Genetic variability for girth growth and rubber yield in Hevea brasiliensis

Basic knowledge of genetic characteristics of populations is necessary to conduct effective breeding and selection. The objective of this paper is describing the genetic variation of rubber yield and the correlation with other traits, and estimating the genetic parameters for girth growth and total number of latex vessels. Sixty seven clones of Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg. were tested at five sites during 10 years. Characters girth growth at panel opening and rubber yield, showed broad sense heritability on plot mean level, from 0.32 to 0.66 and 0.59 to 0.92, respectively. Predicted genetic gains equal to 0.73 cm and 0.79 g increase respectively on girth and yield in the opening panel and mature phases seems realistic, even with moderate selection intensities. Genetic correlations with rubber yield, bark thickness and total number of latex vessels were very large, and almost no genotype-environment interaction was present for girth growth. High genotype-environment interaction was present for rubber yield with genetic and phenotypic correlations across the sites, ranging from 0.64 to 0.92 (genetic) and 0.63 to 0.89 (phenotypic). Total number of latex vessels rings had a high heritability, ranging from 20.0% to 64.0% in the sites E and B, respectively.

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Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽

10.1093/genetics/143.3.1409 ◽

1996 ◽

Vol 143 (3) ◽

pp. 1409-1416 ◽

Cited By ~ 1

Author(s):

Kenneth R Koots ◽

John P Gibson

Keyword(s):

Genetic Correlation ◽

Genetic Parameters ◽

Genetic Parameter ◽

Genetic Correlations ◽

Phenotypic Correlation ◽

Parameter Estimates ◽

Sampling Variance ◽

Phenotypic Correlations ◽

Genetic And Phenotypic Correlations ◽

Heritability Estimates

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.

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Genetic parameters of Barki sheep raised under semi-arid conditions

Animal Science ◽

10.1017/s0003356100027008 ◽

1969 ◽

Vol 11 (3) ◽

pp. 361-367 ◽

Cited By ~ 9

Author(s):

M. H. Fahmy ◽

E. Salah E. Galal ◽

Y. S. Ghanem ◽

S. S. Khishin

Keyword(s):

Genetic Parameters ◽

Genetic Correlations ◽

Research Station ◽

Phenotypic Correlations ◽

Arid Conditions ◽

Body Weights ◽

Genetic And Phenotypic Correlations ◽

Fleece Weight ◽

Semi Arid ◽

Desert Research

SUMMARYRecords on 695 lambs were collected over a period of 5 years from 1961/62 to 1965/66, at Ras El-Hekma Desert Research Station, 230 km west of Alexandria. The characters studied were birth, weaning and yearling body weights, pre- and post-weaning daily gains and greasy fleece weight.Birth, 120-day and 365-day body weights were 3·4, 18·2 and 33·4 kg respectively. Greasy fleece weight at 16 months of age was 3·29 kg. Heritability estimates of birth, weaning, yearling weights, pre- and post-weaning daily gains and greasy fleece weight were 0·22, 0·45, 0·41,0·45 and 0·29 respectively. Genetic and phenotypic correlations between birth, weaning and yearling weights were all positive and significant. Genetic correlations between fleece weight and body characteristics were negative and low.

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Genetic parameters and genotype–environment interactions of Chinese fir (Cunninghamia lanceolata) in Fujian Province

Canadian Journal of Forest Research ◽

10.1139/cjfr-2013-0427 ◽

2014 ◽

Vol 44 (6) ◽

pp. 582-592 ◽

Cited By ~ 14

Author(s):

Liming Bian ◽

Jisen Shi ◽

Renhua Zheng ◽

Jinhui Chen ◽

Harry X. Wu

Keyword(s):

Genetic Parameters ◽

Breeding Strategy ◽

Chinese Fir ◽

Breeding Program ◽

Cunninghamia Lanceolata ◽

Environment Interaction ◽

Fujian Province ◽

The Third ◽

Genotype Environment Interaction ◽

Sib Families

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is the most commercially important conifer in China, and the Nanjing Forestry University – Fujian Province Chinese fir Cooperation (NJFU – Fujian Cooperation) breeding program has advanced it into the third cycle of selection and breeding. In this paper, we estimated genetic parameters from four sites for 80 half-sib families and summarized previous estimates of genetic parameters in Chinese fir with an objective to propose optimal breeding strategy. Heritability averaged 0.20 and 0.14 for height and diameter at breast height (DBH), respectively, for the four sites. A significant genotype–environment interaction (G × E) for growth was also observed among the four sites, with the greatest interactions between a marginal site and the three central sites in the Fujian Province Chinese fir plantation region. The average estimated type-B genetic correlation between the marginal site and the three central sites was 0.08 for height and –0.09 for DBH. However, the highly productive families were among the most stable across the four sites. The results from this study in combination with summarized genetic parameters from literature were used to discuss and propose an optimal breeding strategy for the third generation of the breeding program for Chinese firs in Fujian Province.

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Genetic parameters of production and reproduetive traits in on a farm tested Danish Large White and Landrace swine in Greece

Archives Animal Breeding ◽

10.5194/aab-43-287-2000 ◽

2000 ◽

Vol 43 (3) ◽

pp. 287-298

Author(s):

J. Bizelis ◽

A. Kominakis ◽

E. Rogdakis ◽

F. Georgadopoulou

Keyword(s):

Maximum Likelihood ◽

Genetic Correlation ◽

Genetic Parameters ◽

Genetic Correlations ◽

Production Traits ◽

Likelihood Methods ◽

Large White ◽

Reproduction Traits ◽

Maximum Likelihood Methods ◽

Genetic And Phenotypic Correlations

Abstract. Production and reproduetive traits in Danish Landrace (LD) and Large White (LW) swine were analysed by restricted maximum likelihood methods to obtain heritabilities as well as genetic and phenotypic correlations. Production traits were: age, backfat thickness (BT), muscle depth (MD) and the ratio BT/MD, adjusted to Standard bodyweight of 85 kg. Reproduction traits were: number of pigs born (NB) and number of pigs weaned (NW) per sow and parity. Heritabilities for age, BT, MD and BT/MD were 0.60, 0.44, 0.51 and 0.42 for LD and 0.36, 0.44, 0.37 and 0.45 for LW, respectively. Genetic correlations between age and BT were −0.22 in LD and – 0.44 in LW. The genetic correlation between age and MD was close to zero in both breeds. Genetic correlation between BT and MD were −0.36 and −0.25 in LD and LW, respectively. Heritabilities for NB were 0.25 in LD and 0.13 in LW while heritabilities for NW were close to zero in both breeds. Genetic correlation between NB and NW was 0.46 and 0.70 in LD and LW, respectively.

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In silico investigation of the effect of nutrition on the estimates of genetic parameters for lambs infected with gastro-intestinal parasites

Proceedings of the British Society of Animal Science ◽

10.1017/s175275620001992x ◽

2007 ◽

Vol 2007 ◽

pp. 89-89

Author(s):

A. B. Doeschl-Wilson ◽

D. Vagenas ◽

S.C. Bishop ◽

I. Kyriazakis

Keyword(s):

Dietary Protein ◽

Genetic Parameters ◽

Intestinal Parasites ◽

Protein Supplementation ◽

Gastrointestinal Parasites ◽

Environment Interaction ◽

Phenotypic Correlations ◽

Nutritional Conditions ◽

Breeding Programmes ◽

Genetic And Phenotypic Correlations

In recent years there has been an increased interest for breeding lambs resistant to gastrointestinal parasites due to the reduced efficacy of anthelminthics. Furthermore, protein supplementation alleviates the adverse effects of parasitism since more protein is available for the satisfaction of the competing body functions of growth and resistance to parasites. Therefore, differences in dietary protein might result in the expression of genotype x environment interaction. Additionally the estimates of genetic and phenotypic correlations obtained from populations kept under different nutritional conditions might differ with implications for the breeding programmes. The aim here is to explore the effect of dietary protein level on the estimates of genetic and phenotypic correlations of a population of growing lambs infected with gastrointestinal parasites using a simulation model.

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Adaptation of field pea varieties to organic farming across different environments of Italy

Crop and Pasture Science ◽

10.1071/cp18216 ◽

2019 ◽

Vol 70 (4) ◽

pp. 327 ◽

Cited By ~ 3

Author(s):

Luciano Pecetti ◽

Angelo R. Marcotrigiano ◽

Luigi Russi ◽

Massimo Romani ◽

Paolo Annicchiarico

Keyword(s):

Grain Yield ◽

Southern Italy ◽

Ascochyta Blight ◽

Genetic Correlations ◽

Field Pea ◽

Environment Interaction ◽

Adaptive Responses ◽

Climatic Regions ◽

Organic Systems ◽

Genotype Environment Interaction

This study aimed to support field pea (Pisum sativum L.) breeding strategies for organic systems of southern European environments, by assessing the size of genotype × environment interaction (GEI) due to spatial and temporal factors across climatically contrasting regions and identifying plant characters associated with genotype adaptive responses. Twelve recent varieties were evaluated for grain yield and other traits in six organically managed environments (three sites × two cropping years) of northern, central and southern Italy. GEI for grain yield was large, with the variety × site × year interaction greatly exceeding the variety × site interaction. This finding, and the similar magnitude of the mean genetic correlations for variety yields across pairs of sites (rg = 0.56) and pairs of years (rg = 0.51), indicated the difficulty of exploiting variety × site interaction effects by breeding for specific climatic regions. Pattern analysis highlighted the large inconsistency across years for GEI pattern of the sites from central and southern Italy. GEI also complicated the targeting of varieties, owing to inconsistent top-performing material across years according to additive main effects and multiplicative interaction (AMMI)-modelled yields. Higher genotype mean yield was strictly associated (P < 0.01) with lower weed proportion (hence, greater competitiveness against weeds: r = –0.96), taller plants (r = 0.89) and larger seeds (r = 0.78), with looser associations with lower susceptibility to lodging and ascochyta blight. These traits, which also contributed to preferential adaptation to the moisture-favourable environments of northern Italy, could be selected in breeding widely adapted varieties.

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Genotype-environment interaction, genetic trends, and performance dissimilarity of Nellore herds raised in three different environmental gradients

Semina Ciências Agrárias ◽

10.5433/1679-0359.2018v39n1p349 ◽

2018 ◽

Vol 39 (1) ◽

pp. 349

Author(s):

Julio Cesar de Souza ◽

Fabio Rafael Leão Fialho ◽

Marcos Paulo Gonçalves Rezende ◽

Carlos Henrique Cavallari Machado ◽

Mariana Pereira Alencar ◽

...

Keyword(s):

Weight Gain ◽

Fixed Effects ◽

Genetic Parameters ◽

Environmental Gradients ◽

Superior Performance ◽

Environment Interaction ◽

Genotype Environment Interaction ◽

And Performance ◽

Main Components ◽

Genetic Trends

The objectives of this work were to evaluate the genotype-environment interaction, and estimate genetic parameters, genetic trends, and performance dissimilarity-weight gain from birth to weaning (WGBW), adjusted weight to 205 days (W205), weight gain from weaning to 18 months of age (WG18), and adjusted weight to 550 days (W550)-in Nellore animals born between 1986 and 2012, and raised in pasture-based system in three different environmental gradients in Brazil. Data of 62,001 animals-11,729 raised in the Alto Taquari/Bolsão region (ATBR), 21,143 raised in the Campo Grande/Dourados region (CGDR) and 29,129 raised in the western São Paulo/Paraná region (SPPR) in Brazil-were used. The contemporary groups were defined by sex, location, and birth year and season, with at least nine individuals, two different environments, and breeding bulls with at least five progenies. The statistical model contained the direct additive and residual genetic effects (random effects), and environmental and contemporary group effects (fixed effects). Genetic parameters, genotype-environment interaction and genetic trends were estimates using animal model (uni- and/or bi- traits). The level of similarity between regions was evaluated using principal components. The animals raised in the CGDR had superior performance regarding the traits evaluated. The direct heritability estimates ranged from 0.39 to 0.44 (WGBW), 0.41 to 0.45 (W205), 0.42 to 0.55 (WG18) and 0.60 to 0.62 (W550). The maternal heritability of the traits ranged from 0.20 (WGBW), 0.12 to 0.18 (W205), 0.00 to 0.06 (WG18) and 0.02 to 0.22 (W550). According to the Spearman correlation, the ranking of the breeding bulls in the regions evaluated were different. The mean of Euclidean distance indicated low similarity between ATBR and CGDR (43.20), and ATBR and SPPR (29.24). CGDR and SPPR presented similarity of 17.84. The breed values increased over the years in the traits evaluated. The cumulative variance percentage of the first two main components explained 99.99% variation among the regions, and the weight gains of the animals were the most important to differentiate the regions. A genotype-environment interaction was found for the traits evaluated, thus, the breeding bull selected with superior genetic merit for one region might not be the best for others.

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EFFECT OF FIXED FACTORS AND ESTIMATION OF GENETIC PARAMETERS OF GROWTH TRAITS FOR MOUNTAIN KIDS

IRAQI JOURNAL OF AGRICULTURAL SCIENCES ◽

10.36103/ijas.v50i6.843 ◽

2019 ◽

Vol 50 (6) ◽

Author(s):

Hermiz & Baper

Keyword(s):

Variance Components ◽

Fixed Effects ◽

Genetic Parameters ◽

Maximum Likelihood Method ◽

Growth Traits ◽

Genetic Correlations ◽

Likelihood Method ◽

Phenotypic Correlations ◽

Body Weights ◽

Genetic And Phenotypic Correlations

Body weights at birth (469), weaning (394) and at six month of age (358) for kids utilized in this study were raised at private project in Duhok governorate, Iraq during two kidding season (2016-2017) and (2017-2018). GLM within SAS programme was used to analyze the data which include the fixed effects (age of doe, year and season of kidding, sex of kid and type of birth, regression on doe weight at kidding, and the regression of later weights of kids on earlier weights) influencing the studied traits. Restricted Maximum Likelihood Method was used to estimate repeatability, heritability, genetic and phenotypic correlations after adjusting the records for fixed effects. Variance components of random effects were tested for positive definite. Overall mean of weights at birth (BWT), weaning (WWT) and 6 month of age (WT6M) were 2.92, 15.32 and 24.45 kg, respectively. Differences among groups of age of doe in all studied traits were not significant, while year of kidding and sex of kid affect all traits significantly (p<0.01). Season of kidding affect BWT and WWT significantly (P<0.01). Single born kids were heavier (P<0.01) than twins in BWT only. Regression of BWT on doe weight at kidding (0.033 kg/kg) was significant (P<0.01), while the regressions of WWT and WT6M were not significant. The regression coefficients of WWT on BWT (1.906 kg/kg) and of WT6M on WWT (0.835 kg/kg) were highly significant (P<0.01). Repeatability estimates for BWT, WWT and WT6M were 0.47, 0.45 and 0.35, respectively; on the same order the estimates of heritability were 0.41, 0.61 and 0.79. Genetic correlations between BWT with each of WWT (0.45) and WT6M (0.55), and between WWT and WT6M (0.68) were highly significant. All phenotypic correlations between each pair of body weights were higher than genetic correlations and ranged between 0.48 and 0.73.

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AN EXPERIMENTAL EVALUATION OF GENETIC CORRELATION

Genetics ◽

10.1093/genetics/75.4.709 ◽

1973 ◽

Vol 75 (4) ◽

pp. 709-726

Author(s):

J J Rutledge ◽

E J Eisen ◽

J E Legates

Keyword(s):

Body Weight ◽

Genetic Correlation ◽

Genetic Parameters ◽

Genetic Correlations ◽

Tail Length ◽

Current Theory ◽

Standard Errors ◽

Index Selection ◽

Effective Population ◽

Selection Intensities

ABSTRACT Heritability and genetic correlations realized from both single-trait and antagonistic index selection were compared with paternal half-sib estimates. Primary attention was focused on the genetic correlation between six-week body weight and six-week tail length. Parameters realized from single-trait selection were in excellent agreement with paternal half-sib estimates. However, the realized genetic correlation between six-week body weight and six-week tail length obtained from index selection was significantly greater than the other estimates. Differential inbreeding levels and realized selection intensities were considered and rejected as being causative factors for these results. Linkage disequilibrium probably was not a factor either, as the base population had been randomly mated and randomly selected with a large effective population size for many generations. It was concluded that with antagonistic index selection, the pleiotropic effects of genes may be more powerful in retarding response in aggregate genotype than current theory would suggest. Replication of all selected and control lines allowed the use of between-line estimators of sampling variances of realized genetic parameters in the above comparisons. Generally, standard errors of realized genetic parameters were much smaller than corresponding paternal half-sib standard errors. Thus, selection was an efficient method of estimation.

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Genetic parameter estimates for important traits on the fifth generation in red tilapia in Vietnam

The Journal of Agriculture and Development ◽

10.52997/jad.7.01.2021 ◽

2021 ◽

Vol 20 (1) ◽

pp. 49-57

Author(s):

Sang V. Nguyen

Keyword(s):

Body Weight ◽

Survival Rate ◽

Genetic Parameters ◽

Genetic Parameter ◽

Genetic Correlations ◽

Parameter Estimates ◽

Environment Interaction ◽

Body Colour ◽

Red Tilapia ◽

Gxe Interaction

Genetic parameters comprising heritability, genetic correlation and genotype by environment interaction (GxE) for growth survival rate and body colour at harvest were estimated on the 5th selective generation of red tilapia grown in two environments, freshwater and brackishwater ponds. A total of 116 full-half-sib families was produced as well as 4,432 and 3,811 tagged individuals were tested in freshwater and brackishwater ponds, respectively. Genetic parameters were estimated by ASReml 4.1 software. The heritability for body weight and survival rate was high while medium heritability for body colour in freshwater was observed. The heritability for those traits of red tilapia in brackishwater. Together with the figures in earlier publication on previous generations (G1 to G4) in the same selective population, the expected medium to high response acquires if selection is done for each trait. Genetic correlations among harvest body weight, survival rate and body colour are insignificantly different and ranging from -0.25 to 0.37 (P > 0.05). These results implied that selection on one trait do not influence on responses of the other traits. GxE interaction for body weight and body colour between two tested environments is mostly negligible with genetic correlations ranging from 0.63 - 0.80 while it is important for survival trait (rg = -0.17 ± 0.40).

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