(1992, 1993) that "models assuming strictly additive genetic effects
, even if appropriate at the within-population level, may tell us little about the actual genetic divergence of populations." We might add that assuming other nonlinear effects such as genotype-by-environment interaction can be ignored may also be misleading.
Additive genetic effects
<a, [??], heat tolerance (fv, [??]), and additive genetic effects
plus heat tolerance (a+fv,[??]).
Most of crosses with good SCA effects may be either due to good GCA of parents, indicating the preponderance of additive genetic effects
(Kenga et al., 2004).
Genotypic variance observed in the [F.sub.2] generation in this study might be attributed primarily to additive genetic effects
, since the variance estimates of this effect were substantially greater than the variance estimates of dominance (Table 2).
Multiple Trait Gibbs Sampler for Animal Models (MTGSAM) was employed (Van Tassell & Van Vleck, 1995), which executes Bayesian estimates; normal a priori distribution may be taken into account for additive genetic effects
, common environment of larva culture, nursery and residual.
The average of nearly 100 estimates indicate that, assuming no epistasis and no linkage, additive genetic effects
on average account for 61.2% and dominance accounted for 38.8% of total genetic effects (cf., Hallauer and Miranda, Fo., 1988).
Following the model developed by Kirkpatrick and Lande (1989) for maternal inheritance, the offspring trait can be decomposed into three parts: (1) additive genetic effects
([a.sub.o]); (2) random environmental effects ([e.sub.o]); and (3) maternal environmental effects, such that
The association between genotypes and marbling was significant (P<0.0001), showing that genotypes AA (5.866 +- 0.15) had a more significant effect on MAR followed by GG (5.325 +- 0.08) and AG (5.034 +- 0.09), with significant additive genetic effects
Where, Y is a vector corresponds to the phenotypic values for weight gain traits and growth curve parameter traits; b is the vector of fixed effects including batch, lines, sex, and; a is a vector of random additive genetic effects
, assumed to be a ~ N (0, A [[sigma].sup.2.sub.a])
In the threshold model, it was assumed that the underlying (Liability) scalehas a normal continuous distribution, being represented as: |[theta] ~ N(W[theta], I[[sigma].sub.e.sup.2]), where is U the base scale vector of order r; [theta]=(b.a) is the location parameter vector of order s with b (defined as fixed effects from the frequency point of view), and order s with a (as random direct additive genetic effects
); W is the known incidence matrix of order r x s; I is the identity matrix of order r x r and [[sigma].sub.e.sup.2] is the residual variance.
[gamma] = vector of the observations for the trait (W205); X = matrix of incidence of the fixed effects (CG, sex, BS, WS e CA); [Z.sub.1] = matrix of incidence associated with direct additive genetic effects
; [Z.sub.2] = matrix of incidence associated with maternal additive genetic effects
; [beta], a and [epsilon] = vector of solutions for the fixed effects, vector of direct additive genetic effects
and vector of maternal additive genetic effects
, respectively and e = vector of residues.
The percent phenotypic variation explained by the significant intervals and estimates of their additive genetic effects
were also calculated in MapQTL.