Selection on phenotypic variation of pupa weight in Tribolium castaneum

1986 ◽  
Vol 28 (5) ◽  
pp. 856-861 ◽  
Author(s):  
Sylvie Cardin ◽  
Francis Minvielle
Keyword(s):  
Inbreeding Depression ◽  
Tribolium Castaneum ◽  
Coefficient Of Variation ◽  
Phenotypic Variability ◽  
The Other ◽  
Direct Selection ◽  
Phenotypic Variance ◽  
Realized Heritability ◽  
Coefficients Of Variation ◽  
Selection For

Responses to selection for high and low intrafamily coefficients of variation of pupa weight in Tribolium castaneum were observed for 10 generations. A significant decrease of the coefficient of variation has been observed in the replicated lines selected downwards while no response occurred in the other lines. Mean pupa weights did not change significantly throughout the experiment while mean fertility decreased in all lines, probably as a consequence of inbreeding depression. Realized heritability of the coefficient of variation of pupa weight was 0.15 ± 0.04 and 0.03 ± 0.01% for the downwards and upwards lines, respectively. These results show that the manipulation of the phenotypic variability by direct selection is possible.Key words: Tribolium, phenotypic variance, coefficient of variation of pupa weight.

Gas Chromatographic Methods for Determination of γ-BHC in Technical Emulsifiable Concentrates and Water-Dispersible Powder Formulations and in Lindane Shampoo and Lotion: Collaborative Study

1984 ◽  
Vol 67 (4) ◽  
pp. 834-837
Author(s):  
James W Miles ◽  
Dwight L Mount ◽  
◽  
T J Beckmann ◽  
S K Carrigan ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Internal Standard ◽  
The Other ◽  
Water Dispersible ◽  
Coefficients Of Variation ◽  
Aoac Method ◽  
Liquid Chromatographic ◽  
Gas Chromatographic Separation

Abstract Although the gas chromatographic separation of the isomers of BHC was demonstrated two decades ago, the present AOAC method of analysis of BHC for gamma-isomer (lindane) content is based on a separation carried out on a liquid chromatographic partition column. A method of analysis has been developed that uses an OV-210 column for separation of the gamma-isomer from the other isomers and impurities in technical BHC. Di-n-propyl phthalate was chosen as an internal standard. The same system allows quantitation of lindane in lotion and shampoo after these products are extracted with ethyl acetate-isooctane (1 + 4). The analytical methods were subjected to a collaborative trial with 10 laboratories. The coefficient of variation for technical BHC was 2.83%. For the water-dispersible powder and emulsifiable concentrate, the coefficients of variation were 2.89% and 4.62%, respectively. Coefficients of variation for 1% lindane lotion and shampoo were 4.36% and 11.92%, respectively. The method has been adopted official first action.

THREE GENERATIONS OF INBREEDING AND S2 FACTORIAL TEST CROSSES IN RED RASPBERRY CULTIVARS

1974 ◽  
Vol 16 (2) ◽  
pp. 419-432 ◽  
Author(s):  
S. O. Fejer ◽  
L. P. S. Spangelo
Keyword(s):  
Plant Height ◽  
Inbreeding Depression ◽  
Breeding Program ◽  
High Yield ◽  
Realized Heritability ◽  
Red Raspberry ◽  
Diallel Crosses ◽  
Berry Quality ◽  
Selection For ◽  
Early Vigor

In selfed (S1 to 33) progenies of red raspberry cultivars, inbreeding depression progressively reduced plant height in spite of selection for vigor. Parent-offspring correlations indicated high realized heritability of this character. High yield was correlated in this material with many laterals, early flowering, tall new canes, and good berry quality but not with winter resistance. Heritability in the broad sense was high for early vigor, plant height and winter resistance, lower for berry weight and flowering day, and very low for yield and its morphological components, but selection for vigor may have influenced these estimates.In a second experiment five S2 progenies and their parent cultivars Muskoka, Trent and Tweed were crossed with three tester plants, Ottawa Latham, Viking and 45-01-56. Some of the S2 × tester progenies were superior in a number of yield characters to those produced when their parent cultivar was crossed to the same testers. The results were similar to those with strawberry (Spangelo et al., 1971), suggesting that inbreeding may sometimes be a useful step in a raspberry breeding program for higher yield. However, inbred × inbred crosses were generally poor. General and specific combining abilities were mostly similar in three different samples of factorial ("¼ diallel") crosses, but there were many exceptions possibly due to genotype-environment interactions. Most of the correlations were significant in this trial and the highest ones were in agreement with the correlations in the inbreeding trial.

scholarly journals Comparing evolvability and variability of quantitative traits.

Genetics ◽  
1992 ◽  
Vol 130 (1) ◽  
pp. 195-204 ◽  
Author(s):  
D Houle
Keyword(s):  
Coefficient Of Variation ◽  
Stabilizing Selection ◽  
Phenotypic Variance ◽  
Weak Selection ◽  
Residual Variation ◽  
Coefficients Of Variation ◽  
Genetic Coefficient Of Variation ◽  
Environmental Events ◽  
Genetic Coefficient ◽  
Comparative Measure

Abstract There are two distinct reasons for making comparisons of genetic variation for quantitative characters. The first is to compare evolvabilities, or ability to respond to selection, and the second is to make inferences about the forces that maintain genetic variability. Measures of variation that are standardized by the trait mean, such as the additive genetic coefficient of variation, are appropriate for both purposes. Variation has usually been compared as narrow sense heritabilities, but this is almost always an inappropriate comparative measure of evolvability and variability. Coefficients of variation were calculated from 842 estimates of trait means, variances and heritabilities in the literature. Traits closely related to fitness have higher additive genetic and nongenetic variability by the coefficient of variation criterion than characters under weak selection. This is the reverse of the accepted conclusion based on comparisons of heritability. The low heritability of fitness components is best explained by their high residual variation. The high additive genetic and residual variability of fitness traits might be explained by the great number of genetic and environmental events they are affected by, or by a lack of stabilizing selection to reduce their phenotypic variance. Over one-third of the quantitative genetics papers reviewed did not report trait means or variances. Researchers should always report these statistics, so that measures of variation appropriate to a variety of situations may be calculated.

scholarly journals Genetic variability analysis for various yield attributing traits in rice genotypes

2017 ◽  
Vol 15 (1) ◽  
pp. 15-19
Author(s):  
MM Rashid ◽  
M Nuruzzaman ◽  
L Hassan ◽  
SN Begum
Keyword(s):  
Genetic Variability ◽  
Coefficient Of Variation ◽  
Block Design ◽  
Direct Selection ◽  
Genetic Advance ◽  
Randomized Complete Block Design ◽  
Additive Gene ◽  
High Heritability ◽  
Rice Genotypes ◽  
Selection For

An experiment was conducted using a randomized complete block design to estimate genetic variability of ten rice genotypes. Analysis of variance for yield and yield contributing traits showed significant (p<0.01) variation among the genotypes. Results of genetic analyses showed a higher phenotypic coefficient of variation compared to their corresponding genotypic coefficient of variation for all the traits measured, which indicates that the traits were influenced by environment. The magnitude of difference between phenotypic coefficient of variance (PCV) and genotypic coefficient of variance (GCV) was less for the traits indicating little influence of environment. The higher estimates of PCV and GCV were observed for number of filled grains panicle–1 (27.53; 26.84), number of unfilled grains panicle–1 (26.76;25.28) and plant height (23.14; 23.00) indicates possibility of genetic improvement through direct selection for these traits, while days to 50% flowering, days to maturity, panicle length, number of effective tillers plant–1, fertility (%), 1000 Seed weight and yield panicle–1 showed low PCV and GCV values indicating the need for creation of variability by hybridization or mutation followed by selection. High heritability values (>60%) along with high genetic advance and genetic advance as percentage of mean were found for all the traits indicating prevalence of additive gene action, which provides good scope for further improvement by selection.J. Bangladesh Agril. Univ. 15(1): 15-19, January 2017

A note on the improvement of a trait by selecting on its components

1967 ◽  
Vol 9 (1) ◽  
pp. 127-130 ◽  
Author(s):  
Charles Smith
Keyword(s):  
Litter Size ◽  
Coefficient Of Variation ◽  
Farm Animals ◽  
Direct Selection ◽  
Component Trait ◽  
Component Traits ◽  
Selection For ◽  
Fleece Weight

Many traits in farm animals, such as litter size or fleece weight, are the product or ratio of two or more component items. This note seeks to determine the circumstances in which selection directed at the component items is more effective in improvement than selection for the composite trait itself.A change of one per cent in a product trait can be achieved by a change of one per cent in any of its components. The response expected on selection for a product trait or a component is proportional to h2C per cent, where h2 is the heritability and C is the coefficient of variation. Thus selection for a component trait (A) may possibly be more efficient than direct selection for the product trait (X) when is greater than . However, the correlated changes in other component traits would also have to be taken into account.

scholarly journals Long-term selection for protein amount over 70 generations in mice

1998 ◽  
Vol 72 (2) ◽  
pp. 93-109 ◽  
Author(s):  
LUTZ BÜNGER ◽  
ULLA RENNE ◽  
GERHARD DIETL ◽  
SIEGFRIED KUHLA
Keyword(s):  
Body Weight ◽  
Selection Response ◽  
Direct Selection ◽  
Control Line ◽  
Phenotypic Variance ◽  
Effective Population ◽  
Term Selection ◽  
General Importance ◽  
Selection For

Based on the outbred mouse strain Fzt: Du, which has been obtained by systematic crossing of four inbred and four outbred lines, a long-term selection experiment was carried out for total protein amount (PA) in the carcass, starting in 1975. An unselected control line (CO) was kept under the same management but without continuous protein analysis. The protein amount of male carcasses at 42 days of age (P42) increased from 2·9 g in generation 0 to 5·2 g at generation 70, representing 97% of a theoretical selection limit. The total selection response amounts to 2·3 g, which is about 80% above the initial value and corresponds to 9σp or 12σA . The estimated realized heritability of protein amount decreased from 0·56 to 0·03 at generation 70, which was due to an increase in phenotypic variance from 0·065 to 0·24 g2 and a reduction in genetic variance from 0·04 to 0·01 g2. Half the selection response was obtained after about 18 to 23 generations, a half-life of 0·25 to 0·3 Ne. The maximum selection response was 0·094 g/generation and the response was 0·01 g/generation at generation 70. The measurements of body weights at 0, 10, 21, 42 and 63 days throughout the experiment showed a strong correlated effect for all weights. The PA mice are one of the heaviest lines of mice ever reported, and do not differ significantly in their body composition from control mice at 42 days. The direct selection response was due primarily to increased general growth. Body weight and protein amount are phenotypically and genetically highly correlated (rp=0·82, rA≈1); however, selection for body weight led to fatter animals, whereas selection for protein opposed increased fatness (at least until selection age). This may be of general importance in animal breeding. The comparatively high selection response in this experiment seems due to the heterogeneity of the base population, the relatively high effective population size, and the duration of the experiment.

scholarly journals Genetic Variability And Selection Response To Heat Tolerance Through Membrane Thermostability In Spring Wheat (Triticum Aestivum L)

1970 ◽  
Vol 23 (2) ◽  
pp. 15-22
Author(s):  
NCD Barma ◽  
MA Islam ◽  
MA Hakim ◽  
DKR Sarker
Keyword(s):  
Genetic Variability ◽  
Heat Tolerance ◽  
Selection Response ◽  
Research Centre ◽  
Direct Selection ◽  
Realized Heritability ◽  
Response To Selection ◽  
Early Generation ◽  
Membrane Thermostability ◽  
Selection For

The present investigation was undertaken to study the genetic variability and selection response of heat tolerance measured through membrane thermostability (MTS) in F2 derived F4 and F5 generations of five wheat crosses: Kanchan × Gourab, Gourab × Fang 60, Kanchan × Pavon 76, Gourab × Pavon76 and Fang 60 × Pavon76. Each cross was consisted of 65, 60, 77, 72 and 64 F4 bulks including two parents. The study was conducted both in the field and laboratory of Wheat Research Centre, Dinajpur during 2002-03 and 2003-04. A completely randomized design for laboratory experiment and randomized complete block design for field experiments was followed with three replications. Acquired thermal tolerance through Membrane Thermo-stability assay was performed in controlled environment as per method described by Ibrahim and Quick (2001). Other morpho-physiological traits were measured from field experiment. The crosses Kanchan × Gourab, Kanchan × Pavon 76 and Fang 60 × Pavon76 showed high genetic variability with high population mean for MTS in F4 bulks. These crosses also exhibited high-observed response to selection, realized heritability and heritability in standard unit indicating expected good gain through early generation selection. Direct response to selection for this trait was significant in these crosses in F5 generation. Direct selection for MTS significantly improved biomass, grain yield, thousand grain weight, grain filling rate and canopy temperature depression in crosses Kanchan × Pavon 76, Gourab × Pavon76 and Fang 60 × Pavon76 with few exceptions. Direct selection of MTS also improved chlorophyll retention at 21 days after anthesis in crosses Gourab × Fang 60 and Gourab × Pavon76. Significant intergeneration correlations (F4 vs. F5) were observed for MTS in all five crosses studied indicating possibility of effective improvement of this trait through selection in early generation.   Key words: Membrane thermostability; selection response; realized heritability; intergeneration correlation.DOI: http://dx.doi.org/10.3329/bjpbg.v23i2.9320 Bangladesh J. Pl. Breed. Genet., 23(2): 15-22, 2010

Stability and inheritance of storage-induced hardening in 20 common bean cultivars

1991 ◽  
Vol 71 (3) ◽  
pp. 641-647 ◽  
Author(s):  
T. E. Michaels ◽  
D. W. Stanley
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Coefficient Of Variation ◽  
High Standard ◽  
Phenotypic Variance ◽  
Environment Interaction ◽  
Phaseolus Vulgaris L ◽  
Mean Values ◽  
Coefficients Of Variation ◽  
The Stability

Storage of common bean (Phaseolus vulgaris L.) in elevated temperature and/or humidity conditions leads to a textural defect where the beans harden and fail to soften upon soaking and cooking. The objectives of this study were to determine the stability of 20 common bean cultivars grown in three environments for initial hardness, final hardness following storage and hardening ratio, and to estimate the heritability of these hardening parameters. Cultivar × environment interaction was highly significant for the hardening parameters. When stability was examined by plotting hardness against coefficient of variation across environments, three cultivars, GN-77135B, ICA Pijao and T39 Black Turtle, were marginally below the mean for both final hardness and coefficient of variation. While the coefficients of variation for the red kidney bean cultivars Redkloud and Montcalm were high, the maximum compression forces were only slightly (< 20%) greater than the maximum acceptable hardness level as determined by a sensory panel. Fiesta Pinto had the lowest coefficient of variation and near mean values for both final hardness and hardening ratio making it arguably the cultivar with best combination of texture and stability. Heritability estimates were low (0–0.24) with high standard error and estimates of the proportion of phenotypic variance due to G × E were moderate to high (0.29–0.69). Initial cultivar improvement efforts should focus on developing cultivars with greater stability across environments for the hardening parameters. Key words: Phaseolus vulgaris L., storage-induced hardening, stability, broad sense heritability, bean (common)

scholarly journals Genotype × environment interaction in Tribolium castaneum

1964 ◽  
Vol 5 (3) ◽  
pp. 335-340 ◽  
Author(s):  
J. F. Kidwell ◽  
A. E. Freeman ◽  
L. H. Haverland ◽  
G. M. H. Rolfes
Keyword(s):  
Relative Humidity ◽  
Tribolium Castaneum ◽  
Total Variance ◽  
Direct Selection ◽  
Environment Interaction ◽  
Breeding Values ◽  
Genotype Environment Interaction ◽  
The Mean ◽  
Selection For ◽  
C 30

An experiment was conducted with the flour beetle, Tribolium castaneum to investigate genotype-environment interaction. Ninety-two matings of one male and three females were made at random from a large panmictic population. The females were transferred to individual containers after 4 days. Six daughters were randomly selected from each sire–dam pair and individually mated to unrelated males. Three of the six were placed in an incubator (33·3°C., 45% relative humidity) and three in a cabinet at room conditions (22·2–26·7°C., 30–35% relative humidity) and allowed to produce eggs during a 3-day period. Progeny were counted as pupae and larvae. The traits studied were number of pupae and number of pupae plus number of larvae. A transformation to (X +1)½ was required. A conventional least-squares model was employed, and a large environmental effect was observed. In the incubator the mean number of pupae was 13·4 and of pupae + larvae was 20·1 while the corresponding figures for room conditions were 3·3 and 9·2. Genotype-environment interaction accounted for 3·7 to 6·7% of the total variance for (pupae + 1)½ and 2·1 to 8·3% for (pupae + larvae+ 1)½. Heritability of the traits was essentially the same in both environments. The interaction was due to an increasing difference between environments in production associated with increasing breeding values of the sire, and to small changes in rank of breeding values on the two environments. As a result of the interaction, selection in one environment for production on the other would be expected to be only 71 to 72% as effective as direct selection for (pupae + 1)½ and 62 to 86% for (pupae + larvae + 1)½ even though the fraction of the total variance attributed to genotype-environmental interaction was less than 10%.

The effects of alternated cycles of full-sib and random mating on selection for pupa weight in Tribolium castaneum

1985 ◽  
Vol 27 (2) ◽  
pp. 251-254 ◽  
Author(s):  
Nicole Dion ◽  
Francis Minvielle
Keyword(s):  
Mating System ◽  
Tribolium Castaneum ◽  
Random Mating ◽  
Selection Response ◽  
Inbred Lines ◽  
Pupal Weight ◽  
Realized Heritability ◽  
Differential Selection ◽  
Selection For

Individual responses to selection for high pupal weight in Tribolium castaneum under two types of mating, cyclic full-sib random-mating system and random mating, were observed for 15 generations. No significant differences have been observed between the two types of mating for the selection response, differential selection, realized heritability, and the number of larvae per generation. Realized heritability of the pupal weight was 0.33 ± 0.02 and 0.42 ± 0.02 for the inbred lines and for the random-mated lines, respectively.Key words: inbreeding, pupa weight, Tribolium.

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