Genetic parameters and correlations between stem size, forking, and flowering in teak (Tectona grandis)

2013 ◽  
Vol 43 (12) ◽  
pp. 1145-1150 ◽  
Author(s):  
Andrew N. Callister

The genetic improvement of teak (Tectona grandis Linn. f.), a high value tropical hardwood, has been hindered by a paucity of genetic parameter estimates. In particular, an association between flowering age and forking height has been suggested but never before quantified. In this study, 3- to 6-year data from a cloned progeny test were used to estimate heritability and genetic correlations among stem size, forking, and flowering traits. Mean narrow-sense heritability estimates [Formula: see text] were 0.09–0.10, and mean broad-sense heritability estimates ([Formula: see text]) were 0.38–0.45 for stem size traits. There were no age trends in [Formula: see text] or [Formula: see text]. Age–age additive and nonadditive genetic correlations were strong and were not related to the time interval between measurements. Forking height and forking age were under weak to moderate genetic control. Flowering age was under substantially greater genetic control, with [Formula: see text] of 0.21 and [Formula: see text] of 0.46. Additive and nonadditive genetic correlations between forking height and flowering age were estimated to be 0.84 and 0.55, respectively. Improvement of forking height was calculated to be almost twice as efficient by indirect selection on late flowering. These results suggest that within-provenance selection for teak stem size need not be delayed beyond 3 years and that indirect selection on flowering age will improve forking height.

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.


2021 ◽  
Vol 38 (1) ◽  
pp. 14-22
Author(s):  
M. Orunmuyi ◽  
I. A. Adeyinka ◽  
O.O Oni

A study was conducted to estimate the genetic parameters of fertility and hatchability in two strains of Rhode Island Red (RIR) Chickens denoted as Strain A and Strain B respectively using the full-sib (sire +dam variance) and maternal half-sib (dam variance) components. The birds were obtained from the selected populations of RIR Chickens kept at the poultry breeding programme of National Animal Production Research Institute, Shika, Zaria, Nigeria. Settable eggs were collected from mating 28 cocks to 252 hens in a ratio of 1cock:9 hens from each strain. Eggs were pedigreed according to sire and dam. Results showed that values obtained for number of egg set (EGGSET), number of fertile eggs (NFERT), number of hatched chicks (NHATCH), percentage of chicks hatched from total eggs set (PHATCH) and percentage of chicks hatched from fertile eggs (PHATCHBL) were all higher in strain A than strain B. Heritability estimates obtained from the full-sib and maternal half-sib analysis ranged from medium to high for the two strains (0.24-0.96). The maternal half sib estimates were higher (0.40-0.96) than the estimates obtained from full sibs (0.24- 0.48). Genetic and phenotypic correlations obtained for both strains were positive and similar regardless of method of estimation. Genetic correlations between EGGSET and PFERT were low in strain A using both full-sib and maternal half-sib analyses (0.09-0.14). Phenotypic correlations between EGGSET and PFERT, PHATCH and PHATCHBL were also low in both strains and regardless of method of analyses. Moderate to high heritability estimates suggest that genetic improvement can be obtained by selection of these reproductive traits. The full-sib analysis for estimating heritability will be preferred since it is assumed that only additive genetic variance contributes to the covariance between family members.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 21-22
Author(s):  
Lindsay R Upperman ◽  
Larry A Kuehn ◽  
Matthew L Spangler

Abstract The objective of this study was to estimate genetic parameters for days on feed (DOF), age at slaughter (AAS), and their relationships with carcass traits, including: marbling score (MARB), adjusted fat thickness (AFT), hot carcass weight (HCW), ribeye area (REA), and final live weight (FW). Data were from steers and heifers (n = 7,747) from the Germplasm Evaluation Program at the U.S. Meat Animal Research Center. All traits were analyzed with univariate and bivariate animal models using ASReml. Fixed effects fitted for all models included contemporary group (concatenation of birth year and season, sex, and experimental treatment group), breed fractions, and direct heterosis. Different endpoints were also investigated by fitting fixed linear covariates of AFT, HCW, REA, MARB, FW, and age (except AAS and DOF). For a given bivariate analyses, both traits were adjusted to the same endpoint. Univariate heritability estimates for AFT, AAS, DOF, FW, HCW, MARB, and REA ranged from 0.45–0.52, 0.52–0.59, 0.33–0.39, 0.34–0.55, 0.34–0.55, 0.54–0.55, and 0.50–0.56, respectively. Covariates of MARB and AFT led to the highest and lowest, respectively, heritability estimates for AAS and DOF. Depending on the endpoint, genetic correlations between AAS and AFT, FW, HCW, MARB, and REA ranged from 0.16 to 0.32, -0.08 to 0.33, 0.19 to 0.36, 0.14 to 0.20, and -0.06 to 0.13 (Table 1). Genetic correlations between DOF and AFT, MARB, and REA were negligible. Genetic correlations between DOF, FW, and HCW ranged from -0.10 to 0.29 and -0.37 to -0.17. Standard errors were less than 0.07 for all estimates. Phenotypic variability in DOF was low, and increased variability in AAS was due to differences in date of birth and thus weaning age. Results indicate DOF and AAS are moderately to highly heritable and generally lowly correlated with routine carcass traits. The USDA is an equal opportunity employer.


2004 ◽  
Vol 34 (12) ◽  
pp. 2601-2610 ◽  
Author(s):  
Satish Kumar

Data from two separate experiments were used to estimate genetic parameters for different wood properties of Pinus radiata D. Don in New Zealand. In experiment 1, 72 and 60 open-pollinated families were sampled at two sites, Kinleith and Paengaroa, respectively. Fifty-nine such families were common to both sites. In experiment 2, 62 and 29 pollen-parent families were sampled from a female-tester trial at two sites, Kaingaroa and Warrengong (the latter in Australia), respectively. Twenty-nine such families were common to both sites. Clearwood stiffness (MOE) and strength (MOR), wood density (DEN), acoustic stiffness on standing trees (IMLH), acoustic stiffness in 5-m logs (HITMAN), external resin bleeding (ERB), internal checking from discs taken at 1.3-m and 3.0-m height (CHEK_B and CHEK_U), and diameter at breast height (DBH) were assessed. Within-site narrow-sense heritability (h2) estimates of various wood properties were consistent, particularly within New Zealand. Across-sites estimates of h2 of HITMAN, CHEK_B, and DEN were, respectively, 0.24, 0.40, and 0.62 in experiment 1 and 0.21, 0.16, and 0.38 in experiment 2. Estimated type B genetic correlations were generally high for all traits except DBH. DEN showed strong positive genetic correlation with all direct and acoustic measures of stiffness (MOE, HITMAN, and IMLH). DEN and all measures of stiffness showed low to moderate negative genetic correlations with DBH.


2013 ◽  
Vol 25 (5) ◽  
pp. 775 ◽  
Author(s):  
M. E. Buzanskas ◽  
R. P. Savegnago ◽  
D. A. Grossi ◽  
G. C. Venturini ◽  
S. A. Queiroz ◽  
...  

Phenotypic data from female Canchim beef cattle were used to obtain estimates of genetic parameters for reproduction and growth traits using a linear animal mixed model. In addition, relationships among animal estimated breeding values (EBVs) for these traits were explored using principal component analysis. The traits studied in female Canchim cattle were age at first calving (AFC), age at second calving (ASC), calving interval (CI), and bodyweight at 420 days of age (BW420). The heritability estimates for AFC, ASC, CI and BW420 were 0.03 ± 0.01, 0.07 ± 0.01, 0.06 ± 0.02, and 0.24 ± 0.02, respectively. The genetic correlations for AFC with ASC, AFC with CI, AFC with BW420, ASC with CI, ASC with BW420, and CI with BW420 were 0.87 ± 0.07, 0.23 ± 0.02, –0.15 ± 0.01, 0.67 ± 0.13, –0.07 ± 0.13, and 0.02 ± 0.14, respectively. Standardised EBVs for AFC, ASC and CI exhibited a high association with the first principal component, whereas the standardised EBV for BW420 was closely associated with the second principal component. The heritability estimates for AFC, ASC and CI suggest that these traits would respond slowly to selection. However, selection response could be enhanced by constructing selection indices based on the principal components.


HortScience ◽  
1990 ◽  
Vol 25 (11) ◽  
pp. 1357F-1358
Author(s):  
Yiran Yu ◽  
James Harding ◽  
Thomas Byrne

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.


2010 ◽  
Vol 40 (5) ◽  
pp. 917-927 ◽  
Author(s):  
Desmond J. Stackpole ◽  
René E. Vaillancourt ◽  
Geoffrey M. Downes ◽  
Christopher E. Harwood ◽  
Brad M. Potts

Pulp yield is an important breeding objective for Eucalyptus globulus Labill., but evaluation of its genetic control and genetic correlations with other traits has been limited by its high assessment cost. We used near infrared spectroscopy to study genetic variation in pulp yield and other traits in a 16-year-old E. globulus trial. Pulp yield was predicted for 2165 trees from 467 open-pollinated families from 17 geographic subraces. Significant differences between subraces and between families within subraces were detected for all traits. The high pulp yield of southern Tasmanian subraces suggested that their economic worth was previously underestimated. The narrow-sense heritability of pulp yield was medium (0.40). The significant positive genetic correlation between pulp yield and diameter (0.52) was at odds with the generally neutral values reported. The average of the reported genetic correlations between pulp yield and basic density (0.50) was also at odds with our nonsignificant estimate. Pulp yield of the subraces increased with increasing latitude, producing a negative correlation with density (–0.58). The absence of genetic correlations within subraces between pulp yield and density suggests that the correlation may be an independent response of the two traits to the same or different selection gradients that vary with latitude.


2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 158-159
Author(s):  
Chad A Russell ◽  
E J Pollak ◽  
Matthew L Spangler

Abstract The commercial beef cattle industry relies heavily on the use of natural service sires. Either due to the size of breeding herds or to safe-guard against injury during the breeding season, multiple-sire breeding pastures are utilized. Although each bull might be given an equal opportunity to produce offspring, evidence suggest that there is substantial variation in the number of calves sired by each bull in a breeding pasture. DNA-based paternity assignment enables correct assignment of calves to their respective sires in multi-sire pastures and presents an opportunity to investigate the degree to which this trait complex is under genetic control. Field data from a large commercial ranch were used to estimate genetic parameters for calf count (CC; n=623) and yearling scrotal circumference (SC; n=1962) using univariate and bivariate animal models. Average CC and SC were 12.1±11.1 calves and 35.4±2.30 cm, respectively. Average number breeding seasons per bull and bulls per contemporary group were 1.40 and 24.9, respectively. The model for CC included fixed effects of age during the breeding season (in years) and contemporary group (concatenation of breeding pasture and year). Random effects included additive genetic and permanent environmental effects, and a residual. The model for SC included fixed effects of age (in days) and contemporary group (concatenation of month and year of measurement). Random effects included an additive genetic effect and a residual. Univariate model heritability estimates for CC and SC were 0.237±0.156 and 0.456±0.072, respectively. Similarly, the bivariate model resulted in heritability estimates for CC and SC of 0.240±0.155 and 0.461±0.072, respectively. Repeatability estimates for CC from univariate and bivariate models were 0.517±0.054 and 0.518±0.053, respectively. The estimate of genetic correlation between CC and SC was 0.270±0.220. Parameter estimates suggest that both CC and SC would respond favorably to selection and that CC is moderately repeatable.


1977 ◽  
Vol 57 (3) ◽  
pp. 383-388 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY

A total of 13,561 Holstein 305-day lactation records from 779 Quebec and Maritime herds enrolled on the Dairy Herd Analysis Service were used to evaluate the importance of sire × herd interactions for milk yield and composition traits. Sire × herd interaction accounted for 4.1, 1.1, 0.3, 2.6 and 5.6% of the total variation of milk, fat and protein yield and fat and protein percent, respectively. Genetic parameter estimates obtained under two different models, a full model that accounted for sire × herd interaction and a reduced model that ignored it, were examined. Heritabilities of milk, fat and protein yield and fat and protein percent were, respectively: for the full model, 0.36, 0.47, 0.45, 0.59 and 0.31 and for the reduced model, 0.49, 0.50, 0.46, 0.66 and 0.46. Phenotypic correlations between the traits were not appreciably different when estimated under the full and reduced models. Genetic correlations between the yield traits were also similar when estimated under the full and reduced models, but genetic correlations between yield and percentage traits were more stongly positive, or less negative, when sire × herd interaction was accounted for. The genetic correlation between fat and protein percent was larger under the reduced model than under the full model.


1994 ◽  
Vol 24 (7) ◽  
pp. 1480-1486 ◽  
Author(s):  
R.J. Arnold ◽  
J.B. Jett ◽  
S.E. McKeand

Open-pollinated progeny trials of Fraser fir (Abiesfraseri (Pursh) Poir.) assessed at 8 years provided genetic parameter estimates for growth, Christmas tree quality traits, and wholesale value at harvest age. Significant variation was found between and within nine different seed sources. Estimated individual tree heritabilities of important traits ranged from a low of 0.13 for USDA Christmas tree grade to a moderate value of 0.33 for crown diameter. Heritabilities within the better performing seed sources tended to be higher. Of the two traits that determine wholesale value, USDA grade and height class, the latter proved to have the greater influence, both phenotypically and genetically. Genetic correlations of early age height growth with 8-year total height, height class, USDA Christmas tree grade, and individual tree wholesale value proved favorable and strong (range of 0.57–0.96). In combination with moderate heritabilities for early growth traits, such correlations provide potential for effective early age selections in Fraser fir Christmas trees.


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