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1

Milk trait heritability and correlation with heterozygosity in yak

100%

Jiang X. P., Liu G. G., Wang C., Mao Y. J., Xiong Y. Z.

Journal of Applied Genetics

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2004

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vol. 45

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issue 2

215-224

EN

382 yak cows were examined for milk yield, fat, protein and lactose contents. Six polymorphic loci, s1-CN, -CN, -CN, -Lg, -La and MUC-1, were scored by PAGE electrophoresis for each individual. The values of milk yield, fat, protein and lactose content were 247.13 kg, 5.81%, 5.18% and 4.93%, respectively. Based on the 6 polymorphism loci, the average heterozygosity of the yak population was 0.1794. Calculated by the marker-based method, heritability estimates for milk yield, fat, protein and lactose contents were 0.353 ? 0.093, 0.316 ? 0.101, 0.415 ? 0.098 and 0.481 ? 0.035, respectively. The relatively high or medium heritability of these traits indicate that it is feasible to rely directly on them in breeding for the improvement in a relatively short period. The significant linear regression between heterozygosity and fat percentage with a positive slope (R = 0.0420) indicated that inbreeding affected milk fat content in this population.

2

Estimation of genetic parameters for monthly egg production in laying hens based on random regression models

100%

Wolc A., Szwaczkowski T.

Journal of Applied Genetics

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2009

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vol. 50

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issue 1

41-46

EN

. Heritability and genetic correlations of monthly egg production under random regression models were estimated. Three layer lines (A22, A88, K66) in six consecutive generations were analysed. A22 (13,770 recorded hens) and A88 (13,950 recorded hens) are maternal lines of Rhode Island White birds selected on egg production and shell colour; K66 (9,351 recorded birds) is a paternal line of Rhode Island Red birds selected on egg weight. Eight models with different orders of Legendre polynomials were applied. Adequacy of the models was checked by the Akaike Information Criterion. According to the most adequate model including second order Legendre polynomials for fixed effects and third order for additive genetic and permanent environmental effects, relatively high heritabilities were estimated in the first (h2=0.3) and final (h2 above 0.3) periods of production with a substantial decrease in heritability during the egg production peak. Methodology based on random regression animal models can be recommended for genetic evaluation of laying hens.

3

The effect of selection for traits of low heritability conducted in noninbred populations on the basis of progeny or performance tests

100%

Sobczynska M., Kownacki M.

Journal of Applied Genetics

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1995

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vol. 36

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issue 2

169-175

EN

The ivestigations were carried out to compare selection conducted on the basis of progeny with that on the basis of animals' own performance.Selection was conducted for the body weight at weaning (at the age of 21 days), which is a trait of low heritability.It was run throghout 15 generations,whereas in generation 13 and 14 three experimental replices were crossed to obtain population free of inbreeding.A cumulated response to selection was higher in the group selected on the basis of animals'own performance, but after crossing the replicas it decreased clearly in the both groups.The cumulated selection differential was higher in the group selected on the basis of animals'own performance.However, a statistical analysis of the obtained results showed no significant difference between the two selection method.

4

Correlations and heritability of the characters determining the seed yield of the long-raceme alfalfa (Medicago sativa L.)

88%

Bodzon Z.

Journal of Applied Genetics

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2004

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vol. 45

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issue 1

49-59

EN

Phenotypic correlation coefficients and heritability of the characters controlling seed yield of long-raceme forms of alfalfa was determined. It was found that seed yield per plant, which was positively correlated with 10 out of 12 analysed characters, depended upon the number of pods per raceme and the number of seeds per pod. Variability of these characters determined about 60% of the variability of seed yield. Multiple linear regression and phenotypic correlations show that simultaneous selection for increased pod number per raceme and increased seed number per pod and raceme length resulted in enhanced seed yield potential. The share of the additive genetic effects in the phenotypic variance for number of pods per raceme was low and about 21-23%, while for number of seeds per pod and per raceme amounted to about 50%. The expected genetic progress in recombination breeding for number of seeds per pod and number of seeds per raceme will be of medium magnitude, while one cannot expect any rapid and considerable progress in the number of pods per raceme. Considering the high positive correlation between raceme length and number of pods and seeds per raceme, one should conclude that raceme length can be an important criterion in selection of plants showing a high seed productivity.

5

The influence of nutrient shortage on the expression of combining ability effects for root characters in spring barley (Hordeum vulgare L.)

88%

Gorny A. G.

Journal of Applied Genetics

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2000

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vol. 41

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issue 2

63-73

EN

Effects of varied nutrition on the inheritance mode of the total and specific length of roots, root weight, shoot : root ratio and root uptake efficiency were studied in a diallel set of spring barley. Plants were grown in sand-vermiculite cultures under high and low NP nutrition. Results of the analysis of variance indicated that both the general (GCA) and specific (SCA) combining ability effects were important for the total length and dry matter of roots formed at the vegetative growth stage. Preponderance of non-additive gene action and overdominance were apparent only for root dry matter. The specific root length and root uptake efficiencies were controlled by additive gene action. Genotype ? nutrition interactions were significant for the root length measures and uptake efficiency indices. Although significant GCA ? nutrition interaction effects were observed for these root characters, the interactions contributed mostly to the magnitude of GCA effects but not to their sign. Except for root dry matter, the contribution of non-additive gene action to root variation enhanced under stress, heritabilities declined, while degrees of dominance of genes tended to increase. Nevertheless, the moderate narrow-sense heritabilities (18-62%) and the considerable proportion of additive variance found for the root characters under nutrient shortage suggest that an improvement of rooting ability under less favourable nutrition through conventional selection is a real objective for barley breeders.

6

Direct effects of cyclic selection fo longer seminal roots in spring barley (Hordeum vulgare L.)

88%

Gorny A. G.

Journal of Applied Genetics

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1995

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vol. 36

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issue 1

17-26

EN

Cyclic pedigree selection for longer seminal roots was performed in the F2, F3 and F4 generations of hybrid population of spring barley.The total length of roots was measured in seedlings grown in filter-paper rollers.The intensity of selectio was 20% (C1, C2 cycles) and 26% (C3).Selection wasceffective.On anaverage, the finally selected F5-pedigrees formed 6% longer seminal roots system than the initial F2's and much of them exibited 7-16% improved rooting when compared with the best parent in a sand-vermiculite pot culture.Realized heritability coefficient of the root length ranged from 0.21 to 0.37 when assessed by the ratio of selection response to selection differential, while those estimated by the parent-offspring regressions attained 0.40-0.53.The obtained results suggest that progeny evaluation and/or seletion delayed for later generations should be essential for more effective root selection in barley.

7

Genetic determination of variability of barley doubled haploids inoculated with Fusarium culmorum (W.G.Sm.) Sacc. with regard to mycotoxin accumulation and reduction in yield traits

75%

Surma M., Adamski A. T., Adamski T., Chelkowski C. J., Chelkowski J., Golinski G. P., Golinski P., Kaczmarek K. Z., Kaczmarek Z., Kostecki K. M., Kostecki M., Perkowski P. J., Perkowski J., Wisniewska W. H., Wisniewska H.

Journal of Applied Genetics

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2000

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vol. 41

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issue 4

237-246

EN

The genetic determination of variability of barley doubled haploid (DH) lines in regard of their susceptibility to Fusarium head blight caused by Fusarium culmorum was studied. The susceptibility was evaluated in a 3-year field experiment on the basis of reduction in yield traits and mycotoxin accumulation in infected kernels. The following traits were analysed in inoculated and control plants: kernel number and weight per ear, 1000-kernel weight, percentage of plump kernels (>2.5 mm), deoxynivalenol (DON) content and nivalenol (NIV) content of kernels. On the basis of the obtained data, heritability coefficient (ratio of genotypic to phenotypic variance) was assesed, and genetic parameters as well as the number of effective factors were estimated. Heritability coefficients calculated from two-way analysis of variance, i.e. regarding the influence of years and year ? genotype interaction, appeared to be exceptionally low and ranged from 5.2% for the reduction in plump kernels to 38.2% for the reduction in 1000-kernel weight. In the case of mycotoxin accumulation about 60% of the observed variability in NIV concentration and 30% in DON concentration resulted from genetic differences among lines. Additive effects of genes were important for all the analysed traits. Significant effects of dominance and dominance ? dominance were observed for 1000-kernel weight and percentage of plump kernels. Moreover, it was found that the observed variability in yield trait reduction resulted from the segregation of 5-6 effective factors, DON content from 4 factors, while NIV content from 5 factors.

8

Genetic parameters and correlations of collar rot resistance with important biochemical and yield traits in opium poppy (Papaver somniferum L.)

75%

TrivediT., Tiwari R. K., Dhawan O. P.

Journal of Applied Genetics

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2006

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vol. 47

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issue 1

29?38

EN

Collar rot, caused by Rhizoctonia solani Kuhn, is one of the most severe fungal diseases of opium poppy. In this study, heritability, genetic advance and correlation for 10 agronomic, 1 physiological, 3 biochemical and 1 chemical traits with disease severity index (DSI) for collar rot were assessed in 35 accessions of opium poppy. Most of the economically important characters, like seed and capsule straw yield per plant, oil and protein content of seeds, peroxidase activity in leaves, morphine content of capsule straw and DSI for collar rot showed high heritability as well as genetic advance. Highly significant negative correlation between DSI and seed yield clearly shows that as the disease progresses in plants, seed yield declines, chiefly due to premature death of infected plants aswell as low seed and capsule setting in the survived population of susceptible plants. Similarly, a highly significant negative correlation between peroxidase activity and DSI indicated that marker-assisted selection of disease-resistant plants based on high peroxidase activity would be effective and survived susceptible plants could be removed from the population to stop further spread.

9

Bayesian inference of genetic parameters for test-day milk yield, milk quality traits, and somatic cell score in Burlina cows

75%

Penasa M., Cecchinato A., Battagin M., De_ M. M., Pretto D., Cassandro M.

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vol. 51

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issue 4

489-495

EN

The aim of the study was to infer (co)variance components for daily milk yield, fat and protein contents, and somatic cell score (SCS) in Burlina cattle (a local breed in northeast Italy). Data consisted of 13 576 monthly test-day records of 666 cows (parities 1 to 8) collected in 10 herds between 1999 and 2009. Repeatability animal models were implemented using Bayesian methods. Flat priors were assumed for systematic effects of herd test date, days in milk, and parity, as well as for permanent environmental, genetic, and residual effects. On average, Burlina cows produced 17.0 kg of milk per day, with 3.66 and 3.33% of fat and protein, respectively, and 358 000 cells per mL of milk. Marginal posterior medians (highest posterior density of 95%) of heritability were 0.18 (0.09-0.28), 0.28 (0.21-0.36), 0.35 (0.25-0.49), and 0.05 (0.01-0.11) for milk yield, fat content, protein content, and SCS, respectively. Marginal posterior medians of genetic correlations between the traits were low and a 95% Bayesian confidence region included zero, with the exception of the genetic correlation between fat and protein contents. Despite the low number of animals in the population, results suggest that genetic variance for production and quality traits exists in Burlina cattle.

10

The inheritance of plant height in crosses involving short-stem rye genotypes

75%

Izdebski R.

Journal of Applied Genetics

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1995

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vol. 36

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issue 4

325-340

EN

The paper presents results of studies on the inheritance of plant height in four short-stem genotypes of rye selected from genotypically different collection materials.Short-stem genotypes P-2, P-9, P-30 and P-52 were crossed to a tall-stem inbred line Uniwersalne 145 (S17).The genotype P-2 was additionally crossed to a related, but tall-stem line P-2 W.In each cross combnations six generation -P1, P2, F1, F2, B1 (F1 x P10 and B2 (F1 x P2) - were examinaed.Distribution of plant height in hybrid generations haad a continous character, which indicated a polyugenic determination of short stem an all "P" genotypes under study.Results of the genetic analysis showed a significant role of additive, dominance and epistatic gene action in genetic determinatin of short stem in th "P" genotypes.

Refine search results

Milk trait heritability and correlation with heterozygosity in yak

Estimation of genetic parameters for monthly egg production in laying hens based on random regression models

The effect of selection for traits of low heritability conducted in noninbred populations on the basis of progeny or performance tests

Correlations and heritability of the characters determining the seed yield of the long-raceme alfalfa (Medicago sativa L.)

The influence of nutrient shortage on the expression of combining ability effects for root characters in spring barley (Hordeum vulgare L.)

Direct effects of cyclic selection fo longer seminal roots in spring barley (Hordeum vulgare L.)

Genetic determination of variability of barley doubled haploids inoculated with Fusarium culmorum (W.G.Sm.) Sacc. with regard to mycotoxin accumulation and reduction in yield traits

Genetic parameters and correlations of collar rot resistance with important biochemical and yield traits in opium poppy (Papaver somniferum L.)

Bayesian inference of genetic parameters for test-day milk yield, milk quality traits, and somatic cell score in Burlina cows

The inheritance of plant height in crosses involving short-stem rye genotypes