. However, restlessness did not remain elevated after the other female was removed. In contrast with females, restlessness of males did not increase either during or after exposure to other males, and the probability of dispersing across an inhospitable environment was unaffected by the presence of another male. The difference between females and males may be related to differences in dispersal ability and in the abundance and distribution of hosts versus mates.

scholarly journals Very early selection for solid wood quality: screening for early winners

2009 ◽  
Vol 66 (6) ◽  
pp. 601-601 ◽  
Author(s):  
Luis A. Apiolaza
Keyword(s):  
Wood Quality ◽  
Solid Wood ◽  
Early Selection ◽  
Selection For

Economic optimum plant density of irrigated early-maturity soybean in southern Alberta

2021 ◽  
Author(s):  
Tram T.N. Thai ◽  
Danny G. Le Roy ◽  
Manjula S. Bandara ◽  
James E. Thomas ◽  
Francis J Larney
Keyword(s):  
Plant Density ◽  
Profit Maximization ◽  
Seeding Density ◽  
Early Maturity ◽  
Growing Seasons ◽  
Southern Alberta ◽  
Soybean Genotypes ◽  
Glycine Max L ◽  
The Difference ◽  
Lower Plant

With soybean [Glycine max (L.) Merr.] seed cost increasing in Alberta, understanding economic optimum plant density (EOPD) could help growers save on input expenses. A study was conducted at two irrigated locations in southern Alberta (Bow Island and Lethbridge), in three growing seasons (2014–16), using two maturity group (MG) 00 soybean genotypes, two row spacings (RS; narrow, 17.5 cm; wide, 35 cm), and three seeding densities (SD; 30, 50 and 80 seeds m-2). Exponential plant density-yield relationships were used to estimate EOPD. The earlier MG 00.4 genotype compensated yield at lower plant density (39 vs. 43 plants m-2) and emergence (74 vs. 80%) than the later MG 00.8 genotype. The EOPD gaps between environments, genotypes, and RS were minimal (from 1–3 plants m-2), resulting in only 1.3–2.0% differences in grain yield (37–56 kg ha-1), and gross revenue at EOPD ($16–24 ha-1). The overall EOPD estimate was 46 plants m-2, regardless of environment, genotype or RS. The study highlighted the difference between agronomic production and profit maximization in choosing an optimum plant density, and the need to establish a seeding density calculator for irrigated soybean in southern Alberta.

scholarly journals Early generation selection strategy for yield and yield components in white oat

2005 ◽  
Vol 62 (4) ◽  
pp. 357-365 ◽  
Author(s):  
Giovani Benin ◽  
Fernando Irajá Félix de Carvalho ◽  
Antônio Costa de Oliveira ◽  
Claudir Lorencetti ◽  
Igor Pires Valério ◽  
...  
Keyword(s):  
Grain Yield ◽  
Indirect Selection ◽  
Grain Weight ◽  
Yield Potential ◽  
High Yield ◽  
Direct Selection ◽  
Selection Strategy ◽  
Breeding Method ◽  
Growing Seasons ◽  
Selection For

Several studies have searched for higher efficiency on plant selection in generations bearing high frequency of heterozygotes. This work aims to compare the response of direct selection for grain yield, indirect selection through average grain weight and combined selection for higher yield potential and average grain weight of oat plants (Avena sativa L.), using the honeycomb breeding method. These strategies were applied in the growing seasons of 2001 and 2002 in F3 and F4 populations, respectively, in the crosses UPF 18 CTC 5, OR 2 <FONT FACE=Symbol>´</FONT> UPF 7 and OR 2 <FONT FACE=Symbol>´</FONT> UPF 18. The ten best genetic combinations obtained for each cross and selection strategy were evaluated in greenhouse yield trials. Selection of plants with higher yield and average grain weight might be performed on early generations with high levels of heterozygosis. The direct selection for grain yield and indirect selection for average grain weight enabled to increase the average of characters under selection. However, genotypes obtained through direct selection presented lower average grain weight and those obtained through the indirect selection presented lower yield potential. Selection strategies must be run simultaneously to combine in only one genotype high yield potential and large grain weight, enabling maximum genetic gain for both characters.

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