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Modelling test day data from dairy cattle

100%

Szyda J., Liu Z.

Journal of Applied Genetics

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1999

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tom 40

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nr 2

2

Genetic evaluation of litter size traits in Pannon Large rabbits

86%

Nguyen N. T., Farkas J., Szendro Z., Nagy I.

Animal Science Papers and Reports

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2017

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tom 35

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nr 2

Genetic parameters and genetic trends for the number of kits born alive (NBA), number of kits born dead (NBD) and the total number of born kits were estimated in Pannon Large rabbits. Using the REML method 12 single trait models were examined. Heritability estimates were low for all traits and ranged between 0.07-0.08 (with standard errors 0.018-0.021) for NBA (5830 records), 0.01-0.02 (0.009-0.009) for NBD (6278 records) and 0.04-0.05 (0.015-0.018) for TNB (6278 records) from 1469 does. The ratios of the permanent environmental and the phenotypic variances exceeded of the heritability estimates and ranged between 0.11-0.16(0.016-0.018) for NBA, 0.06-0.07 (0.014-0.015) for NBD and 0.11-0.17 (0.014-0.017) for TNB. When characterizing the goodness of models bias values were practically zero for all traits and models. After identifying the best fitted model (containing parity, age of the doe and year-month of kindling effects) it was extended with dominance effects. As a result, heritability estimates decreased to 0.06 (0.028) for NBA, 0.02 (0.012) for NBD and 0.02 (0.022) for TNB. The relative importance of the permanent environmental effects also decreased to 0.09 (0.031) for NBA, 0.05 (0.024) for NBD and 0.07 (0.028) for TNB. Ratios of the dominance effects exceeded those of the heritability estimates and amounted to 0.27 (0.024) for NBA, 0.05 (0.013) for NBD and 0.38 (0.025) for TNB. When compared to the additive model, the model including dominance showed some confounding with additive genetic and with permanent environmental effects and reduced calculated genetics trends (0.035 vs 0.03, -0.0017 vs -0.003 and 0.016 vs 0.01 for NBA, NBD and TNB, respectively). Spearman rank correlation coefficients between breeding values of the additive and dominance models were high for all traits (0.96-0.98). When dominance effects were included some re-ranking was observed among the top ranked animals for every trait.

3

Joint genetic evaluation of Nordic dairy cattle

86%

Stranden I., Lidauer M., Poso J., Mantysaari E. A.

Animal Science Papers and Reports. Supplement

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2004

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tom 22

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nr 2

4

Evaluation of genetic diversity of local-colored rice landraces using SSR markers

72%

Thi Hue H., Nghia L. T., Minh H. T., Anh L. H., Thi Thu Trang L., Khanh T. D.

International Letters of Natural Sciences

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2018

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tom 67

Analysis of genetic diversity of 90 Vietnamese local-colored rice accessions was carried out using 40 SSR markers. The numbers of polymorphic alleles ranged from 3 to 12 alleles per locus and average of 7.1 alleles per locus. The similarity coefficients of the rice landraces fluctuated from 0.76 to 0.93; at a genetic correlation level of 0.78. Ninety accessions of rice landraces were divided into five groups based on analysis of genetic relationships. The results have indicated that 11 markers included M250, RM302, RM10926, RM208, RM227, RM17231, RM23251, RM5647, RM1376, RM339 and RM228 which gave the unique allele. These markers can be used effectively for genetic diversity of colored rice and provided a specific database and useful materials for landraces identification, local germplasm conservation for further colored rice improvement on rice quality via rice breeding programs in Vietnam.

5

Adjustments for heterogenous herd-year variances in a random regression model for genetic evaluations of Polish Black-and-White cattle

72%

Strabel T., Jankowski T., Jamrozik J.

Journal of Applied Genetics

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2006

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tom 47

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nr 2

The study investigated the existence of heterogeneous variance in first-lactation daily milk yield of Polish Black-and-White cows across herds in different years. Bayesian Information Criterion was used to show that the model with unequal residual variances for different herd-years was more plausible than the model assuming equal variances. A method of adjusting phenotypic records was developed to account for unequal variability in herd-years. Factors used for the data adjustment considered variation of general residuals and residuals for specific herd-years. The size of herd-year was also taken into account. Varied power of corrections was used to analyze the effect of adjustment on estimated breeding values. The method was applied to daily milk records of 817 165 primiparous cows. The effectiveness of the data adjustment was evaluated by the analysis of differences between each bull’s breeding value and its parental index. Data correction reduced the average difference and variance of differences between breeding values and parental indices. Accounting for the size of herd-year classes in correction factors improved the efficiency of heterogeneous variance adjustment.

6

Maternal genetic additive variability of conformation traits in half-bred horses

72%

Torzynski G., Szwaczkowski T.

Electronic Journal of Polish Agricultural Universities. Series Animal Husbandry

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1999

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tom 02

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nr 2

Direct and maternal additive genetic variances as well as covariances between these effects were estimated via derivative-free restricted maximum likelihood algorithm under an animal model. 2750 half-bred mares from four Studs were recorded. The following three traits were analysed: height of wither, circumference of chest, circumference of canon. The breed group, year of birth and place of birth were included as fixed effects. The computations were performed using two genetic models (with and without maternal effects). Direct additive heritability estimates were 0.539 for height of wither, 0.345 (and 0.442 from maternal model) for circumference of chest and 0.233 for circumference of cannon. Using the likelihood ratio test it was concluded that the maternal effects were significiant for the analysed traits. Generally, negative correlation estimates between direct and maternal genetic effects were found for single traits.

7

Cytological and genetic evaluation of anther culture-derived doubled haploids in barley

72%

Szarejko I., Falk D. E., Janusz A., Nabialkowska D.

Journal of Applied Genetics

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1997

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tom 38

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nr 4

Gametoclonal variation among anther culture-derived plants of three barley genotypes was estimated on the basis of cytological analysis (DH1, DH2 generation), observation of morphological variants (DH2, DH3) and chlorophyll mutation test (DH2, DH3). Individual head rows were grown in the field to detect possible chimeric structure of regenerants and to assess the number of variants and mutations in each line. Spontaneously doubled plants were the most frequent class (70%) among regenerants and almost 90% of them were completely fertile. There was a difference in proportion of haploids produced by different genotypes, but the highest frequency observed did not exceed 21%. The remaining regenerants were tetraploid, and contained chromosomal mutations or chimeras. In total, there were about 15% of polyploids and plants carrying chromosomal aberrations (translocations, inversions) among DH1 individuals. The changes in chromosome number and structure were the main source of observed variation. The level of gene mutation induced in vitro was relatively low. No more than 1% of microspore-derived plants expressed visible morphological changes in DH2 progeny. Only two morphological variants derived from the Bruce cultivar proved to be homozygous mutants (dwarf type) stable up the to third generation. The frequency of DH plants carrying chlorophyll mutation was 5.8%, but most of them (82%) were chimeric and had only a small mutation sector. The level of gametoclonal variation depended on the donor plant genotype. The highest proportion of variants and mutations was observed among DH plants derived from the Bruce cultivar, while the lowest was recorded among plants regenerated from anther culture of the doubled haploid line H930-36. Mechanisms leading to the observed variation and implications resulting from the presented experiments concerning implementation of anther culture in barley breeding were discussed. It was concluded that this method resulted in a high frequency of spontaneous doubling, a low frequency of genetic changes, and being less time and effort-consuming than the ’Bulbosum’ technique, can be applied to most barley breeding programs.

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Normalization of showjumping competition's results

58%

Schubertova Z., Candrak J.

Annals of Animal Science

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2014

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tom 14

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nr 2

9

Evaluation of genetic variability within sweet cherry (Prunus avium L.) genetic resources by molecular SSR marker

58%

Patrzak J., Henychova A., Paprstein F., Sedlak J.

Acta Scientiarum Polonorum. Hortorum Cultus

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2019

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tom 18

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nr 3

Sweet cherry is a vegetatively propagated, perennial plant with high level of heterozygosity and ancient breeding history. Therefore, it is necessary to keep, conserve and evaluate known genetic resources for future breeding programs and fruit production stability. In present, the utilization of DNA molecular genetic analyses is the best suitable method for evaluation of individual accessions, thus we eliminated duplications and characterized the genetic relationships. In our work, we used PCR primer combinations for 19 SSR and 2 EST-SSR loci for analyses of 123 current, old and local sweet cherry cultivars from Czech genetic resources of Research and Breeding Institute of Pomology in Holovousy. In total, 115 polymorphic fragments were amplified, which we used for hierarchical cluster analysis of genetic variability. The result dendrograms were divided into three main clusters and ten subgroups. Clustering corresponded to genealogical and geobotanical characteristics of individual accessions as breeding history of several known accessions.

10

The selection index and single-and multi-trait animal model evaluation of Polish Black-and-White cows

58%

Jagusiak W., Zarnecki A.

Journal of Applied Genetics

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2000

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tom 41

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nr 3

Ograniczanie wyników

Modelling test day data from dairy cattle

Genetic evaluation of litter size traits in Pannon Large rabbits

Joint genetic evaluation of Nordic dairy cattle

Evaluation of genetic diversity of local-colored rice landraces using SSR markers

Adjustments for heterogenous herd-year variances in a random regression model for genetic evaluations of Polish Black-and-White cattle

Maternal genetic additive variability of conformation traits in half-bred horses

Cytological and genetic evaluation of anther culture-derived doubled haploids in barley

Normalization of showjumping competition's results

Evaluation of genetic variability within sweet cherry (Prunus avium L.) genetic resources by molecular SSR marker

The selection index and single-and multi-trait animal model evaluation of Polish Black-and-White cows