Clonal selection prospects in western hemlock combining rooting traits with juvenile height growth

1985 ◽  
Vol 15 (3) ◽  
pp. 488-493 ◽  
Author(s):  
G. Sam Foster ◽  
Robert K. Campbell ◽  
W. Thomas Adams
Keyword(s):  
Environmental Effect ◽  
Clonal Selection ◽  
Selection Index ◽  
Genetic Correlations ◽  
Height Growth ◽  
Western Hemlock ◽  
Rooted Cuttings ◽  
Unique Type ◽  
Genetic Components ◽  
Economic Weights

Variation in 1st-year height (HT) of western hemlock (Tsugaheterophylla (Raf.) Sarg.) rooted cuttings was partitioned into environmental and genetic components. C effects, a unique type of environmental effect, was highly significant and made up 8% of the total variation. Much of the variation (21%) resulted from genetic control of HT, producing a broad-sense heritability of 0.81. As reported in a previous paper, initial rooting ability of the rooted cuttings affected the 1st-year height growth of the trees. Genetic correlations between HT and the five rooting traits ranged from 0.37 to 0.59. Using a selection index (assuming 33% selection intensity) containing both HT and a rooting trait (VOL) would result in gains of 8–10% for HT and 20–34% for VOL, depending on relative economic weights for the two traits.

Multiple-trait selection in jack pine

1991 ◽  
Vol 21 (4) ◽  
pp. 439-445 ◽  
Author(s):  
G. W. Adams ◽  
E. K. Morgenstern
Keyword(s):  
Genetic Relationships ◽  
Selection Index ◽  
Genetic Correlations ◽  
Jack Pine ◽  
Height Growth ◽  
Quality Traits ◽  
Multiple Trait ◽  
Growing Seasons ◽  
Stem Straightness ◽  
Variance And Covariance Components

Open-pollinated jack pine (Pinusbanksiana Lamb.) families were evaluated at four sites in New Brunswick after seven growing seasons for height growth, crown quality, stem straightness, branch angle, and relative branch diameter. Variance and covariance components were estimated to determine heritability of traits and genetic correlations between traits. Results indicated that there is a negative genetic correlation between height growth and all other traits. Selection based on height growth alone would result in degradation of quality traits of secondary economic importance at this age. A restricted selection index approach was examined for family roguing in seedling seed orchards because of the adverse genetic relationships between traits. Such an approach may be used to hold secondary quality traits constant, although some loss in maximum potential genetic gain in height at 7 years is incurred.

Heritability, gain, and C effects in rooting of western hemlock cuttings

1984 ◽  
Vol 14 (5) ◽  
pp. 628-638 ◽  
Author(s):  
G. Sam Foster ◽  
Robert K. Campbell ◽  
W. Thomas Adams
Keyword(s):  
Genetic Gain ◽  
Clonal Selection ◽  
Genetic Correlations ◽  
Morphological Characteristics ◽  
Western Hemlock ◽  
Clonal Variation ◽  
Potential Bias ◽  
Correlated Responses

Analysis of clonal variation for five rooting traits of western hemlock (Tsugaheterophylla (Raf.) Sarg.) clones demonstrated that clonal variation was due to both genetic and C effects (i.e., physiological or morphological characteristics unique to the ortet because of its specific environment). The potential bias to genotypic values of clones owing to C effects was significant, but heritability and gain estimates were only slightly biased. The five rooting traits were highly heritable (H2 = 0.87–0.92), and predicted genetic gain from clonal selection was substantial. Genetic correlations between pairs of traits were generally high (0.66−0.99); therefore, when selecting for any one trait, correlated responses can be expected in other traits.

Deriving a preliminary breeding objective for commercial ostriches: an overview

2008 ◽  
Vol 48 (10) ◽  
pp. 1247 ◽  
Author(s):  
S. W. P. Cloete ◽  
A. Engelbrecht ◽  
J. J. Olivier ◽  
K. L. Bunter
Keyword(s):  
Egg Production ◽  
Selection Index ◽  
Genetic Correlations ◽  
Economic Assessment ◽  
Parameter Estimates ◽  
Chick Survival ◽  
Secondary Importance ◽  
Slaughter Weight ◽  
Economic Weights ◽  
Reproduction Traits

Ostrich farmers rely on skins and meat as their most important sources of revenue, with feathers being of secondary importance. This paper provides a summary of parameter estimates (heritabilities and genetic correlations) estimated from the resource flock held at the Oudtshoorn Research Farm. Traits considered were egg production, chick production, mature liveweight, offspring slaughter weight and skin traits. Feather weight of mature breeding birds was not included, as revenue received for this commodity is comparatively low, and mostly reliant on quality. All the traits considered were moderately to highly heritable, and reproduction traits in particular were highly variable. No substantial unfavourable genetic correlations were noted, and worthwhile gains in all traits appear to be achievable within a selection objective based on economic principles. Economic weights for key traits were obtained from a bio-economical input–output simulation model that was prepared for the industry. A simple preliminary selection index including chick production (as a hen reproductive trait) and slaughter weight (as a measure of growth) appears to be adequate for the present needs, given the limited availability of routinely recorded traits. A key performance trait that is currently missing from the economic assessment is chick survival, which is known to be low and highly variable among ostrich flocks. Further information will be added as it becomes available.

Field performance, C effects, and their relationship to initial rooting ability for western hemlock clones

1993 ◽  
Vol 23 (9) ◽  
pp. 1947-1952 ◽  
Author(s):  
A.D. Paul ◽  
G.S. Foster ◽  
D.T. Lester
Keyword(s):  
Clonal Selection ◽  
Genetic Correlations ◽  
Broad Sense ◽  
Total Variance ◽  
Western Hemlock ◽  
Regression Equations ◽  
Indirect Measure ◽  
Environmental Correlations ◽  
Rooting Ability ◽  
Initial Root

Rooted cuttings from 30 clones of western hemlock (Tsugaheterophylla (Raf.) Sarg.) were established in a field trial in northwest Oregon. A secondary cloning approach was used to partition C effects variance from genetic variance. Clonal variance in total height was significant at 1 (HT1) and 5 (HT5) years and represented 9.2% and 10.6% of the total variance at the two ages, respectively. C effects variance (among primary ramets within clones) was nonsignificant and represented 2.4% and 0% of the total variance at the two ages, respectively. Broad-sense heritabilities of HT1 and HT5 were relatively low, being 0.10 and 0.13, respectively. When calculated on a clone-mean basis, the broad-sense heritabilities increased substantially, reaching 0.53 and 0.61 for HT1 and HT5, respectively. Phenotypic correlations paired between the rooting traits and either HT1 or HT5 were low and not significant. Genetic correlations were 0.42 and 0.29 between an indirect measure of initial root system volume (VOL) and HT1 or HT5, respectively. The genetic correlations between rooting ability and HT1 or HT5 were 0.61 and 0.69, respectively. No genetic correlation existed between length of the longest initial root and field height. Environmental correlations between initial rooting traits and field height were essentially zero. Of the three initial rooting traits tested via regression analysis, VOL served as the only significant predictor or either HT1 or HT5, although the R2 values were less than 0.03, hence, the regression equations were of no practical value. Based on these results, clonal selection of western hemlock for increased early height growth should be aided by indirect selection for clonal rooting ability via a multiple trait selection.

scholarly journals Multiple Propagation Effects on Genetic Estimates of Rooting for Western Hemlock

1992 ◽  
Vol 117 (4) ◽  
pp. 651-655 ◽  
Author(s):  
Cecil T. Pounders ◽  
G. Sam Foster
Keyword(s):  
Root System ◽  
Genetic Gain ◽  
Clonal Selection ◽  
Western Hemlock ◽  
Clonal Variation ◽  
System Quality ◽  
Rooted Cuttings ◽  
Selection Procedures ◽  
Propagation Effects ◽  
Highly Correlated

Analysis of clonal variation for two rooting traits of western hemlock [Tsuga heteterophylla (Raf.) Sarg.] clones indicated that realized genetic gain would be improved by more effective partitioning and reduction of environmental differences associated with clones. Interactions between clones and multiple propagation dates were significant, but clone rank changes between dates were minor. Number of meted cuttings per plot (RC) and number of main roots per cutting (MR) were more highly correlated genetically (1.06) than phenotypically (0.36). Broad-sense heritabilitiesHx2 = 0.62 and Hx2 = 0.79 for RC and MR, respectively) and predicted genetic gain from clonal selection were moderately high. Both the percentage of rooted cuttings and root system quality could be rapidly improved by the clonal selection procedures used.

INHERITANCE OF FLOWERING TIME AND ITS APPLICATION FOR INDIRECT SELECTION IN THE DAVIS POPULATION OF GERBERA

HortScience ◽  
1990 ◽  
Vol 25 (11) ◽  
pp. 1357F-1358
Author(s):  
Yiran Yu ◽  
James Harding ◽  
Thomas Byrne
Keyword(s):  
Flowering Time ◽  
Genetic Correlations ◽  
Indirect Selection ◽  
Cut Flower ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Components Of Variance ◽  
Genetic Components ◽  
Flower Yield ◽  
Cut Flower Yield

Genetic components of variance and heritability of flowering time were estimated for five generations of the Davis Populationof Gerbera hybrids, Composite, Estimates of narrow-sense heritability averaged 0.50 and broad-sense heritability averaged 0.77 using the NCII design. Narrow-sense heritability was also estimated with two models of parent-offspring regression, resulting in average heritability of 0.49 and 0.51. Estimates of components of variance indicated that the major genetic effect controlling flowering time is additive. However, the dominance component accounted for 28% of the total variance; the environmental component was only 23%. Flowering time is negatively correlated with cut-flower yield. The phenotypic coefficient was –0.34; genetic correlations were –0.47 when estimated from the NCII design, and –0.72 when estimated from the parent-off-spring method. A practical model was constructed to assess the efficiency of indirect selection for cut-flower yield using flowering time as a marker trait. The advantages of indirect selection accruing from increased population size and reduced generation time are discussed.

The incorporation of fertility indices in genetic improvement programmes

2001 ◽  
Vol 26 (1) ◽  
pp. 237-249 ◽  
Author(s):  
J.E. Pryce ◽  
R.F. Veerkamp
Keyword(s):  
Genetic Variance ◽  
Selection Index ◽  
Genetic Correlations ◽  
Live Weight ◽  
Parameter Estimates ◽  
Phenotypic Variance ◽  
Production Traits ◽  
Genetic Progress ◽  
Detection Rates ◽  
Days Open

AbstractIn recent years there has been considerable genetic progress in milk production. Yet, increases in yield have been accompanied by an apparent lengthening of calving intervals, days open, days to first heat and a decline in conception rates, which appears to be both at the genetic and phenotypic level. Fertility has a high relative economic value compared to production traits such as protein, making it attractive to include in a breeding programme. To do this there needs to be genetic variance in fertility. Measures of fertility calculated from service dates have a small genetic compared to phenotypic variance, hence heritability estimates are small, typically less than 5%, although coefficients of genetic variance are comparable to those of production traits. Heritabilities of commencement of luteal activity determined using progesterone profiles are generally higher, and have been reported as being from 0.16 to 0.28, which could be because of a more precise quantification of genetic variance, as management influences such as delaying insemination and heat detection rates are excluded. However, it might not be the use of progesterone profiles alone, as days to first heat observed by farm staff has a heritability of 0.15. The most efficient way to breed for improved fertility is to construct a selection index using the genetic and phenotypic parameter estimates of all traits of interest in addition to their respective economic values. Index traits for fertility could include measures such as calving interval, days open, days to first service, or days to first heat but there may also be alternative measures. Examples include traits related to energy balance, such as live weight and condition score (change), both of which have higher heritabilities than fertility measures and have genetic correlations of sufficient magnitude to make genetic progress by using them feasible. To redress the balance between fertility and production, some countries already publish genetic evaluations of fertility including: Denmark, Finland, France, Germany, Israel, The Netherlands, Norway and Sweden.

scholarly journals Claw health and feed efficiency as new selection criteria in the Czech Holstein cattle Krupová Z., Wolfová M., Krupa E., Přibyl J., Zavadilová L.

2018 ◽  
Vol 63 (No. 10) ◽  
pp. 408-418 ◽  
Author(s):  
Z. Krupová ◽  
M. Wolfová ◽  
E. Krupa ◽  
J. Přibyl ◽  
L. Zavadilová
Keyword(s):  
Feed Intake ◽  
Feed Efficiency ◽  
Disease Incidence ◽  
Selection Index ◽  
Residual Feed Intake ◽  
Selection Response ◽  
Holstein Cattle ◽  
Breeding Objective ◽  
Economic Weights ◽  
The Impact

The objective of this study was to calculate economic weights for ten current breeding objective traits and for four new traits characterising claw health and feed efficiency in Czech Holstein cattle and to investigate the impact of different selection indices on the genetic responses for these traits. Economic weights were estimated using a bio-economic model, while applying actual (2017) and predicted (2025) production and economic circumstances. For the actual situation, the economic weights of claw disease incidence were –100.1 € per case, and those of daily residual feed intake in cows, breeding heifers, and fattened animals were –79.37, –37.16, and –6.33 €/kg dry matter intake per day, respectively. In the predicted situation, the marginal economic weights for claw disease and feed efficiency traits increased on average by 38% and 20%, respectively. The new traits, claw disease incidence and daily residual feed intake, were gradually added to the 17 current Holstein selection index traits to improve the new traits. Constructing a comprehensive index with 21 traits and applying the general principles of the selection index theory, a favourable annual genetic selection response was obtained for the new traits (–0.008 cases of claw disease incidence and –0.006 kg of daily residual feed intake across all cattle categories), keeping the annual selection response of the most important current breeding objective traits at a satisfactory level (e.g., 73 kg of milk yield per lactation, 0.016% of milk fat). Claw health and feed efficiency should be defined as new breeding objectives and new selection index traits of local dairy population.

scholarly journals Application of Nursery Testing in Long-Term White Spruce Improvement Programs

2007 ◽  
Vol 24 (4) ◽  
pp. 296-300 ◽  
Author(s):  
Yuhui Weng ◽  
Kathy Tosh ◽  
Yill Sung Park ◽  
Michele S. Fullarton
Keyword(s):  
Picea Glauca ◽  
Genetic Correlations ◽  
Field Tests ◽  
Field Performance ◽  
White Spruce ◽  
Height Growth ◽  
Positive Assortative Mating ◽  
The Family ◽  
Improvement Programs

Abstract Polycross-pollinated white spruce (Picea glauca [Moench] Voss) families were evaluated in field and retrospective nursery tests in 1989, 1991, and 1992, respectively. Height growth was measured at age 10 for the field tests and at ages 1 to 6 for the retrospective nursery tests. Except for a few cases, the family mean correlations between nursery and field heights were significant for the 1989 and 1992 series, and their corresponding genetic correlations ranged from low to medium (from 0.37 to 0.74). Because of heavy noncrop competition, height growth in the 1991 nursery series showed consistently lower heritabilities and correlations with field performance compared with those of the other two series. Early nursery selection by theoretical prediction was generally efficient for the 1989 and 1992 series. Rank classification analysis indicated that application of early nursery selection should be used with caution for identifying elite families but could be used to cull inferior families or clones, apply multiple-stage selection, or perform positive assortative mating.

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