To see the other types of publications on this topic, follow the link: Heritabilitiy.
Journal articles on the topic 'Heritabilitiy'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Heritabilitiy.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Sari, Eka Meutia, Mohd Agus Nashri Abdullah, and Cut Hasnani. "Estimasi Nilai Heritabilitas Sifat Kuantitatif Sapi Aceh." Jurnal Agripet 16, no. 1 (April 1, 2016): 37. http://dx.doi.org/10.17969/agripet.v16i1.3530.
Full textAbstract:
ABSTRAK. Tujuan penelitian ini untuk mengestimasi nilai heritabilitas sifat kuantitatif pada sapi Aceh. Penelitian ini dilaksanakan di Balai Pembibitan Ternak Unggul (BPTU) Indrapuri Aceh Besar, dengan menggunakan metode survey (data primer dan data sekunder), dan analisis data menggunakan Rancangan Acak Lengkap Pola Searah. Parameter yang diamati dalam penelitian ini adalah nilai heritabilitas sifat kuantitatif meliputi panjang badan, tinggi gumba, lingkar dada, bobot lahir dan bobot sapih. Nilai heritabilitas bobot lahir 0,06 ± 0,29, bobot setahun 0,12 ± 0,32, bobot satu setengah tahun 0,37 ± 0,41. Hasil penelitian menunjukkan bahwa sifat kuantitatif pada sapi Aceh memiliki nilai heritabilitas yang rendah (bobot lahir) dan sedang (bobot setengah tahun). Perbedaan nilai heritabilitas disebabkan karena jumlah sampel yang digunakan, tempat dan waktu penelitian dan metode perhitungan yang berbeda. (Heritability estimation of quantitative traits in Aceh cattle) ABSTRACT. The objective of this research was to estimate the heritability of quantitative trait of Aceh cattle. This research was conducted in BPTU Indrapuri, Aceh Besar. The method used was survey, and the Completely Randomized Design Pattern Unidirectional was used to analyze the data. The parameter which was observed in this research was the heritability of quantitative trait including body length, body height, chest size, birth weight and weaning weight. Heritability for birthweight 0.06 ± 0.29, for yearling weight 0.12 ± 0.32, and heritability for the weight of one and a half years 0.37 ± 0.41. The result shows that the heritability of quantitative traits in Aceh cattle was low (birth weight). The difference in heritability was due to the number of samples used, the place and time of the research and different calculation methods.
2
Gezan, Salvador A., Timothy L. White, and Dudley A. Huber. "Achieving higher heritabilities through improved design and analysis of clonal trials." Canadian Journal of Forest Research 36, no. 9 (September 1, 2006): 2148–56. http://dx.doi.org/10.1139/x06-113.
Full textAbstract:
Clonal testing was studied under different environmental patterns and experimental designs through simulation with the criteria of maximizing broad-sense heritability estimates and genetic gain from clonal selection. Several experimental designs were studied together with three patterns of environmental variability. In addition, empirical 95% confidence intervals for heritability estimates were compared with Dickerson's approximate method. Other elements studied included (i) conditions under which different environmental patterns yield high or low heritabilities and (ii) effects of varying the number of ramets per clone. Row-column designs produced the highest mean individual broad- sense heritability, but these designs were only slightly more efficient than incomplete block designs with small block sizes. For all experimental designs, Dickerson's approximate method for estimating the variance of heritability estimates produced reasonable 95% confidence intervals but overestimated the upper confidence limit of complex designs. Larger heritabilities were found with higher tree-to-tree spatial correlations and lower amounts of microsite residual variance, and varying gradients had negligible influence. The effect of implementing Latinization was significant on increasing heritability, but small in practical terms, and was more important for patchy surfaces. Experiments with more ramets per clone yielded higher clonal mean heritabilities, and using between four and six ramets per clone per site is recommended.
3
Qadri, Aliyul, Erita Hayati, and Efendi Efendi. "Pendugaan Nilai Heritabilitas Karakter Agronomi Tanaman Padi (Oryza sativa L) Generasi F2." Jurnal Ilmiah Mahasiswa Pertanian 3, no. 4 (April 5, 2020): 125–31. http://dx.doi.org/10.17969/jimfp.v3i4.9197.
Full textAbstract:
Abstrak. Penelitian bertujuan untuk mendapatkan informasi tingkat heritabilitas tanaman padi generasi F2 hasil persilangan varietas Batutegi dangan IRBB-27. Penelitian ini dilaksanakan di rumah kaca Fakultas Pertanian, Universitas Syiah Kuala, Darussalam Banda Aceh. Pelaksanaan penelitian dimulai dari April sampai September 2017. Pendugaan nilai heritabilitas pada penelitian ini menggunakan pendugaan ragam lingkungan tidak langsung metode Mahmud-Kramer (Broad sense-per tanaman). Pendugaan nilai heritabilitas ini menggunakan data populasi P1, P2, dan F2. P1 dan P2 merupakan galur murni, sedangkan F2 merupakan turunan kedua dari persilangan P1 dan P2. Ragam fenotipe (σ2P) diduga dari σ2F2. Ragam lingkungan (σ2E) diduga dari √(σ2P1)(σ2P2). Pada karakter tinggi tanaman, jumlah malai, berat malai, berat 1000 butir, umur paner, dan potensi hasil memiliki nilai heritabilitas 92%, 55%, 51%, 89%, 64% dan 60% dengan kriteria tinggi. Sedangkan karakter panjang malai, dan persentase gabah bernas, memiliki nilai heritabilitas 29% dan 33% dengan kriteria sedang.Estimating the Heritability Value of Agronimic Character of Rice (Oryza sativa L) Generation F2Abstract. The aim of this research was to obtain information on the level of heritability of generation F2 rice produced by crossing of the Batutegi variety with IRBB-27. This research was carried out in the greenhouse of the Faculty of Agriculture, Syiah Kuala University, Darussalam Banda Aceh. The research starts from April to September 2017. Estimating the heritability value in this study uses indirect environmental estimation of the Mahmud-Kramer method (Broad sense- plant). Estimating this heritability value uses population data P1, P2 and F2. P1 and P2 are pure strains, while F2 is the second derivative of P1 and P2 crosses. Phenotype variance (σ2P) is assumed to be from σ2F2. Environmental variance (σ2E) is assumed to be from √(σ2P1) (σ2P2). In the character of plant height, panicle number, panicle weight, 1000 grain weight, paner age, and yield potential has a heritability value of 92%, 55%, 51%, 89%, 64% and 60% with high criteria. While the panicle length character, and the percentage of pithy grain, has a heritability value of 29% and 33% with medium criteria.
4
Dudi, N. Hilmia Dedi Rahmat. "EVALUASI BOBOT LAHIR DAN NILAI HERITABILITASNYA PADA SAPI BALI DI BPTU HPT PULUKAN BALI (Evaluated Means of Birth Weight and it’s Heritability Value in Bali Cattle at BPTU HMT Denpasar Bali)." JANHUS: Jurnal Ilmu Peternakan Journal of Animal Husbandry Science 2, no. 1 (March 29, 2018): 13. http://dx.doi.org/10.52434/janhus.v2i1.257.
Full textAbstract:
Abstrak
Bobot lahir merupakan parameter awal di dalam mengidentifikasi produktivitas seekor ternak dan pendugaan nilai heritabilitas suatu sifat merupakan parameter genetik yang penting didalm melakukan seleksi berdasarkan sifat tersebut. Penelitian ini bertujuan untuk mengevaluasi bobot lahir dan nilai heritabilitasnya pada sapi Bali di BPTU HMT Denpasar yang dapat digunakan sebagai dasar seleksi bibit berdasarkan bobot lahir. Peneilitian ini menggunakan 100 data bobot lahir sapi Bali, yang diperoleh dari 58 ekor sapi betina dan 42 ekor sapi jantan, sedangkan pendugaan heritabilitas bobot lahir menggunakan 99 data bobot lahir berasal dari 99 ekor induk dan lima pejantan. Bobot lahir dievaluasi menggunakan statistik deskriptif dan pendugaan nilai heritabilitas dianalisis menggunakan analisis sidik ragam pola Half sib. Hasil penelitian menunjukkan bobot lahir sapi Bali betina adalah 18,95 ± 2,16 kg dan jantan adalah 20,12 ± 2,19 kg. Nilai heritabilitas bobot lahir sapi Bali adalah 0,024 ± 0,08. Nilai heritabilitas bobot lahir di BPTU HMT Denpasar termasuk dalam kategori rendah.
Kata Kunci : Sapi Bali, Bobot Lahir, Heritabilitas
Abstract
Birth weight is the initial parameter to identify livestock productivity and estimated heritability value of the trait is an important genetic parameter to do the selection based on that trait. The objectives of this study were evaluated means of birth weight and it’s heritability value in Bali cattle at BPTU HMT Denpasar Bali, which can be used as the base of selection. This research used 100 birth weight data of Bali cattle, obtained from 58 female and 42 male calves, whereas the estimation of birth weight heritability using 99 birth weight data from 99 cows and five bulls. Birth weight was evaluated using descriptive statistic and estimated heritability value was analyzed using ANOVA (analysis of variance) based on pathernal half sib correlation. The results showed that the birth weight of female and males calves were 18.95 ± 2.16 kg 20.12 ± 2.19 kg respectively. The birth weight estimated heritability value of Bali cattle in BPTU HMT Denpasar was 0.024 ± 0.08 . this value was in low category.
Keywords : Bali cattle, Birth weight, Heretability
5
Mckeand, S. E., B. Li, J. E. Grissom, F. Isik, and K. J. S. Jayawickrama. "Genetic Parameter Estimates for Growth Traits from Diallel Tests of Loblolly Pine Throughout the Southeastern United States." Silvae Genetica 57, no. 1-6 (December 1, 2008): 101–10. http://dx.doi.org/10.1515/sg-2008-0016.
Full textAbstract:
Abstract Variation in heritability and in genetic correlation estimates were evaluated for juvenile tree height and volume for six testing areas of loblolly pine (Pinus taeda L.) in the southeastern United States. Variance components and their functions (heritability and type B genetic correlations) were estimated from 265 six-parent disconnected diallel series, tested in almost 1000 trials (4 tests per diallel series). Original data were collected at age 6 years from about one million trees (265 diallel series x 30 crosses x 36 trees per cross/site x 4 sites) planted in field tests. Genetic tests were from the second cycle of breeding in the North Carolina State University - Industry Cooperative Tree Improvement Program. The overall unbiased individual-tree narrow-sense heritability for height was 0.19 and for volume was 0.16. The broad-sense heritabilities for height (0.24) and for volume (0.22) were higher than narrow-sense heritabilities due to the presence of non-additive genetic variance. There were moderate regional differences in these estimates, with tests in the Lower Gulf Coastal Plain tending to have the highest heritabilities for growth traits. There was very little association between site index and heritability, but heritabilities were higher on sites with the highest survival and highest test precision. Genotype x environment interactions were generally low both for half-sib and full-sib families, indicating that families can be operationally deployed to different sites with little concern about unpredictable performance.
6
Beekman, Marian, Bastiaan T. Heijmans, Nicholas G. Martin, Nancy L. Pedersen, John B. Whitfield, Ulf DeFaire, G. Caroline M. van Baal, et al. "Heritabilities of Apolipoprotein and Lipid Levels in Three Countries." Twin Research 5, no. 2 (April 1, 2002): 87–97. http://dx.doi.org/10.1375/twin.5.2.87.
Full textAbstract:
AbstractThis study investigated the influence of genes and environment on the variation of apolipoprotein and lipid levels, which are important intermediate phenotypes in the pathways toward cardiovascular disease. Heritability estimates are presented, including those for apolipoprotein E and AII levels which have rarely been reported before. We studied twin samples from the Netherlands (two cohorts;n= 160 pairs, aged 13–22 andn= 204 pairs, aged 34–62), Australia (n= 1362 pairs, aged 28–92) and Sweden (n= 302 pairs, aged 42–88). The variation of apolipoprotein and lipid levels depended largely on the influences of additive genetic factors in each twin sample. There was no significant evidence for the influence of common environment. No sex differences in heritability estimates for any phenotype in any of the samples were observed. Heritabilities ranged from 0.48–0.87, with most heritabilities exceeding 0.60. The heritability estimates in the Dutch samples were significantly higher than in the Australian sample. The heritabilities for the Swedish were intermediate to the Dutch and the Australian samples and not significantly different from the heritabilities in these other two samples. Although sample specific effects are present, we have shown that genes play a major role in determining the variance of apolipoprotein and lipid levels in four independent twin samples from three different countries.
7
Barmawi, Maimun. "POLA SEGREGASI DAN HERITABILITAS SIFAT KETAHANAN KEDELAI TERHADAP COWPEA MILD MOTTLE VIRUS POPULASI WILIS X MLG2521." Jurnal Hama dan Penyakit Tumbuhan Tropika 7, no. 1 (March 4, 2007): 48–52. http://dx.doi.org/10.23960/j.hptt.1748-52.
Full textAbstract:
Segregation and Heritability of Cowpea Mild Mottle Virus Resistant Characters of Soybean Genotypes from Crosses Between Wilis and Mlg2521 Population. This research was conducted within July to October, 2005 at experiment station of Lampung University. The aims of this research were to evaluate the segreation and heritability of resitant characters at F2 population of Wilis x Mlg2521. The result showed that segregation of resistant characters segretate 13:3 of succeptible and resistant genotypes. Heritability in the narrow sense based on disease severity was 13,18% (low) and heritabilitas heritability in the broad-sense was 80,91% (high).
8
Crusio, Wim E. "Heritability estimates in behavior genetics: Wasn't that station passed long ago?" Behavioral and Brain Sciences 35, no. 5 (October 2012): 361–62. http://dx.doi.org/10.1017/s0140525x12000970.
Full textAbstract:
AbstractCharney describes several mechanisms that will bias estimates of heritability in unpredictable directions. In addition, the mechanisms described by Charney explain the puzzling fact that research in human-behavior genetics routinely reports higher heritabilities than animal studies do. However, I argue that the concept of heritability has no real place in human research anyway.
9
Borralho, N. M. G. "Heterogeneous selfing rates and dominance effects in estimating heritabilities from open-pollinated progeny." Canadian Journal of Forest Research 24, no. 5 (May 1, 1994): 1079–82. http://dx.doi.org/10.1139/x94-143.
Full textAbstract:
Estimates of heritability from open-pollinated progeny trials were generally biased by heterogeneous selfing across families and by the presence of dominance, even when the intraclass correlation between sibs was adjusted for the average number of full- and half-sibs and for relatedness among the parents in the population. For high levels of selfing, with a constant selfing rate and inbreeding depression across families, dominance causes a downward bias in the heritabilities. Where rates of selfing and inbreeding depression varied, heritability was overestimated. However, except for low heritabilities, bias was of little practical importance, providing the correct coefficient of relationship among open-pollinated progeny was used.
10
Magnussen, Steen. "A distribution model for heritability." Genome 35, no. 6 (December 1, 1992): 931–38. http://dx.doi.org/10.1139/g92-143.
Full textAbstract:
A regression model to predict quantiles of narrow sense individual and family mean heritabilities is developed and used to predict confidence intervals either directly or via a generalized beta distribution model. Extensive simulations of balanced sib analysis trials in randomized complete block designs and normal distributed environmental and additive genetic effects confirmed that heritabilities follow a beta distribution even in cases with up to 10% of the data missing at random. The new model is both more accurate and more precise than commonly used alternatives based on "exact" χ2 distributions and Satterthwaites approximations to the degrees of freedom. Estimates of the expected heritability and a Taylor approximation of the standard error of the heritability are needed as input to the quantile model. Applications of the presented models for estimating confidence intervals and as an aid in the design of experiments are provided.Key words: heritability, confidence intervals, beta distribution, quantiles, experimental design.
11
Eyler, Lisa T., Chi-Hua Chen, Matthew S. Panizzon, Christine Fennema-Notestine, Michael C. Neale, Amy Jak, Terry L. Jernigan, et al. "A Comparison of Heritability Maps of Cortical Surface Area and Thickness and the Influence of Adjustment for Whole Brain Measures: A Magnetic Resonance Imaging Twin Study." Twin Research and Human Genetics 15, no. 3 (June 2012): 304–14. http://dx.doi.org/10.1017/thg.2012.3.
Full textAbstract:
Understanding the genetic and environmental contributions to measures of brain structure such as surface area and cortical thickness is important for a better understanding of the nature of brain-behavior relationships and changes due to development or disease. Continuous spatial maps of genetic influences on these structural features can contribute to our understanding of regional patterns of heritability, since it remains to be seen whether genetic contributions to brain structure respect the boundaries of any traditional parcellation approaches. Using data from magnetic resonance imaging scans collected on a large sample of monozygotic and dizygotic twins in the Vietnam Era Twin Study of Aging, we created maps of the heritability of areal expansion (a vertex-based area measure) and cortical thickness and examined the degree to which these maps were affected by adjustment for total surface area and mean cortical thickness. We also compared the approach of estimating regional heritability based on the average heritability of vertices within the region to the more traditional region-of-interest (ROI)-based approach. The results suggested high heritability across the cortex for areal expansion and, to a slightly lesser degree, for cortical thickness. There was a great deal of genetic overlap between global and regional measures for surface area, so maps of region-specific genetic influences on surface area revealed more modest heritabilities. There was greater inter-regional variability in heritabilities when calculated using the traditional ROI-based approach compared to summarizing vertex-by-vertex heritabilities within regions. Discrepancies between the approaches were greatest in small regions and tended to be larger for surface area than for cortical thickness measures. Implications regarding brain phenotypes for future genetic association studies are discussed.
12
Dochtermann, Ned A., Tori Schwab, Monica Anderson Berdal, Jeremy Dalos, and Raphaël Royauté. "The Heritability of Behavior: A Meta-analysis." Journal of Heredity 110, no. 4 (May 22, 2019): 403–10. http://dx.doi.org/10.1093/jhered/esz023.
Full textAbstract:
AbstractThe contribution of genetic variation to phenotypes is a central factor in whether and how populations respond to selection. The most common approach to estimating these influences is via the calculation of heritabilities, which summarize the contribution of genetic variation to phenotypic variation. Heritabilities also indicate the relative effect of genetic variation on phenotypes versus that of environmental sources of variation. For labile traits like behavioral responses, life history traits, and physiological responses, estimation of heritabilities is important as these traits are strongly influenced by the environment. Thus, knowing whether or not genetic variation is present within populations is necessary to understand whether or not these populations can evolve in response to selection. Here we report the results of a meta-analysis summarizing what we currently know about the heritability of behavior. Using phylogenetically controlled methods we assessed the average heritability of behavior (0.235)—which is similar to that reported in previous analyses of physiological and life history traits—and examined differences among taxa, behavioral classifications, and other biologically relevant factors. We found that there was considerable variation among behaviors as to how heritable they were, with migratory behaviors being the most heritable. Interestingly, we found no effect of phylogeny on estimates of heritability. These results suggest, first, that behavior may not be particularly unique in the degree to which it is influenced by factors other than genetics and, second, that those factors influencing whether a behavioral trait will have low or high heritability require further consideration.
13
Browning, S. J., T. P. Riordan, R. K. Johnson, and J. Johnson-Cicalese. "Heritability Estimates of Turf-type Characteristics in Buffalograss." HortScience 29, no. 3 (March 1994): 204–5. http://dx.doi.org/10.21273/hortsci.29.3.204.
Full textAbstract:
Buffalograss [Buchloë dactyloides (Nutt.) Engelm] is a drought-resistant, dioecious species, native to the Central Great Plains, which shows excellent potential as a low-maintenance turfgrass. Although buffalograss can be propagated vegetatively, there is a need for seeded turf-type cultivars. To assist in developing seeded cultivars, heritabilities of turf characteristics were estimated. Heritabilities from maternal half-sib analyses ranged from h2 = 0.04 ± 0.03 for the 1988 uniformity rating to h2 = 0.62 ± 0.26 for the 1989 spring color rating. Heritability estimates calculated from offspring-parent regression were also variable and generally lower than maternal half-sib analysis. The results suggest that some turf characteristics are highly heritable and that growing conditions markedly affect heritability estimates.
14
de Araujo, Marcelo R. A., and B. E. Coulman. "Parent-offspring regression in meadow bromegrass (Bromus riparius Rehm.): Evaluation of two methodologies on heritability estimates." Canadian Journal of Plant Science 84, no. 1 (January 1, 2004): 125–27. http://dx.doi.org/10.4141/p02-119.
Full textAbstract:
To determine the nature and extent of inflation of estimates of heritabilities by parent-offspring regression methods, 40 clones of meadow bromegrass (Bromus riparius Rehm.) and their half-sib progenies were studied in completely randomized block design trials, with six replications in Saskatoon and Melfort, Canada. Clones and progenies were evaluated for dry matter yield, seed yield, plant height, fertility index and harvest index. The results of the analysis showed a consistent inflation of heritability estimates derived from the simple parent-offspring regression, when compared to the regression estimate by variance-covariance analysis. The two methods successfully removed the environmental covariances from the estimates. However, in the simple regression analysis, error covariance was not removed from the numerat or; therefore, heritabilities estimated by this methodology were higher than those estimated by the variance-covariance method. It was concluded that estimates derived from variance-covariance analysis provide less biased estimates of heritability. Key words: Regression analysis, heritability, meadow bromegrass
15
(Sumadi), Sumadi, Jatmika Prajayastanda, and Nono Ngadiyono. "ESTIMASI HERITABILITAS SIFAT PERTUMBUHAN DOMBA EKOR GEMUK DI UNIT PELAKSANA TEKNIS PEMBIBITAN TERNAK-HIJAUAN MAKANAN TERNAK GARAHAN." Buletin Peternakan 38, no. 3 (October 1, 2014): 125. http://dx.doi.org/10.21059/buletinpeternak.v38i3.5246.
Full textAbstract:
<p>Sheep is one of popular ruminants in Indonesia, because sheep is one one of source of animal protein, and also easy and convenient in breeding. Therefor, they should be developed, preserved and increased through improvement of genetic quality by selection and mating control in the breeding program. Arrangement of a breeding program requires the values of genetic parameter namely heritability. The purpose of this study was to estimate the growth heritability value of Fat Tailed sheep in UPT PT-HMT Garahan, Jember, East Java. Data were collected from progeny, birth weight and weaning weight of Fat Tailed sheep from 2007 to 2012 in UPT-HMT Garahan, Jember. Data were corrected by sex, type of birth and weaning of age. Data were analyzed using the heritability of paternal halfsib correlations and nested method of analysis. The estimation of heritabilities using paternal halfsib correlation were 0.85±0.39; 0.89±0,41 and 0.67±0.37 for birth weight, weaning weight and pre weaning average daily gain (ADG). While, heritabilities estimated from nested method were 0.89±0,48 (h2 S); -0.11±0.33 (h2 D); 0.39±0.28 (h2 S+D); 0.71±0.50 (h2 S); 0.69±0.52 (h2 D); 0.70±0.33 (h2 S+D); 0.47±0.44 (h2 S); 0.72±0.56 (h2 D); 0.60±0.32 (h2 S+D) for birth weight, weaning weight an pre weaning ADG, respectively. All growth heritabilities of Fat Tailed sheep in high category.</p><p><br />(Keyword: Fat Tailed sheep, Growth characters, Heritability)</p>
16
Xie, Chang-Yi, Y. B. Fu, and A. D. Yanchuk. "Accuracy of Ranking Individuals in Field Tests of Different Designs: A Computer Simulation." Silvae Genetica 55, no. 1-6 (December 1, 2006): 70–77. http://dx.doi.org/10.1515/sg-2006-0011.
Full textAbstract:
Abstract A computer simulation was conducted to investigate the accuracy of ranking individual trees in field tests of different designs. A test population that consists of 900 trees from 45 full-sib families generated by three 6-parent disconnected half-diallels was considered. One incomplete block design with single-tree plots and four complete block designs with 1, 2, 4, and 10-tree row plots were examined. Various narrow-sense heritabilities, site variation patterns (patch sizes and gradient slopes), and two levels of dominant to additive genetic variance ratios (0 and 0.30) were evaluated. Results indicate that the accuracy of ranking depends more on the heritability of the trait and less on the magnitude of the dominant genetic variance, site variation patterns, and field designs. With patchy site variation, differences in ranking accuracy were observed for different designs, but became smaller with higher heritabilities. Impact of environmental gradient on the accuracy of individual ranking was negligible. Incomplete block design with single-tree plots (ICB1) provided the most accurate ranking when heritability was low while complete block design with 2-tree plots (RCB2) appeared to be the best when heritability was high. Large row plot designs were among the least effective in all the simulated scenarios. For traits with medium heritabilities, the statistical efficiencies of ICB1 and RCB with 1 and 2-tree plots are comparable.
17
Wassmuth, R., E. Gernand, H. Lenz, and C. Mendel. "Futteraufnahme und Fressverhalten wachsender Lämmer – 1. Mitteilung: Heritabilitäten und genetische Korrelationen." Archives Animal Breeding 51, no. 4 (October 10, 2008): 366–71. http://dx.doi.org/10.5194/aab-51-366-2008.
Full textAbstract:
Abstract. Title: Feed intake and eating behaviour of growing lambs, 1st communication: heritabilities and genetic correlations In the test stations “Grub” (Bavaria) and “Schöndorf” (Thuringia) data were collected on lambs of the breeds Merinolandschaf and Merino Longwool. Feed intake during the whole test period (FAP), feed efficiency (FAW), daily feed intake (TFM), the number of daily visits (TBH) and eating time (TBD) of lambs were measured. In total, data from 1,608 lambs with 37,161 daily records in “Grub” and 1,424 lambs with 35,356 daily records in “Schöndorf” were included. The aim of the present study was to estimate heritabilities and genetic correlations for different traits of feed intake and eating behaviour. In “Schöndorf” the heritability of FAP and FAW was 0.29 and 0.32, respectively. In the test station “Grub” the heritability of the same traits was 0.58 and 0.57, respectively. The heritability of TBH, TBD and TFM were 0.33, 0.25 and 0.05, respectively, in “Schöndorf” and 0.49, 0.36 and 0.10, respectively, in “Grub”. The genetic correlations between the eating behaviour traits TBH and TBD on one hand and feed intake (FAP, FAW, TFM) on the other hand were low. It could be concluded that feed intake as well as eating behaviour showed considerable variances and heritabilities. Further, eating behaviour was not a good indicator of feed intake.
18
Yu, Yiran, James Harding, and Thomas Famula. "ESTIMATION OF VARIANCE COMPONENTS AND HERITABILITY FOR FLOWERING TIME AND CUT-FLOWER YIELD FOR THE DAVIS POPULATION OF GERBERA USING RESTRICTED MAXIMUM LIKELIHOOD (REML)." HortScience 25, no. 9 (September 1990): 1173d—1173. http://dx.doi.org/10.21273/hortsci.25.9.1173d.
Full textAbstract:
Additive genetic components of variance and narrow-sense heritabilities were estimated for flowering time and cut-flower yield for generations 8-13 of the Davis population of gerbera, using the least squares (LS) and restricted maximum likelihood (REML)methods. Estimates of heritability for flowering time were 0.54 and 0.50 using REML and LS, respectively, indicating a close agreement between the two methods. However, estimates of heritability for cut-flower yield were 0.30 and 0.46 from REML and LS. This may result from the fact that cut-flower yield was selected in each generation; flowering time was not. Realized heritability for cut-flower yield was estimated to be 0.26 which agreeded more closely with the heritability estimated from REML. The advantages of REML, and its applications in the estimation of components of genetic variance and heritability of plant populations are discussed.
19
Phillips, R. A., and R. W. Furness. "Measurement of heritability of hatching date and chick condition in parasitic jaegers." Canadian Journal of Zoology 76, no. 12 (December 1, 1998): 2290–94. http://dx.doi.org/10.1139/z98-187.
Full textAbstract:
There are few published studies of heritability of reproductive traits in long-lived birds. In parasitic jaegers (Stercorarius parasiticus) breeding on Foula, Shetland, there was no significant heritability in calendar hatching date or relative hatching date, using either mother-offspring, father-offspring, or pooled mother/father - offspring regressions. By contrast, chick body condition (mass corrected for size) was highly heritable. Both traits were important determinants of chick survival from banding until recruitment. High heritability of chick condition was therefore surprising, as characters closely related to fitness are generally assumed to have low heritability. However, chick condition may include a component of structural size, and morphological traits tend to have high heritabilities despite frequently having an important influence on fecundity or viability in birds.
20
Mashhadi, M. Hosseinpour, F. Eftekhari Shahroudi, and R. Valizadeh. "Evaluation genetic parameters for weight at different ages in Baluchi breed of sheep." Proceedings of the British Society of Animal Science 2003 (2003): 145. http://dx.doi.org/10.1017/s1752756200013041.
Full textAbstract:
Improving breeding values and breeding programs should be done based on genetic potential. The range of additive direct heritability and maternal environment heritability for birth weight is about 0.07 to 0.22 and 0.1 to 0.33 respectively the range of these values for the following weights are 0.09- 0.58 and 0.01- 0.17. the objective of this study was to predict the direct additive genetic effect, maternal genetic effect and heritabilities of lamb weight traits in baluchi breed of sheep.
21
Wall, Marisa M., Ayaz Mohammad, and Joe N. Corgan. "Heritability Estimates of the Pungency and Single-center Traits in Onion." HortScience 30, no. 4 (July 1995): 822E—822. http://dx.doi.org/10.21273/hortsci.30.4.822e.
Full textAbstract:
Heritabilities of the pungency and single-center traits were estimated in onion breeding lines using selection response and half-sib family analyses. Pungency was determined by measuring enzymatically produced pyruvic acid in individual bulbs. After one generation of selection, pungency was lowered by 0.37 and 0.42 μmol pyruvic acid/gram fresh weight in the breeding lines 90-61-1 and 89-69-8, respectively, and realized heritabilities of 0.21 and 0.51 were estimated. Heritability estimates calculated through half-sib progeny analysis were 0.53, 0.48, and 0.25 for pungency in the breeding lines 90-61-1, 90-62, and 89-69-8, respectively. The number of single-centered onions was increased by 19% and 22% in the lines 90-62 and 89-69-8, respectively, after one generation of selection, and the realized heritability estimates were 0.37 and 0.34, respectively.
22
Cornelius, Jonathan. "Heritabilities and additive genetic coefficients of variation in forest trees." Canadian Journal of Forest Research 24, no. 2 (February 1, 1994): 372–79. http://dx.doi.org/10.1139/x94-050.
Full textAbstract:
Estimates of individual-tree narrow-sense heritability and additive genetic coefficient of variation of seven traits of forest trees were compiled from 67 published papers. Distributions of the values for each trait were characterized and compared by calculating medians and running Kolmogorov–Smirnov and Wilcoxon signed-rank tests. Generalizations are possible about at least some of the traits examined. Heritability of wood specific gravity was almost always above 0.3 (median 0.48). Heritabilities for other traits tended to be low: medians ranged from 0.185 to 0.26, and individual values generally ranged from 0.1 to 0.4. Evidence that heritabilities of form traits tend to be higher than those of growth traits was weak. The analysis of additive genetic coefficients of variation suggested that specific gravity tends to have lower values than other traits (median 5.1%), while height and diameter (medians 8.5 and 8.6%, respectively) had lower values than straightness (median 11.65%). Individual-tree volume showed the highest levels of additive genetic coefficient of variation (median 20.3%). The levels of additive genetic variation and heritabilities suggest that reasonable levels of genetic gain can be achieved by screening relatively low numbers of trees.
23
Pedersen, N. L., R. Plomin, J. R. Nesselroade, and G. E. McClearn. "A Quantitative Genetic Analysis of Cognitive Abilities during the Second Half of the Life Span." Psychological Science 3, no. 6 (November 1992): 346–53. http://dx.doi.org/10.1111/j.1467-9280.1992.tb00045.x.
Full textAbstract:
Little is known about the importance of genetic effects on individual differences in cognitive abilities late in life. We present the first report from the Swedish Adoption/Twin Study of Aging (SATSA) for cognitive data, including general cognitive ability and 13 tests of specific cognitive abilities. The adoption/twin design consists of identical twins separated at an early age and reared apart (46 pairs), identical twins reared together (67 pairs), fraternal twins reared apart (100 pairs), and fraternal twins reared together (89 pairs); average age was 65 years. Heritability of general cognitive ability in these twins was much higher (about 80%) than estimates typically found earlier in life (about 50%). Consistent with the literature, heritabilities of specific cognitive abilities were lower than the heritability of general cognitive ability but nonetheless substantial. Average heritabilities for verbal, spatial, perceptual speed, and memory tests were, respectively, 58%, 46%, 58%, and 38%.
24
McKAY, R. M., and G. W. RAHNEFELD. "HERITABILITY OF TEAT NUMBER IN SWINE." Canadian Journal of Animal Science 70, no. 2 (June 1, 1990): 425–30. http://dx.doi.org/10.4141/cjas90-054.
Full textAbstract:
Heritabilities were estimated for teat number in nine populations of swine over two time periods. From 1962 to 1974 the populations included Lacombe, Yorkshire, and Lacombe × Yorkshire. In this data set, only total teat number was recorded. From 1982 to 1988 three purebred populations (Landrace, Yorkshire, and Hampshire) and three crossbred populations (Landrace-Yorkshire rotation, Landrace × Yorkshire, and Landrace × Hampshire) were represented and total teat number and the number of teats anterior and posterior to the navel were recorded. Heritabilities for total teat number were greater in the 1982–1988 data (ranging from 0.27 to 0.47) than in the 1962–1974 data (ranging from 0.20 to 0.32). The heritability of posterior teat numbers (ranging from 0.08 to 0.39) was generally larger than the heritability of anterior teat numbers (ranging from 0.03 to 0.21) and both were considerably less than the heritability of total teat number. Genetic and phenotypic correlations were calculated for the relationships between anterior and posterior teat numbers (AP), anterior and total teat numbers (AT), and posterior and total teat numbers (PT). The relative magnitudes of the genetic and phenotypic correlations with respect to AP, AT, and PT revealed that selection for increased total teat number would increase the number of anterior and posterior teats. However, the larger genetic correlations for PT relative to AT would lead to a greater increase in posterior teat number than anterior teat number. Key words: Pigs, teat number, heritability, genetic correlation, phenotypic correlation
25
Chegini, Arash, Navid Ghavi Hossein-Zadeh, Seyed Hossein Hosseini-Moghadam, and Abdol Ahad Shadparvar. "Genetic correlation estimates between milk production traits, mastitis and different measures of somatic cells in Holstein cows." Animal Production Science 59, no. 6 (2019): 1031. http://dx.doi.org/10.1071/an17325.
Full textAbstract:
The objective of this study was to estimate genetic parameters including repeatability, heritability as well as genetic and environmental relationships between 305-day milk yield, milk fat and protein yield (Fat and Pro), milk fat and protein percentages (Fat% and Pro%), mastitis (Mast), number of mastitis occurrence and different measurements of somatic cell counts using linear and threshold animal as well as linear and threshold sire models in Holstein cows of Iran. Records of 33851 first lactation Holstein cows from five large dairy herds with calving dates from March 2002 to September 2014 were analysed, using Gibbs sampling methodology. Heritabilities of production traits estimated by linear animal model ranged from 0.14 (Fat%) to 0.29 (Pro%). Generally, udder health traits had low heritability (ranged from 0.005 to 0.10). Estimates of heritability for Mast using linear models were higher than those obtained with threshold models. However, in general estimates of heritabilities using threshold models were higher than those from linear models. There were unfavourable genetic correlations between production traits and Mast, which implies that breeding programs with emphasis on 305-day milk yield will experience deterioration in udder health. Despite low heritability of udder health traits, genetic variability exists for these traits that allow selecting superior animals and increasing resistance to Mast and animal welfare. Considering relatively high ratio of permanent environmental variance for Mast, culling decisions can be made with higher accuracy in order to reduce Mast incidence phenotypically over time.
26
Collins Kimutai, Manje Gowda, and Oliver Kiplagat. "Trait-QTL-heritability of grain yield and other agronomic traits under low nitrogen conditions in bi-parental maize populations." International Journal of Biological and Pharmaceutical Sciences Archive 2, no. 1 (August 30, 2021): 096–116. http://dx.doi.org/10.53771/ijbpsa.2021.2.1.0072.
Full textAbstract:
Limited or low Nitrogen is a wanting abiotic stress in maize mainly in Sub-Sahara Africa, affecting yields and quality development of maize crop. As an approach to getting a breeding solution; mapping of QTLs and understanding the heritability factor can provide useful information and guide for breeders in developing low nitrogen resilient maize. QTL mapping which is a molecular breeding component forms an actual basis in estimation of genomic regions associated to the expression of quantitative traits, and how heritable are such traits. Conducting a selection for Low N-tolerance is challenging due to its complex nature with strong interaction between genotypes and environments; therefore, marker assisted breeding is key to improving such complex traits, but at the same time requires markers associated with the trait of interest. In this study, three bi-parental populations were subjected to either or both low and optimum N conditions to detect and determine the QTLs heritability for grain yield and other agronomic traits. Essential to the study; genotype by environmental interaction, significance and heritability was examined for each population with most traits expressing low (<0.2) and moderate to high heritabilities (0.3>). These QTLs with high heritabilities across environments will be of great value for rapid introgression into maize populations using marker assisted selection approach. The study was a preliminary and therefore require further validation on heritability and fine mapping for them to be useful in MAS.
27
Riska, B., T. Prout, and M. Turelli. "Laboratory estimates of heritabilities and genetic correlations in nature." Genetics 123, no. 4 (December 1, 1989): 865–71. http://dx.doi.org/10.1093/genetics/123.4.865.
Full textAbstract:
Abstract A lower bound on heritability in a natural environment can be determined from the regression of offspring raised in the laboratory on parents raised in nature. An estimate of additive genetic variance in the laboratory is also required. The estimated lower bounds on heritabilities can sometimes be used to demonstrate a significant genetic correlation between two traits in nature, if their genetic and phenotypic correlations in nature have the same sign, and if sample sizes are large, and heritabilities and phenotypic and genetic correlations are high.
28
Atuahene-Amankwa, G., and T. E. Michaels. "Genetic variances, heritabilities and genetic correlations of grain yield, harvest index and yield components for common bean (Phaseolus vulgaris L.) in sole crop and in maize/bean intercrop." Canadian Journal of Plant Science 77, no. 4 (October 1, 1997): 533–38. http://dx.doi.org/10.4141/p96-168.
Full textAbstract:
Breeding of common bean (Phaseolus vulgaris L.) for intercropping with maize (Zea mays L.) is usually done in bean sole crop nurseries. However, bean cultivar evaluations have identified significant cultivar × cropping system interactions. The objective of this study was to determine whether intercrop and sole cropping systems have different effects on phenotypic and genetic variance components of bean populations. Unselected F2 and F3 populations of 16 crosses of common bean were evaluated in the two cropping systems at Elora and Woodstock, Ontario, Canada, in 1993 and 1994. Significant population × cropping system interaction was found for grain yield and pods per plant. Genetic correlations between cropping systems were lowest for grain yield and pods per plant and highest for seed weight and seeds per pod. There were few differences between cropping systems for genetic variances. Genotype × location variance was higher in intercrop than in sole crop. Broad-sense heritabilities and narrow-sense heritabilities for most traits were comparable between cropping systems. The exception was pods per plant, which showed greater heritability in sole crop. Realized heritability of grain yield was greater in intercrop. We conclude that single plant selection as done with the pedigree system of breeding should be effective in intercrop. Key words: Genetic variances, heritability, intercrop, Phaseolus vulgaris
29
Svensson, Linus, and Helena Persson. "Quantitative genetics of stamen fertility in Spergularia salina (Caryophyllaceae)." Canadian Journal of Botany 72, no. 11 (November 1, 1994): 1598–604. http://dx.doi.org/10.1139/b94-197.
Full textAbstract:
Heritability of stamen fertility was studied in Spergularia salina (Caryophyllaceae), a selfing annual that shows extensive phenotypic variation in stamen fertility. Variation within and among 70 maternal families, derived from plants representing two natural populations from Sweden, was used to estimate heritabilities of stamen fertility for each of the 10 stamen positions in the flower. The hierarchical design of the study allowed partitioning of variation among four levels of organization using nested analysis of variance. Heritabilities ranged from 0.27 to 0.65 for stamen positions in the antipetalous whorl of stamens and from 0.18 to 0.67 for positions in the antisepalous whorl. When stamen fertility was pooled across all stamen positions of a flower, the heritability was 0.73 in both populations. The nested ANOVA indicated that antipetalous stamen positions have comparatively higher proportions of among-family and among-population variation than the antisepalous stamen positions. Furthermore, highly significant genetic correlations exist between the two antisepalous stamen positions STA 2 and STA 8 and among the other eight positions but not so between these two groups. The relationship between tetraploidization and stamen number reductions in Caryophyllaceae is discussed. Key words: Spergularia salina, stamen fertility, stamen position, heritability, hierarchical analysis of variance, quantitative genetics.
30
Keightley, P. D., M. J. Evans, and W. G. Hill. "Effects of multiple retrovirus insertions on quantitative traits of mice." Genetics 135, no. 4 (December 1, 1993): 1099–106. http://dx.doi.org/10.1093/genetics/135.4.1099.
Full textAbstract:
Abstract To assess the potential to generate quantitative genetic variation by insertional mutagenesis in a vertebrate, lines of mice in which many provirus vector inserts segregated at a low initial frequency on an inbred background (insert lines) were subjected to divergent artificial selection on body weight at 6 weeks and responses and heritability estimates compared to control lines lacking inserts. Heritability estimates were more than 1.5 times greater in the insert lines than in the controls, but because the phenotypic variance was substantially higher in the insert lines the genetic variance was about 3 times greater. Realized heritability estimates tended to be lower than heritabilities estimated by an animal model which utilizes information in covariances between all relatives in the data set. A surprisingly large response to selection occurred in the inbred control line. Insert lines were about 20% less fertile than controls. Division of the selection lines into inbred sublines in the later generations of the experiment revealed substantially greater variation among sublines of the insert lines than among the controls. Heritabilities were similar to typical estimates for the trait in outbred populations. In conclusion, there was clear evidence of extra variation deriving from inserts, which has yet to be attributed to individual genes.
31
MBAP, S. T. "A NOTE ON THE HERITABILITY ESTIMATES OF BIRTH WEIGHT AND CALVING INTERVAL OF WHITE FULANI CATTLE IN IBADAN." Nigerian Journal of Animal Production 23, no. 2 (January 12, 2021): 101–2. http://dx.doi.org/10.51791/njap.v23i2.2231.
Full textAbstract:
Heritabilities of birth weight and calvin interval in White Fulani Cattle were White Fulani, estimated using data from seven sires and 147 and dams collected in Ibadan between 1970 and. 1982. The heritability estimates were 0.21±0.26 for birth weight and 0.012±0.16 for calving interval.
32
Vanderhout, Ryley J., Michelle Yahiro, Benjamin Wood, Shai Barbut, Jeff S. Mohr, and Christine F. Baes. "41 Estimating the heritability of meat quality traits in turkeys." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 18–19. http://dx.doi.org/10.1093/jas/skaa278.035.
Full textAbstract:
Abstract Genetic selection for improved meat quality traits has been successfully implemented in many livestock species. The objective of this study was to estimate the heritability of several meat quality traits to assess their selection potential in turkeys. Pedigree toms (n = 1,033) were processed at a commercial facility and live weight, breast meat yield (as a percentage of live weight), ultimate pH, color (CIELAB values), drip loss, cooking loss, and shear force were recorded on M. pectoralis superficialis (fillet). White striping was also rated on a 1–4 scale. Heritabilities were estimated using univariate animal models in ASReml version 4.1. Hatch week and age at slaughter were included as fixed effects in the mode,l and 32 generations of pedigree records were used. Breast meat yield (h2 = 0.62; SE = 0.090) showed the highest heritability and was higher compared to previous estimates, probably due to the smaller sample size. Live weight (h2 = 0.31; SE = 0.078), ultimate pH (h2 = 0.36; SE = 0.087), lightness (h2 = 0.28; SE = 0.086), redness (h2 = 0.22; SE = 0.075), and white striping score (h2 = 0.27; SE = 0.085) all had moderate heritabilities. The estimate for ultimate pH was similar to previous studies in broilers but was high compared to previous studies in turkeys. Estimates for color were similar to those found in previous studies involving turkeys. Drip loss and cooking loss had similar heritability estimates of 0.13 (SE = 0.071) and 0.10 (SE = 0.064), respectively, which were akin to previous estimates in pork. Shear force (h2 = 0.02; SE = 0.056) was found to have a very low heritability. In conclusion, the heritability estimates provided in this study show great potential for the inclusion of meat quality traits in selection programs of turkeys. This study is part of a larger project working towards the implementation of genomic information in the selection of turkeys for improved meat quality.
33
Hoff, R. J. "Resistance to western gall rust in artificially inoculated ponderosa pine." Canadian Journal of Forest Research 21, no. 9 (September 1, 1991): 1316–20. http://dx.doi.org/10.1139/x91-185.
Full textAbstract:
Seedlings from 80 open-pollinated families of ponderosa pine (Pinusponderosa Laws.) were inoculated with western gall rust (Endocronartiumharknessii (J.P. Moore) Y. Hiratsuka) at the beginning of their 2nd year of growth. The overall infection level was 41 %, with a family heritability of 0.76. Several resistance responses were evident, heritabilities of which ranged from moderate to high; i.e., for seedlings with no symptoms, the heritability value was 0.60, while for trees with bark reactions that prevented gall formation, the heritability value was 0.71. There were three such types of bark reactions, for which heritability values were 0.36, 0.58, and 0.60. Heritability values of 0.38, 0.41, and 0.45 were found for trees with dead galls, rust-killed trees, and rate of gall appearance, respectively. Resistance of ponderosa pine to western gall rust is not only high but highly variable and exhibits a rich assortment of resistance reactions that probably account for the low level of gall-rust damage. The findings emphasize the importance of maintaining resistance in ponderosa pine tree-improvement programs.
34
unggul abrianto, ignatius maria, Luqman Hakim, and V. M. A. Nurgiartiningsih. "Pendugaan heritabilitas rill (realized heritability) dan kemajuan genetik produksi telur itik mojosari." Jurnal Ilmu-Ilmu peternakan 27, no. 2 (July 1, 2017): 74–80. http://dx.doi.org/10.21776/ub.jiip.2017.027.02.09.
Full text
35
Djedovic, Radica, Vladan Bogdanovic, Gligorije Trifunovic, Radmila Beskorovajni, and Dragan Stanojevic. "The evaluation of genetic parameters of the type of calving in the population of Holstein Friesian cows." Genetika 45, no. 1 (2013): 41–49. http://dx.doi.org/10.2298/gensr1301041d.
Full textAbstract:
Genetic parameters (heritability coefficients and genetic correlations) of the type of calving, number of stillbirths and birth weight have been evaluated in the population of Holstein Friesian cattle breed. Data sets have been analysed by means of the Mixed Least Square Model (LSMLMW). Besides a random effect of bull-sires, the model has also included the fixed effects of farm, season, sex, the evaluation of viability of calves and types of birth. Estimated heritability values and heritability errors for the type of calving (TC), number of stillbirths (SB) and birth weight (BWT) were low: 0.190 ? 0.062; 0.018 ? 0.006 and 0.149 ? 0.051, respectively. Heritabilities of the analysed traits were evaluated on the grounds of the calves` bull-sires additive value (direct heritability). The values of the genetic correlation coefficients between examined traits ranged from - 0.251 (correlation between the type of calving and number of stillbirths) to 0.340 (correlation between the number of stillbirths and birth weight).
36
Diego, Vincent P., Marcio A. Almeida, Bernadette W. Luu, Karin Haack, Meera B. Chitlur, Afshin Ameri, Long V. Dinh, et al. "Genetics of Factor VIII Inhibitor Development in Hemophilia Patients: Novel Statistical Approaches in the PATH Study." Blood 132, Supplement 1 (November 29, 2018): 1199. http://dx.doi.org/10.1182/blood-2018-99-120021.
Full textAbstract:
Abstract Here we apply state-of-the-art statistical genetic approaches toward investigating the genetic architecture of factor VIII (FVIII) inhibitor (FEI) development in Hemophilia A (HA). A total of 442 North American HA patients (237 Whites and 205 Blacks; 88% severely affected) enrolled in the PATH Study were: 1) ImmunoChip genotyped at ~167,000 single nucleotide polymorphisms (SNPs) in genes previously implicated in autoimmune disease risk; 2) Evaluated by DNA sequencing and assays for the recurrent intron (I)1 and I22 inversions to identify their causative F8 mutations; and 3) Tested with the Bethesda assay to determine their FEI status. The ImmunoChip genotypes were used to construct a genetic relationship matrix (GRM), denoted by K, following our previously published method,1 and the F8 sequence data along with results from the I1 and I22 inversion assays were used to construct a shared F8-mutation matrix, denoted by F. We analyzed a dichotomous FEI variable under the statistical genetic threshold/liability model (a probit regression in the fixed effects) in conjunction with a variance components model for the FEI liability phenotypic covariance matrix, denoted by P, to model potentially important random effects. For the latter, we specifically assumed independent additive genetic, F8-mutation, and residual environmental random effects. By the independence assumption, the covariance matrix is then decomposable as a sum of the additive genetic (Va), F8-mutation (Vf), and residual environmental (Ve) variances respectively structured by K, F, and the identity matrix I. The variance component model is given as: P = K*Va + F*Vf + I*Ve. Heritability, denoted by h2, is defined as the ratio of Va to the total phenotypic variance (Vp): h2 = Va / Vp. We can further speak of the total heritability given as: h2t = h2r + h2f + h2snp, where the subscripts t, r, f, and snp respectively denote total, residual additive genetic, F8-mutation-specific, and SNP heritabilities. Using eigenstructure methods,2 we can compute power under a simpler model in which Va and Vf are combined as a single variance component. We computed power to detect genetic association as measured by SNP-specific heritability for a set of 403 SNPs in or near 14 candidate immune response genes previously implicated in FEI risk. To account for multiple hypothesis testing, power was computed at the Bonferroni-adjusted significance level of 0.05/403 = 1.2 × 10-4. Under the simplified model, we computed the statistical power to detect causal SNPs for our sample and study design for the sample FEI prevalences, denoted by Kp, for Whites (22.5%) and Blacks (45%), across a range of total heritabilities, h2t = 15%, 35%, and 55%, where the lattermost total heritability was observed for FEI liability in the current study (Figure 1). It should be noted that because the liability heritability is known to be biased upward, we applied the Dempster-Lerner correction to both the total and SNP-specific heritabilities.3 Close inspection of Figure 1 reveals that varying h2t from 15% to 35% to 55% results in slight decreases in power due to the decreasing ratio of the SNP-specific heritability to the total heritability. However, as seen in all three panels, the more important determinant of power is clearly the FEI prevalence in that the power curve for a Kp of 45% is associated with greater power than the power curve for a Kp of 22.5% across the range of total heritabilities examined. As seen in Figure 1, we have adequate power to detect SNP heritabilities as low as 5% and 6%, respectively, for a Kp of 45% and 22.5%. As noted above, we observed a FEI liability total heritability of 55% consisting of a 47% residual additive genetic heritability (p = 0.019) and 8% F8-mutation specific heritability (p = 0.005). This is the first study to use a GRM based on genotype data and a shared causal F8 mutation matrix to model additive genetic and F8-mutation specific effects.Almeida M, Peralta J, Farook V, …, Blangero J. Pedigree-based random effect tests to screen gene pathways. BMC Proc. 2014; 8(Suppl 1 Genetic Analysis Workshop): S100.Blangero J, Diego VP, Dyer T, …, Göring H. A kernel of truth: statistical advances in polygenic variance component models for complex human pedigrees. Adv Genetics. 2013; 81: 1-31.Glahn D, Williams J, McKay D, …, Blangero J. Discovering schizophrenia endophenotypes in randomly ascertained pedigrees. Biol Psychiatry. 2015; 77(1): 75-83. Disclosures Chitlur: Baxter, Bayer, Biogen Idec, and Pfizer: Honoraria; Novo Nordisk Inc: Consultancy. Dinh:Haplomics Biotechnology Corporation: Employment, Equity Ownership. Howard:Haplomics Biotechnology Corporation: Equity Ownership, Other: Chief Scientific Officer, Patents & Royalties: Patent applications and provisional patent applications ; CSL Behring: Research Funding.
37
Veatch-Blohm, Maren E., Dennis T. Ray, and Valerie H. Teetor. "(272) An Alternative Method for Estimating Heritability in Facultative Apomictic Guayule." HortScience 41, no. 4 (July 2006): 1028B—1028. http://dx.doi.org/10.21273/hortsci.41.4.1028b.
Full textAbstract:
Guayule (Parthenium argentatum Gray) has been difficult to improve through classical plant breeding because of its facultative apomictic reproductive system. Attempts have been made to increase rubber concentration and yield by examining traits correlated with rubber production and their heritabilities. We propose a new way of estimating heritability in guayule that more accurately accounts for the contributions of apomictic and sexual reproduction. At two years of growth, there was a significant relationship between the parents and the progeny for all traits measured, except for rubber and guayulin B concentrations. Due to the facultative apomictic nature of guayule reproduction, heritabilities are more accurately presented as a range of values between the narrow and broad sense heritabilities. Since guayule is more apomictic than sexual, most heritabilities will be closer to the broad sense values. To increase resin and rubber yield in the progeny, selection should focus on height and width in the parents because height and width are highly correlated with rubber yield, with the highest heritabilities (0.65 to 1.00 and 0.97 to 1.0, respectively) of the traits measured.
38
Marks, Gary N. "The Contribution of Genes and the Environment to Educational and Socioeconomic Attainments in Australia." Twin Research and Human Genetics 20, no. 4 (June 13, 2017): 281–89. http://dx.doi.org/10.1017/thg.2017.32.
Full textAbstract:
This article analyzes the contribution of genetics and the environment to educational attainment, occupational status, and income using data from over 1,100 monozygotic and 400 dizygotic Australian twin pairs aged from 18 to 99. The respective heritability estimates were 0.54, 0.37, and 0.18. The bivariate heritabilities were 0.71 for educational attainment and occupational status, 0.37 for education and income, and 0.61 for occupational status and income. There were no gender and cohort differences in the heritabilities for education and occupation, but for income, contrary to expectations, the heritabilities were significantly higher among women and for the older cohort (aged 50 or older). The sizable contribution of genes to these socioeconomic outcomes suggests that standard sociological and economic theories on the socioeconomic career require substantial modification to accommodate the role of genetics.
39
Sularto, Sularto, Rita Febrianti, and Suharyanto Suharyanto. "ESTIMASI HERITABILITAS DAN RESPONS SELEKSI PERSILANGAN IKAN GURAMI (Osphronemus goramy Lac.)." Jurnal Riset Akuakultur 11, no. 1 (November 14, 2016): 23. http://dx.doi.org/10.15578/jra.11.1.2016.23-28.
Full textAbstract:
Ikan gurami (Osphronemus goramy Lac.) dikenal sebagai ikan yang lambat tumbuh. Perbaikan mutu genetik dapat dilakukan untuk mengatasi kendala tersebut, salah satunya adalah melalui program seleksi. Pembentukan populasi dasar dengan menggabungkan persilangan empat populasi Kalimantan, Jambi, Majalengka (M), dan Tasikmalaya dilakukan untuk meningkatkan keragaman genetik. Tujuan penelitian ini untuk mengestimasi nilai heritabilitas dan respons seleksi karakter pertumbuhan bobot ikan gurami hasil persilangan empat populasi gurami sebagai populasi dasar. Persilangan dilakukan dengan rasio jantan: betina (1:1) dan terbentuk 12 famili. Seleksi dilakukan menggunakan metode seleksi famili berdasarkan karakter bobot. Parameter yang diamati adalah karakter pertumbuhan bobot. Data yang digunakan untuk perhitungan etimasi heritabilitas dan respons seleksi adalah data bobot pada umur 11 bulan. Dari data tersebut digunakan untuk menghitung koefisien keragaman (CV), diferensial seleksi (S), estimasi nilai heritabilitas (h2), estimasi respons seleksi (R), dan standard error (SE). Hasil penelitian menunjukkan bahwa populasi dasar yang terbentuk memiliki nilai estimasi heritabilitas 0,4991 yang termasuk kategori tinggi, diferensial seleksi sebesar 124,22 g; sehingga mendapatkan nilai estimasi respons seleksi sebesar 62 g atau (18,2%).Giant gourami (Osphronemus goramy Lac.) is known as a slow growing fish. Genetic improvement can be done to overcome this obstacle; one way is through the selection program. Formation of base population by combining cross four populations can increase genetic diversity. The crosses four populations were: Kalimantan (Borneo), Jambi, Majalengka, and Tasikmalaya. The purpose of this study was to estimate the heritability and response to selection of characters in length and weights of giant gourami from four crosses population as the base population of synthetic material. Crossings were made with the ratio of male: female (1:1) to form 12 families. Selection was made after 11 months old fish. Selection was done using the family selection method based on the body weight character. Observations were conducted on parameter the body weight (BW). The data was used to calculate the coefficient of variance (CV), the selection differential (S), the estimated heritability (h2), the estimated selection response (R), and standard error (SE). The result showed an estimated heritability value was 0.4991 and categorized as high level, amounting to 124.22 g of selection differential, so the estimated selection response value was 62 g (18.2%).
40
Gülcü, S., and A. Ö. Üçler. "Genetic Variation of Anatolian Black Pine (Pinus nigra Arnold. subsp. pallasiana (Lamb.) Holmboe) in the Lakes District of Turkey." Silvae Genetica 57, no. 1-6 (December 1, 2008): 1–5. http://dx.doi.org/10.1515/sg-2008-0001.
Full textAbstract:
Abstract In this study, morphological characteristics of juvenile 1- and 2-year-old seedlings of Anatolian black pine were studied to estimate the amount of genetic variation and heritability of seedling traits of the species in the Lakes District of Turkey. This nursery study involved 460 parent trees from 23 populations in a randomized complete block design. Traits studied were the number and length of cotyledons, hypocotyls and epicotyls lengths, weight and length of initial roots, height, root collar diameter, and stem and root fresh weights, and number of buds. Variation was higher among than within populations with individual tree heritability ranging from 0.09 to 0.76, whereas family mean heritability ranged from 0.16 to 0.80. Genetic and phenotypic correlations between juvenile and 1-year-old seedling traits were generally the same sign and magnitude. Variation and heritabilities were higher for growth-related traits than the number and length of embryonic tissues. The observed level of population differentiation was low, possibly due limited geographic sampling of populations, which spanned only 2° of latitudes and longitudes, and 300m in elevation. If the observed heritabilities for growth traits were sustained to tree maturity combined family and within family selection would be effective in improving growth of this species in the Lakes District of Turkey. A broader geographic sampling is recommended for better estimation of population differentiation and establishment of the geographic pattern of the species in this region.
41
Gebhardt-Henrich, Sabine G., and Henry L. Marks. "Heritabilities of growth curve parameters and age-specific expression of genetic variation under two different feeding regimes in Japanese quail (Coturnix coturnix japonica)." Genetical Research 62, no. 1 (August 1993): 45–55. http://dx.doi.org/10.1017/s0016672300031554.
Full textAbstract:
SummaryThis study investigated genetic variation in growth and final size in relationship to differences in heritabilities under good and poor feeding conditions. Heritabilities of growth and final size were estimated for several traits underad libitumand restricted feeding conditions. A 30% feed restriction from hatching to 44 days of age in Japanese quail chicks decreased body weight and tarsus length at 44 days of age and the length of the third primary covert feather at 24 days of age relative to controls fedad libitum. Wing length at 44 days of age was not significantly different forad libitumfed and restricted quail. Genetic variances for body weight and tarsus length were very large throughout growth which resulted in heritability estimates close to one for these traits. The genetic correlations among feeding treatments were low, indicating that different genes were affecting growth under the two treatments. Growth was described by the components: asymptote, growth period, and shape of the growth curve following the modified Richards growth curve model (Brisbinet al.1986). Tarsus length, which had high heritability of the parameter ‘growth period’ of the model, tended to display a higher heritability under the restriction than underad libitumfeeding. Body weight and feather length, which had either no heritable or low heritable ‘growth periods’ estimates, tended to be more heritable underad libitumfeeding. The shape parameter of the growth curve was not heritable for any trait, except tarsus length under restricted feeding.
42
Hill, J. A., R. W. Ponzoni, and J. W. James. "Micron blowout: heritability and genetic correlations with fibre diameter and secondary follicle diameter." Australian Journal of Agricultural Research 50, no. 8 (1999): 1375. http://dx.doi.org/10.1071/ar98192.
Full textAbstract:
Calculation of micron blowout as the difference between fibre diameter records taken at different ages can produce ‘biased’ estimates of the heritability and genetic correlations due to a scale effect. In some instances, standardisation of the fibre diameter records to a common genetic variance (i.e. removal of the scale effect) changed the heritability and the genetic correlation estimates. The effect of standardisation on the heritability of micron blowout was determined to a large extent by the difference in the genetic variance between the 2 fibre diameter measurements, whereas in the case of the genetic correlation between micron blowout and another trait, it was also dependent on the genetic correlation between the other trait and the two fibre diameters. It is recommended that heritabilities and genetic correlations involving micron blowout be calculated after standardising the fibre diameter measurements to a common genetic variance. The practical implications of the results are briefly discussed.
43
Wierzbicki, H. "Breeding value evaluation in Polish fur animals: Estimates of direct heritability and portion of litter variation of fur coat and reproduction traits." Czech Journal of Animal Science 49, No. 11 (December 13, 2011): 474–82. http://dx.doi.org/10.17221/4334-cjas.
Full textAbstract:
The study presents estimates of heritability for fur coat and reproduction traits in arctic and silver foxes kept on Polish farms. The estimates of variance components were calculated using the DFREML and single-trait animal models. Due to a discrete character of fur coat traits, they were analysed twice: (1) without normalisation of their scores distribution, (2) after the normal probability scale transformation of their scores. Linear models included random additive genetic and common litter environment effects, and fixed effects of farm × year × birth season in the silver fox or year × birth season in the arctic fox as well as the fixed effect of female age when the reproduction traits were analysed. Moreover, the estimation of variance components for fur coat traits was done by a linear model with (Model 2) or without (Model 1) inbreeding coefficients included as linear covariable. In the arctic fox accounting for inbreeding and the data transformation did not markedly influence the estimates of heritability and the portion of litter variation calculated for the fur coat traits. An inbreeding effect was negligible (except for body size – BS) likely due to the low inbred level of the arctic fox population. In the silver fox the comparison of estimates derived using 2 different linear models and 2 data sets revealed more differences than it was found in the arctic fox. Accounting for inbreeding usually led to lower estimates of heritability, mainly when heritabilities were derived from the normal probability scale-transformed data. Most of the estimates of heritability of reproduction traits were found within the range reported by other authors. However, somewhat higher heritabilities were found for litter size at birth – LSB (0.205) and litter size at weaning – LSW (0.250).
44
KENDLER, KENNETH S., and STEVE H. AGGEN. "Time, memory and the heritability of major depression." Psychological Medicine 31, no. 5 (July 2001): 923–28. http://dx.doi.org/10.1017/s0033291701003695.
Full textAbstract:
Objective. Although family, twin and adoption studies have suggested that lifetime major depression (MD) is a heritable condition, nearly all these studies have relied for the diagnosis on long-term human memory, which is fallible and potentially biased. Could the estimates of heritability of MD be biased by the well-demonstrated genetic influences on memory?Methods. Both members of 858 female–female twin pairs from a population-based registry were personally interviewed at least three times over 9 years. The interview assessed a history of depressive onsets and recoveries in the last year to the nearest month. We examine heritability of MD using four recall intervals: last year, last 6 months, last 3 months and current month.Results. Examining the occurrence of one or more depressive episodes across all three interviews, heritabilities of MD (95% CI) for the four time periods were: 0·41 (0·27–0·54), 0·41 (0·26–0·55), 0·35 (0·16–0·52) and 0·34 (0·11–0·55). These heritability estimates did not differ significantly from one another. A similar pattern was found if heritability was assessed for the number of interviews in which criteria for MD were met.Conclusion. Modelling results suggest that the heritability of MD was not influenced by the duration of the required recall. Genetic influences on human recall do not appear to contribute substantially to estimated heritability of MD.
45
Hermida, M., C. Fernández, R. Amaro, and E. San Miguel. "Heritability and "evolvability" of meristic characters in a natural population of Gasterosteus aculeatus." Canadian Journal of Zoology 80, no. 3 (March 1, 2002): 532–41. http://dx.doi.org/10.1139/z02-022.
Full textAbstract:
Phenotypic and genetic variabilities of nine meristic traits (in threespine stickleback, Gasterosteus aculeatus) were calculated for 33 full-sib families raised under controlled laboratory conditions and for 33 pairs caught in nature. Heritabilities were measured using three methods: regression (across environments, laboratorynature), full sib (laboratory), and minimum estimate (nature). Evolvabilities, as an alternative measure of genetic variability, were computed from the genetic coefficient of variation across environments, in the laboratory, and in nature. In general terms, phenotypic variability was smaller in laboratory-reared fish than in wild fish. Results applying both parameters (heritability and evolvability) suggest that in the natural environment, there is a relevant presence of additive genetic variability for lateral-plate number and, to a lesser extent, for lower gill rakers, as well as maternal effects on caudal and abdominal vertebrae and paternal effects on dorsal fin rays. Some of the meristic traits examined are bilateral. Heritabilities across environments and in the laboratory for fluctuating asymmetry values were calculated according to conventional methods and also employing method 2 of Falconer. Qualitatively, the results were almost the same using the two methods: most heritability values were around zero, even taking into account overall measures of fluctuating asymmetry.
46
Emerson, Jennifer L., John Frampton, and Steven E. McKeand. "Genetic Variation in Early Growth and Bud Production among Natural Populations of Fraser Fir." HortScience 43, no. 3 (June 2008): 661–66. http://dx.doi.org/10.21273/hortsci.43.3.661.
Full textAbstract:
A series of open-pollinated progeny tests of Fraser fir [Abies fraseri (Pursh) Poir.] was analyzed to determine natural variation among six geographic seed sources and to estimate genetic parameters for traits important in Christmas tree production. Highly significant differences were found among seed sources and families within sources (P ≤ 0.0001) for height after 4 years in the field. The individual-tree within-population heritability values for the traits measured in Year 4 ranged from 0 to 0.44, with height having the highest heritability, overall tree quality having a heritability of 0.14, and bud and branching traits having varying heritabilities. Heritability values for height at age 4 varied greatly among the six sources, from 0.15 for the Black Mountains to 0.67 for the Great Smoky Mountains. Highly significant seed source × site interactions as well as family within source × site interactions existed for height. Stability variance analysis, after removing the environmental heterogeneity, showed significant instability across the test sites for two of the six seed sources for height after 4 years, and some rank changes occurred. The high heritability values for height indicate that economically important genetic gains can be made in Fraser fir for Christmas tree production because of the importance of height in determining Christmas tree value.
47
Baltunis, Brian S., Dudley A. Huber, Timothy L. White, Barry Goldfarb, and Henry E. Stelzer. "Genetic effects of rooting loblolly pine stem cuttings from a partial diallel mating design." Canadian Journal of Forest Research 35, no. 5 (May 1, 2005): 1098–108. http://dx.doi.org/10.1139/x05-038.
Full textAbstract:
More than 239 000 stem cuttings from nearly 2200 clones of loblolly pine (Pinus taeda L.) were set in five rooting trials to estimate genetic parameters associated with rooting. Overall rooting success across the five trials was 43%, and significant seasonal effects were observed. Differences among clones within full-sib families accounted for approximately 10%17% of the total variation. On the binary scale, individual-tree narrow-sense heritability (ĥ20.1) ranged from 0.075 to 0.089 for rooting across the five separate settings, while broad-sense heritability (Ĥ20.1) ranged from 0.15 to 0.22. Narrow- and broad-sense heritability estimates on the observed binary scale were transformed to their underlying normal scale (ĥ2N, Ĥ2N). When all of the data from the five trials were analyzed together, ĥ2N (±SE) was 0.081 (0.027), Ĥ2N was 0.16 (0.013), the type B additive correlation was 0.68 (0.23), and the type B dominance correlation was 0.61 (0.27). Narrow-sense family mean heritability was 0.83 (0.24), while broad-sense clonal mean heritability was 0.82 (0.074). These moderate to high family and clonal mean heritabilities, moderate type B correlations, and substantial among-family and among-clone genetic variation indicate the potential for increasing rooting efficiency by selecting good rooting families and clones or culling poor rooters.
48
SAVOIE, YVAN, and FRANCIS MINVIELLE. "ÉTUDE SUR LES PORCS DE RACE CONTRÔLÉS À LA FERME AU QUÉBEC. 2. ESTIMATION DES PARAMÈTRES GÉNÉTIQUES ET PHÉNOTYPIQUES." Canadian Journal of Animal Science 68, no. 4 (December 1, 1988): 1063–68. http://dx.doi.org/10.4141/cjas88-121.
Full textAbstract:
Variance and covariance components were estimated from 94 161 observations of growth and backfat taken on purebred pigs born from 8561 sows and 1431 boars. The mixed model used had herd, year-season, parents' birth years, gender and parity number as fixed effects and sire and dam as random effects. Each breed, Yorkshire, Landrace, Hampshire and Duroc, was studied separately. Several statistical methods of estimation were used but resulting values of heritability were generally quite similar. Heritability of growth traits obtained from MIVQUEO (minimum variance quadratic unbiased estimation) was between 0.21 and 0.40, depending on the breed. Heritability of backfat depth was larger, from 0.49 to 0.77. Genetic correlation of daily gain and backfat varied between 0.08 and 0.56; it was between −0.09 and −0.56 for age at 90 kg and backfat. Corresponding phenotypic correlations were smaller in absolute value but had the same sign as genetic correlations. Key words: Pigs, heritabilities, correlations, backfat, growth, index
49
Li, Ji, Huijuan Liu, Terri H. Beaty, Hua Chen, Benjamin Caballero, and Youfa Wang. "Heritability of Children's Dietary Intakes: A Population-Based Twin Study in China." Twin Research and Human Genetics 19, no. 5 (August 15, 2016): 472–84. http://dx.doi.org/10.1017/thg.2016.61.
Full textAbstract:
Background: Despite evidence for some genetic control of dietary intake in adults, there is little evidence of how genetic factors influence children's dietary patterns. Objective: To estimate heritability of dietary intake in twin children from China and test if genetic effects on dietary intakes vary by the children's socio-economic status (SES). Methods: A sample of 622 twins (162 monozygotic and 149 dizygotic pairs; 298 boys and 324 girls aged 7–15 years) was recruited in South China. Dietary intakes were assessed using a validated 145-item semi-quantitative food frequency questionnaire. Pooled and sex-specific dietary patterns were identified using factor analysis. Heritability was estimated using structural equation models. Results: Heritable components differed by gender and for nutrients and food groups; and estimated heritability of dietary patterns was generally greater in girls than boys. In boys, estimated heritabilities ranged from 18.8% (zinc) to 58.4% (fat) for nutrients; and for food group, 1.1% (Western fast foods) to 65.8% (soft drinks). In girls, these estimates ranged from 5.1% (total energy) to 38.7% (percentage of energy from fat) for nutrients, and 12.6% (eggs) to 94.6% (Western fast foods) for food groups. Factor analysis identified five food patterns: vegetables and fruits, fried and fast foods, beverages, snacks and meats. Maternal education and family income were positively associated with higher heritabilities for intake of meat, fried, and fast food. Conclusions: Genetic influence on dietary intakes differed by gender, nutrients, food groups, and dietary patterns among Chinese twins. Parental SES characteristics modified the estimated genetic influence.
50
Rojas de Oliveira, Hinayah, Henrique Torres Ventura, Edson Vinícius Costa, Mariana Alencar Pereira, Renata Veroneze, Marcio de Souza Duarte, Otávio Henrique Gomes Barbosa Dias de Siqueira, and Fabyano Fonseca e Silva. "Meta-analysis of genetic-parameter estimates for reproduction, growth and carcass traits in Nellore cattle by using a random-effects model." Animal Production Science 58, no. 9 (2018): 1575. http://dx.doi.org/10.1071/an16712.
Full textAbstract:
Meta-analysis based on a random-effects model is used to summarise and overcome the variability between divergent parameter estimates. We proposed a meta-analysis of published heritability and genetic-correlation estimates for reproduction, growth and carcass traits in purebred Nellore cattle. In total, 197 heritability and 107 genetic-correlation estimates from 62 scientific publications were used here. Most of traits (gestation length; weights at birth, 120, 210, 365 and 550 days of age; mature weight and all carcass traits) presented direct heritability estimates ranging from 0.20 to 0.40. Age at first calving presented the lowest value among direct heritabilities (0.1498); whereas the higher values (>0.40) were found for scrotal circumference at different ages and for weight at 450 days of age. Low maternal heritability estimates (ranging from 0.06 to 0.11) were observed for all growth traits. With the exception of correlation estimates involving the age at first calving, all other correlations were positive. High correlations (>0.85) were found mainly for the same trait at different ages. The results reported here will give support to genetic evaluations when reliable estimates for different traits in purebred Nellore cattle are not available.