Analysis of Quantitative Traits in PP9 Random Mating Sorghum Population 1

Crop Science ◽  
1981 ◽  
Vol 21 (5) ◽  
pp. 664-669 ◽  
Author(s):  
Tom S. Bittinger ◽  
R. P. Cantrell ◽  
J. D. Axtell ◽  
W. E. Nyquist
Keyword(s):  
Quantitative Traits ◽  
Random Mating

scholarly journals EFFECT OF SELECTION ON HERITABILITY AND GENETIC CORRELATION OF TWO QUANTITATIVE TRAITS IN MICE

1974 ◽  
Vol 16 (3) ◽  
pp. 599-609 ◽  
Author(s):  
T. K. Cheung ◽  
R. J. Parker
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Quantitative Traits ◽  
Random Mating ◽  
Tail Length ◽  
Control Group ◽  
Mass Selection ◽  
Initial Population ◽  
Significant Difference ◽  
Selection For

The effects of different intensities of single trait directional selection on the heritability and genetic correlation of two quantitative traits in random mating populations of mice were observed during 14 generations. The initial population was divided at random into five groups (A, B, C, D and E). Group A and Group B were under 30% and 60% mass selection for large 6-week body weight, respectively. Group C and Group D were under 30% and 60% mass selection for long 6-week tail length, respectively. Group E acted as control group with no selection applied. In all groups, the parent population consisted of 15 males and 30 females each generation, mated at random.Direct selection had no apparent effect on the heritability of either the trait under selection or the correlated trait over the 14 generations. Heritability of 6-wk tail length was higher than the heritability of 6-wk body weight. Estimates of heritability of 6-wk tail length ranged from 0.15 ± 0.22 to 0.68 ± 0.24, while estimates of heritability of 6-wk body weight ranged from 0.05 ± 0.17 to 0.33 ± 0.09. There was no significant difference among the estimates of genetic correlation between the two traits in the five selection groups. Estimates of realized genetic correlation between 6-wk body weight and 6-wk tail length seemed to indicate that more intense selection led to some decrease in genetic correlation between the two traits.

scholarly journals The contribution of quantitative trait loci and neutral marker loci to the genetic variances and covariances among quantitative traits in random mating populations.

Genetics ◽  
1995 ◽  
Vol 139 (1) ◽  
pp. 445-455 ◽  
Author(s):  
A Ruiz ◽  
A Barbadilla
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Quantitative Traits ◽  
Random Mating ◽  
Unbiased Estimation ◽  
Limited Information ◽  
Trait Loci ◽  
Marker Loci ◽  
Neutral Marker ◽  
Variance Explained

Abstract Using Cockerham's approach of orthogonal scales, we develop genetic models for the effect of an arbitrary number of multiallelic quantitative trait loci (QTLs) or neutral marker loci (NMLs) upon any number of quantitative traits. These models allow the unbiased estimation of the contributions of a set of marker loci to the additive and dominance variances and covariances among traits in a random mating population. The method has been applied to an analysis of allozyme and quantitative data from the European oyster. The contribution of a set marker loci may either be real, when the markers are actually QTLs, or apparent, when they are NMLs that are in linkage disequilibrium with hidden QTLs. Our results show that the additive and dominance variances contributed by a set of NMLs are always minimum estimates of the corresponding variances contributed by the associated QTLs. In contrast, the apparent contribution of the NMLs to the additive and dominance covariances between two traits may be larger than, equal to or lower than the actual contributions of the QTLs. We also derive an expression for the expected variance explained by the correlation between a quantitative trait and multilocus heterozygosity. This correlation explains only a part of the genetic variance contributed by the markers, i.e., in general, a combination of additive and dominance variances and, thus, provides only very limited information relative to the method supplied here.

Simultaneous estimation of additive and dominance genetic variance in heterozygous and homozygous populations

1985 ◽  
Vol 27 (1) ◽  
pp. 114-120 ◽  
Author(s):  
J. D. Patel ◽  
K. S. Bains ◽  
G. S. Chahal
Keyword(s):  
Quantitative Traits ◽  
Genetic Variance ◽  
Random Mating ◽  
Simultaneous Estimation ◽  
Random Mating Population ◽  
Genetic Variances ◽  
Final Experiment ◽  
Mating Population ◽  
Dominance Genetic Variance ◽  
Inbred Populations

A new mating procedure for estimating additive and dominance genetic variances in a random mating population is presented. With this procedure, m number of plants from a random mating population are selfed to produce S1 families and are also crossed to n inbreds. Subsequently, all the m × n hybrids are selfed. while keeping remnant crossed seeds for the final experiment. The final experiment comprises m × n hybrids, their m × n selfs, m S1, and m S2 families as well as n inbreds. The analysis of the data, recorded on the quantitative traits provides information for both the random mating as well as the inbred populations. Epistasis can be detected by two different tests. The analysis can be applied to F2 instead of random mating populations with less effort.Key words: random mating, genetic variance, epistasis, inbred.

Effect of F2 Inter se Mating on Quantitative Traits Mean, Range, Variance and Heritability in Dolichos Bean (Lablab purpureus L. Sweet var. Lignosus)

2021 ◽  
Author(s):  
Chandrakant . ◽  
S. Ramesh ◽  
P.V. Vaijayanthi ◽  
A. Mohan Rao ◽  
M.S. Shivakumar
Keyword(s):  
Quantitative Traits ◽  
Additive Genetic Variance ◽  
Random Mating ◽  
Lablab Purpureus ◽  
Narrow Sense Heritability ◽  
Flowering Synchrony ◽  
F2 Population ◽  
F2 Generation ◽  
Pure Lines ◽  
The Impact

Background: Pedigree method of breeding in predominantly self-pollinated crop like dolichos bean enable exploiting only fixable genetic effects as a result of rapid increase in homozygosis. One or a few cycles of inter-mating in F2 generation help create populations with high frequency of desired recombinants which otherwise cannot be realized in later generations. The objective of the present investigation was to assess the impact of inter se mating in F2 population on nine quantitative traits’ (QTs) mean and variability parameters.Methods: Randomly selected 20 pairs of a single cross-derived F2 plants with flowering synchrony were inter se mated. Progenies derived from 20 paired crosses (designated as BIP F3 progenies) and those (F3) derived from their 40 F2 parents were evaluated for 9 QTs. Statistics such as mean, absolute range (AR) and standardized range (SR), variance (σ2), additive genetic variance (σ2A) and narrow-sense heritability (NS-h2) were estimated. BIP F3 progenies were compared with those of F3 progenies for QTs mean, AR/SR, σ2, σ2A and NS-h2. Significance of differences between BIP F3 progenies and F3 progenies for mean and σ2 were examined using two-sample t test and Levene’s tests, respectively. Result: The random mating in F2 population was effective in increasing the means, variances, σ2A and NS-h2 of racemes plant-1, fresh pods node-1, fresh pods plant-1 and fresh pod yield plant-1 in dolichos bean. Considering that random mating followed by selfing is a method of genetic improvement for future breeding rather than for immediate use, our results suggest long-term genetic gain and better prospects of deriving superior pure-lines with desired traits/combination of traits from inter-mated population in dolichos bean.

Numerical Analysis of the Age-Sex-Structured Population Dynamics Taking into Account Spatial Diffusion

2005 ◽  
Vol 10 (4) ◽  
pp. 365-381 ◽  
Author(s):  
Š. Repšys ◽  
V. Skakauskas
Keyword(s):  
Population Dynamics ◽  
Numerical Analysis ◽  
Population Model ◽  
Local Stability ◽  
Deterministic Model ◽  
Random Mating ◽  
Spatial Diffusion ◽  
Neumann Problems ◽  
Structured Population ◽  
Structured Population Dynamics

We present results of the numerical investigation of the homogenous Dirichlet and Neumann problems to an age-sex-structured population dynamics deterministic model taking into account random mating, female’s pregnancy, and spatial diffusion. We prove the existence of separable solutions to the non-dispersing population model and, by using the numerical experiment, corroborate their local stability.

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