Quantitative Genetics of Ovariole Number in Drosophila melanogaster. II. Mutational Variation and Genotype-Environment Interaction

Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 201-210 ◽  
Author(s):  
Marta L Wayne ◽  
Trudy F C Mackay
Keyword(s):  
Body Size ◽  
Mutation Accumulation ◽  
Stabilizing Selection ◽  
Environment Interaction ◽  
Weak Selection ◽  
Environmental Variance ◽  
Empirical Observation ◽  
Competitive Fitness ◽  
Genotype Environment Interaction ◽  
Ovariole Number

Abstract The rare alleles model of mutation-selection balance (MSB) hypothesis for the maintenance of genetic variation was evaluated for two quantitative traits, ovariole number and body size. Mutational variances (VM) for these traits, estimated from mutation accumulation lines, were 4.75 and 1.97 × 10−4 times the environmental variance (VE), respectively. The mutation accumulation lines were studied in three environments to test for genotype × environment interaction (GEI) of new mutations; significant mutational GEI was found for both traits. Mutations for ovariole number have a quadratic relationship with competitive fitness, suggesting stabilizing selection for the trait; there is no significant correlation between mutations for body size and competitive fitness. Under MSB, the ratio of segregating genetic variance, VG, to mutational variance, VM, estimates the inverse of the selection coefficient against a heterozygote for a new mutation. Estimates of VG/VM for ovariole number and body size were both approximately 1.1 × 104. Thus, MSB can explain the level of variation, if mutations affecting these traits are under very weak selection, which is inconsistent with the empirical observation of stabilizing selection, or if the estimate of VM is biased downward by two orders of magnitude. GEI is a possible alternative explanation.

scholarly journals DEVELOPMENTAL STABILITY OF DROSOPHILA MELANOGASTER UNDER ARTIFICIAL AND NATURAL SELECTION IN CONSTANT AND FLUCTUATING ENVIRONMENTS

Genetics ◽  
1980 ◽  
Vol 95 (4) ◽  
pp. 1033-1042
Author(s):  
Brian P Bradley
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Selection ◽  
Developmental Stability ◽  
Stabilizing Selection ◽  
Phenotypic Variance ◽  
Environment Interaction ◽  
Total Phenotypic Variance ◽  
Environmental Variance ◽  
Genotype Environment Interaction ◽  
Fluctuating Environments

ABSTRACT Populations of Drosophila melanogaster in constant 25λ and fluctuating 20/29λ environments showed increases in developmental stability, indicated by decreases in bilateral asymmetry of sterno-pleural chaeta number. In both environments, rates of decrease in asymmetry were greater under natural selection (control lines) than under artificial stabilizing selection. Overall mean asymmetry was greater in the fluctuating environment.—There was no evidence that decreased asymmetry was due to heterozygosity, and the decline in asymmetry was not explained by the decline in chaeta number in the lines under only natural selection. However, the decline was consistent with changes in total phenotypic variance and environmental variance.— The divergence between lines after 39 generations of selection was seen in differences in asymmetry and also in the genotype-environment interaction expressed in cross-culturing experiments.

Genetic Variation and Causes of Genotype-Environment Interaction in the Body Size of Blue Tit (Parus caeruleus)

Genetics ◽  
1998 ◽  
Vol 148 (3) ◽  
pp. 1233-1244 ◽  
Author(s):  
Juha Merilä ◽  
James D Fry
Keyword(s):  
Genetic Variation ◽  
Body Size ◽  
Genetic Variance ◽  
Natural Populations ◽  
The Body ◽  
Environment Interaction ◽  
Parus Caeruleus ◽  
Genotype Environment Interaction ◽  
The Poor ◽  
Good Environment

Abstract In several studies of natural populations of birds, the heritability of body size estimated by parent-offspring regression has been lower when offspring have developed in poor feeding regimens than when they developed in good feeding regimens. This has led to the suggestion that adaptation under poor regimens may be constrained by lack of genetic variation. We examined the influence of environmental conditions on expression of genetic variation in body size of nestling blue tits (Parus caeruleus) by raising full sibs in artificially reduced and enlarged broods, corresponding to good and poor feeding regimens, respectively. Individuals grown in the poor regimen attained smaller body size than their sibs grown in the good regimen. However, there was among-family variation in response to the treatments—i.e., genotype-environment interactions (GEIs). Partitioning the GEI variance into contributions attributable to (1) differences in the among-family genetic variance between the treatments and (2) imperfect correlation of genotypic values across treatments identified the latter as the main cause of the GEI. Parent-offspring regressions were not significantly different when offspring were reared in the good environment (h2 = 0.75) vs. when they were reared in the poor environment (h2 = 0.63). Thus, there was little evidence that genetic variance in body size was lower under the poor conditions than under the good conditions. These results do not support the view that the genetic potential for adaptation to poor feeding conditions is less than that for adaptation to good conditions, but they do suggest that different genotypes may be favored under the different conditions.

Evaluation of genotype×environment interaction and stability of corn hybrids and relationship among univariate parametric methods

2014 ◽  
Vol 94 (7) ◽  
pp. 1255-1267 ◽  
Author(s):  
Mahdi Changizi ◽  
Rajab Choukan ◽  
Eslam Majidi Heravan ◽  
Mohammad Reza Bihamta ◽  
Farrokh Darvish
Keyword(s):  
Grain Yield ◽  
Regression Models ◽  
Coefficient Of Determination ◽  
Environment Interaction ◽  
Parametric Methods ◽  
Corn Hybrids ◽  
Environmental Variance ◽  
Genotype Environment Interaction ◽  
Desirability Index ◽  
Static Concept

Changizi, M., Choukan, R., Heravan, E. M., Bihamta, M. R. and Darvish, F. 2014. Evaluation of genotype×environment interaction and stability of corn hybrids and relationship among univariate parametric methods. Can. J. Plant Sci. 94: 1255–1267. There have been many approaches available in multi-location crop variety trial. However, the relationship among these approaches is not understood. In this study, therefore, grain yields of 16 corn hybrids were measured in 12 locations in Iran in 2011 and 2012 in order to compare the 23 parametric methods and to assess stability and adaptability of the hybrids. The combined ANOVA indicated that variances due to the genotypes, environments and genotype×environment interaction were substantially significant, which represents great variation among them. Principal component analysis based on rank correlation matrix indicated that stability methods can be classified into four groups. The group related to the dynamic concept and strongly associated with mean grain yield consisted of the measures, superiority index (Pi), desirability index (DI), geometric adaptability index (GAI) and genotypic stability (Di2 ). This group was more useful in agronomic goals in comparison with other methods. The second group also indicated the dynamic concept contained slope of regression models. The third group reflected the static concept included, the environmental variance (EV), the variance in regression deviation (S2di) and type IV stability concept ([Formula: see text]). The fourth group impressed concurrently by grain yield and stability included the measures coefficient of variability (CV), Wrick's ecovalence (W2), Shukla's stability variance (SH), Plaisted and Peterson's parameter (pp59), Plaisted's parameter (p60), yield reliability index (Ii), residual MS of regression models and coefficient of determination (R 2). Based on both concepts of stability (dynamic and static), hybrids (KLM76002/3×MO17), (KLM77002/10-5-1×K19/1) and (K47/2×MO17) were the most stable and (KSC704), (KSC720 (K74/1×K19)) and (K48/3×K18) were found to be the most adaptable to favorable environments. The methods of Pi, Di 2 , DI and GAI were more useful and more convenient than other methods. [Formula: see text] and [Formula: see text] showed an acceptable static concept of stability methods whereas study [Formula: see text] was more efficient than [Formula: see text].

scholarly journals Evaluation of stability in maize hybrids using univariate parametric methods

2021 ◽  
Author(s):  
Seyed Habib Shojaei ◽  
Khodadad Mostafavi ◽  
Amirparviz Lak ◽  
Ali Omrani ◽  
Saeed Omrani ◽  
...  
Keyword(s):  
Grain Yield ◽  
Climatic Conditions ◽  
High Yield ◽  
Environment Interaction ◽  
Average Yield ◽  
Stability Parameters ◽  
Environmental Variance ◽  
Maize Hybrids ◽  
Genotype Environment Interaction ◽  
The Stability

AbstractGenotype × environment interaction is one of the complex issues of breeding programs to produce high-yielding and compatible cultivars. Interaction of genotype × environment and make the more accurate selection, the performance and stability of hybrids need to be considered simultaneously. This study aimed to investigate stable genotypes with yield using 12 maize hybrids in different climatic conditions of Iran. The experimental design used was a randomized complete blocks design in three replications in two cropping years in Karaj, Birjand, Shiraz, and Arak stations. The simple analysis of variance performed on grain yield of genotypes indicated that all hybrids studied each year and station were significantly different in grain yield. Also, the combined analysis results showed a significant effect on the environment, the effects of genotype, and the interaction of genotype × environment and t in the studied hybrids different. Comparing Duncan's mean on the data obtained from the research, KSC705 genotypes with an average yield of 7.21 and KSC704 genotype with an average yield of 7.04 were identified as high yield cultivars. In order to identify stable cultivars, six stability parameters were used. KSC260 and KSC707 genotypes had stability Based on the environmental variance, also had stability based KSC705, KSC707 genotype on environmental the coefficient of variation, and KSC260 genotypes had stability based methods of genotype and environment interaction. As well as based on Eberhart and Russell regression coefficient had the stability to KSC400 and SC647 genotypes. Also, they were identified as the most stable genotypes based on the detection coefficient method, KSC707, and KSC703 genotypes.

The effect of different levels of management on the assessment of differences between varieties of chickens. 1. Eight-week body weight

1962 ◽  
Vol 4 (3) ◽  
pp. 319-327 ◽  
Author(s):  
J. C. Bowman ◽  
J. C. Powell
Keyword(s):  
Body Weight ◽  
Broiler Chickens ◽  
Environment Interaction ◽  
Environmental Variance ◽  
Components Of Variance ◽  
Management Level ◽  
Genotype Environment Interaction ◽  
Predetermined Level ◽  
Mean Differences ◽  
Different Levels

1. Analyses of records of eight-week body weight in broiler chickens have been carried out to estimate the effect of management level (measured by mean body weight of all varieties on each farm) on the components of variance due to differences between and within varieties, and to find out if there is any evidence of genotype-environment interaction.2. It was found that as management improved, the between-variety genetic variance remained constant or possibly increased whilst the withinvariety (genetic and environmental) variance decreased markedly. The cause of these regressions is not known.3. In four cases out of six there were significant genotype-environment interactions. In two cases, the genetic correlation between the performance of varieties on different locations was significantly different from 1·0.4. It is suggested that on the basis of these findings it would be necessary to select between varieties on records taken from chickens maintained under conditions similar to those in which they will eventually be used. However, fewer chickens would be required to measure, with a predetermined level of accuracy, mean differences on well managed farms than on poorly managed ones.

scholarly journals Ecological aspects of the heritability of body size in Drosophila buzzatii.

Genetics ◽  
1989 ◽  
Vol 123 (4) ◽  
pp. 803-813 ◽  
Author(s):  
T Prout ◽  
J S Barker
Keyword(s):  
Emerging Adults ◽  
Natural Environment ◽  
Selection Response ◽  
Stabilizing Selection ◽  
Environment Interaction ◽  
Thorax Length ◽  
Laboratory Environment ◽  
Drosophila Buzzatii ◽  
Genotype Environment Interaction ◽  
Ecological Aspects

Abstract The heritability of thorax length in the cactophilic Drosophila buzzatii was determined for flies from each of 10 rotting cactus cladodes. For each rot, emerging flies were used as parents of progeny reared in the laboratory. The methods used were full sib analysis with the parents mated assortatively and also offspring-parent regression. From this, heritabilities were measured for the laboratory environment and for the natural environment of the rotting cladode. For the laboratory environment, h2 = 0.3770 +/- 0.0203 and for the natural environment h2 = 0.0936 +/- 0.0087 within rots and h2 = 0.0595 +/- 0.0123 for a population drawn randomly from different rots. Because of the possibility of genotype-environment interaction between the laboratory and rot environments, the methods of B. Riska, T. Prout and M. Turelli were used to show it is possible that there is no such interaction, but if there is, the above natural heritabilities are approximate lower bounds. These results are related to the general problem of determining heritabilities in nature where it is impractical to measure both parents and progeny in nature. Determining heritability not only in nature but in relation to subdivision into ephemeral patches (cladodes in this case) has an important bearing on natural selection response and to general theories of stabilizing selection proposed to explain the existence of genetic variation. Attempts were made to detect selection by using the size of emerging adults as an indicator of various levels of larval stress. No selection was detected, but the power to do so was very weak. Differences between progeny means from different rots indicated some genetic differences between rots which can be adequately explained by small numbers of founders. This suggests a random fine scale subdivision amounting to FST = 0.1483 +/- 0.0462.

scholarly journals Pleiotropic stabilizing selection limits the number of polymorphic loci to at most the number of characters.

Genetics ◽  
1989 ◽  
Vol 122 (2) ◽  
pp. 459-463
Author(s):  
A Hastings ◽  
C L Hom
Keyword(s):  
Stabilizing Selection ◽  
Antagonistic Pleiotropy ◽  
Environment Interaction ◽  
Selection Scheme ◽  
Polymorphic Loci ◽  
Independent Components ◽  
Genotype Environment Interaction ◽  
Mean Fitness ◽  
The Mean ◽  
Rule Out

Abstract We demonstrate that, in a model incorporating weak Gaussian stabilizing selection on n additively determined characters, at most n loci are polymorphic at a stable equilibrium. The number of characters is defined to be the number of independent components in the Gaussian selection scheme. We also assume linkage equilibrium, and that either the number of loci is large enough that the phenotypic distribution in the population can be approximated as multivariate Gaussian or that selection is weak enough that the mean fitness of the population can be approximated using only the mean and the variance of the characters in the population. Our results appear to rule out antagonistic pleiotropy without epistasis as a major force in maintaining additive genetic variation in a uniform environment. However, they are consistent with the maintenance of variability by genotype-environment interaction if a trait in different environments corresponds to different characters and the number of different environments exceeds the number of polymorphic loci that affect the trait.

Additive-multiplicative approximation of genotype-environment interaction.

Genetics ◽  
1994 ◽  
Vol 138 (4) ◽  
pp. 1339-1349 ◽  
Author(s):  
A Gimelfarb
Keyword(s):  
Drosophila Melanogaster ◽  
Environmental Effects ◽  
Experimental Evaluation ◽  
Quantitative Traits ◽  
Directional Selection ◽  
Environment Interaction ◽  
Broad Sense Heritability ◽  
Degree Polynomial ◽  
Environmental Variance ◽  
Genotype Environment Interaction

Abstract A model of genotype-environment interaction in quantitative traits is considered. The model represents an expansion of the traditional additive (first degree polynomial) approximation of genotypic and environmental effects to a second degree polynomial incorporating a multiplicative term besides the additive terms. An experimental evaluation of the model is suggested and applied to a trait in Drosophila melanogaster. The environmental variance of a genotype in the model is shown to be a function of the genotypic value: it is a convex parabola. The broad sense heritability in a population depends not only on the genotypic and environmental variances, but also on the position of the genotypic mean in the population relative to the minimum of the parabola. It is demonstrated, using the model, that G x E interaction may cause a substantial non-linearity in offspring-parent regression and a reversed response to directional selection. It is also shown that directional selection may be accompanied by an increase in the heritability.

TO THE EXPERIMENTAL CONFIRMATION OF THE HYPOTHESIS ABOUT AN ECO-GENETIC NATURE OF THE PHENOMENON GENOTYPE * ENVIRONMENT INTERACTION FOR WOODY PLANTS

2018 ◽  
Vol 53 (1) ◽  
pp. 151-156 ◽  
Author(s):  
V.A. Dragavtsev ◽  
◽  
I.A. Dragavtseva ◽  
I.L. Efimova ◽  
A.P. Kuznetsova ◽  
...  
Keyword(s):  
Woody Plants ◽  
Experimental Confirmation ◽  
Environment Interaction ◽  
Genotype Environment Interaction ◽  
Genetic Nature
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