scholarly journals Estimates of genetic parameters and genetic gains for growth traits of twoEucalyptus urophyllapopulations in Zululand, South Africa

2016 ◽  
Vol 78 (3) ◽  
pp. 209-216 ◽  
Author(s):  
Gert J van den Berg ◽  
Steven D Verryn ◽  
Paxie W Chirwa ◽  
Francois van Deventer
Keyword(s):  
South Africa ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Gains

scholarly journals Genetic Evaluation and Combined Selection for the Simultaneous Improvement of Growth and Wood Properties in Catalpa bungei Clones

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 868
Author(s):  
Yao Xiao ◽  
Junhui Wang ◽  
Huiling Yun ◽  
Guijuan Yang ◽  
Jianwei Ma ◽  
...  
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Wood Quality ◽  
Basic Density ◽  
Wood Properties ◽  
Dry Density ◽  
Genetic Gains ◽  
Catalpa Bungei ◽  
Combined Selection

Catalpa bungei is an important timber tree. Improvements in growth and wood quality are important goals of C. bungei breeding, and it is necessary to understand the genetic parameters of specific target traits and genetic correlation between growth traits and wood properties for tree breeding. In this study, the genetic parameters of height, diameter at breast height (DBH) and wood properties were estimated and genetic and phenotypic correlations between growth traits and wood properties were evaluated in C. bungei. Finally, different selection scenarios were used to evaluate and select optimal clones. The results showed that there were significant differences in growth and wood properties among clones. The wood hardness (0.66–0.79), basic density (0.89), air-dried density (0.89) and compression strength parallel to the grain of wood (CSP) (0.84) had high repeatability. The variance component proportions indicated that the variation in wood properties came mainly from different genotypes (clones) rather than from different individuals of the same clone. The DBH showed a significant negative genetic correlation with the hardness of radial section (HRS) (−643), basic density (−0.531) and air-dry density (−0.495). This unfavorable relationship makes it difficult to improve growth and wood quality simultaneously in C. bungei. We selected the optimal clones under different scenarios, and we obtained 7.75–9.06% genetic gains for growth in the scenario in which height and DBH were the target traits. Genetic gains of 7.43–14.94% were obtained for wood properties by selecting optimal clones in the scenario in which wood properties were the target traits. Approximately 5% and 4% genetic gains were obtained for growth and wood properties, respectively, for the combined selection. This study provides new insights into the genetic improvement of wood quality in C. bungei.

Evaluation of Bonsmara and Belmont Red cattle breeds in South Africa. 2. Genetic parameters for growth and fertility

2006 ◽  
Vol 46 (2) ◽  
pp. 213 ◽  
Author(s):  
N. J. Corbet ◽  
R. K. Shepherd ◽  
H. M. Burrow ◽  
K. C. Prayaga ◽  
J. van der Westhuizen ◽  
...  
Keyword(s):  
South Africa ◽  
Maternal Effects ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Repeated Measurements ◽  
Maternal Influence ◽  
Parameter Estimates ◽  
Fertility Traits

Genetic parameters were estimated for growth and fertility indicator traits in a South African beef cattle population. Measurements on 5601 pedigreed progeny of 96 Bonsmara sires, 18 Belmont Red sires and 20 Bonsmara × Belmont Red cross sires were recorded over 19 years in 4 diverse climatic regions of South Africa. Growth traits were measured on growing stock from birth to 18 months at pasture. Cow weights were measured at calving and weaning. Age at first calving, and repeated measurements of calving day and calving interval were recorded on 1993 breeding females as indicators of reproductive performance. The traits were analysed using univariate and bivariate animal models with maternal effects fitted. Direct heritability of growth traits (0.11–0.42) and female fertility traits (0.02–0.13) suggested that genetic progress could be made by selection for some traits. Genetic correlations between growth and fertility traits were variable (–0.47–0.85) and indicated that multi-trait selection would be the best method of dealing with multidirectional forces on productivity traits. Genetic correlations between direct and maternal effects on liveweight traits were mostly negative indicating that genetic improvement of traits with strong maternal influence, such as weaning weight, would be complicated and supported the use of post-weaning weights with less maternal influence as selection criteria to improve the direct additive component of growth. The genetic parameter estimates provide useful reference values for estimation of breeding values in a proposed combined-breed genetic evaluation program.

scholarly journals Estimates of (co)variance components and genetic parameters of growth traits in Marwari sheep

2014 ◽  
Vol 44 (1) ◽  
pp. 27-35 ◽  
Author(s):  
H. Singh ◽  
U. Pannu ◽  
H.K. Narula ◽  
A. Chopra ◽  
V. Naharwara ◽  
...  
Keyword(s):  
Variance Components ◽  
Genetic Parameters ◽  
Growth Traits

scholarly journals Adaptability, stability, productivity and genetic parameters in slash pine second-generation families in early age

2016 ◽  
Vol 65 (1) ◽  
pp. 71-82 ◽  
Author(s):  
M.K. Pagliarini ◽  
W.S. Kieras ◽  
J.P. Moreira ◽  
V.A. Sousa ◽  
J.Y. Shimizu ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genetic Parameters ◽  
Second Generation ◽  
Growth Traits ◽  
Environmental Influence ◽  
Block Design ◽  
Slash Pine ◽  
Phenotypic Traits ◽  
Early Age ◽  
Wood Volume

AbstractThe study was conducted to estimate the stability, adaptability, productivity and genetic parameters in Slash pine second-generation half-sib families, considering phenotypic traits in early age. Forty-four families from a first generation seed orchard in Colombo-PR, Brazil, were used in this study. Two progenies tests were established in a randomized complete block design. The first test was implemented in March 2009 in Ribeirão Branco, São Paulo state, containing 40 blocks, one tree per plot, 44 treatments (progenies) and 6 controls. Another test was implemented in Ponta Grossa, Paraná state, using the same experimental design and number of plants per plot, and with 24 treatments, 32 blocks. The growth traits evaluated were total height, diameter at breast height (dbh) and wood volume, within five years. The form traits evaluated were stem form, branch thickness, branch angle, number of branches, fork and fox tail five years after planting. Deviance analysis and estimates of stability, adaptability, productivity and genetic parameters were performed using the methods of best linear unbiased predictor (BLUP) and residual maximum likelihood (REML). There was significant variation among progenies for growth and form traits. Considerable genetic variation was detected mainly for wood volume. High coefficients of genetic variation and heritability showed low environmental influence on phenotypic variation, which is important for the prediction of genetic gain by selection. Crosses between different progenies individuals groups will be prioritized for obtaining heterotics genotypes and increase the probability of obtaining high specific combining ability.

scholarly journals Estimates of genetic gains for growth traits in young plants of Eucalyptus urophylla S. T. Blake

CERNE ◽  
2011 ◽  
Vol 17 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Thais Galhardo Godoy ◽  
Sebastião Carlos da Silva Rosado
Keyword(s):  
Quality Index ◽  
Dry Matter ◽  
Growth Traits ◽  
Block Design ◽  
Genetic Gains ◽  
Random Block ◽  
Collar Diameter ◽  
Random Block Design ◽  
Root Collar ◽  
Dickson Quality Index

The objective of this study was the selection of superior genotypes for growth traits, correlating them to initial height growth in the field, at age eight months. A random block design was used in the nursery, with eight clones, three replicates and four plants per plot. And a random block design was also used in the field, with eight clones, four replicate blocks and nine plants per plot. Data being analyzed in the nursery at age 120 days included: height of field seedling, at age eight months (Hc), height of nursery seedling (Hm), root collar diameter (Dc), shoot diameter (Db), shoot dry matter (PMSPA), root dry matter (PMSR), total dry matter (PMST), ratio of shoot dry matter to root dry matter (PMSPA/PMSR), Dickson quality index of root collar diameter (IQD-Dc), Dickson quality index of shoot diameter (IQD-Db). Analyses of variance showed that significant genetic differences exist among clones for all traits and, given the high heritability values found, the estimated genetic gains were generically very high. As for predicted indirect genetic gain, selection in nursery seedlings for Dc, PMSPA/PMSR, IQD-Dc provided the highest values of indirect gain in field seedling height.

Application of multivariate heavy-tailed distributions to residuals in the estimation of genetic parameters of growth traits in beef cattle1

2013 ◽  
Vol 91 (4) ◽  
pp. 1552-1561 ◽  
Author(s):  
S. O. Peters ◽  
K. Kizilkaya ◽  
D. J. Garrick ◽  
R. L. Fernando ◽  
E. J. Pollak ◽  
...  
Keyword(s):  
Genetic Parameters ◽  
Growth Traits ◽  
Heavy Tailed Distributions ◽  
Heavy Tailed ◽  
Estimation Of Genetic Parameters

scholarly journals Genetic parameters and estimated genetic gains in young rubber tree progenies

2013 ◽  
Vol 48 (4) ◽  
pp. 411-416 ◽  
Author(s):  
Cecília Khusala Verardi ◽  
Erivaldo José Scaloppi Junior ◽  
Guilherme Augusto Peres Silva ◽  
Lígia Regina Lima Gouvêa ◽  
Paulo de Souza Gonçalves
Keyword(s):  
Genetic Gain ◽  
Genetic Parameters ◽  
Block Design ◽  
Rubber Tree ◽  
First Year ◽  
Genetic Gains ◽  
Selection Gain ◽  
Randomized Block Design ◽  
Using Data ◽  
Selection Of

The objective of this work was to assess the genetic parameters and to estimate genetic gains in young rubber tree progenies. The experiments were carried out during three years, in a randomized block design, with six replicates and ten plants per plot, in three representative Hevea crop regions of the state of São Paulo, Brazil. Twenty-two progenies were evaluated, from three to five years old, for rubber yield and annual girth growth. Genetic gain was estimated with the multi-effect index (MEI). Selection by progenies means provided greater estimated genetic gain than selection based on individuals, since heritability values of progeny means were greater than the ones of individual heritability, for both evaluated variables, in all the assessment years. The selection of the three best progenies for rubber yield provided a selection gain of 1.28 g per plant. The genetic gains estimated with MEI using data from early assessments (from 3 to 5-year-old) were generally high for annual girth growth and rubber yield. The high genetic gains for annual girth growth in the first year of assessment indicate that progenies can be selected at the beginning of the breeding program. Population effective size was consistent with the three progenies selected, showing that they were not related and that the population genetic variability is ensured. Early selection with the genetic gains estimated by MEI can be made on rubber tree progenies.

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