This indicated that additive gene action
was prominent and showed simple inheritance for the improvement of spikelets spike-1.
However, the contribution of the additive gene action
was higher than that of nonadditive gene action for all the traits.
Genetic effects observed in our study, specifically those involved in the inheritance of the resistance to nematodes, may be explained to a large extent by the additive-dominant model, represented by the sum of the effects of the mean (m), additive gene action
(a), and dominance (d), since the correlation between the averages estimated by the model and the averages obtained from the generations was high (R2 = 0.9745).
A narrow-sense heritability estimates of 26.0% and 50.0% indicated a below average proportion of variability due to additive gene action
in plant height and an average proportion of variability in the inheritance of plant height could be due to non-additive gene action.
Dominance and additive gene actions
are effectively used for the improvement of hybrids (Kumar et al., 2012).
Its values did not significantly exceed those expected from additive gene action
(2F[V.sub.A0], Wright 1952).
Ginning out-turn was influenced by additive gene action
(Ali et al., 2008; Khan et al., 2009).
Yet, pre-dominance of non-additive gene action was observed for ginning outturn and 2.5% span length, while preponderance of additive gene action
was obtained in seed cotton yield, boll weight and fibre elongation.
This QTL reduced damage ratings by 0.25 to 0.3 points for both insects and expressed additive gene action
. Fifteen percent of the genetic variation in the model was explained by LDR11 for southwestern corn borer resistance and 36% for fall armyworm resistance.
Variance due to general combining ability (GCA) is indicator for extent of additive gene action
whereas; variance due to specific combing ability (SCA) shows the extent of non-additive gene action.
High heritability along with high genetic gain was observed for fruit borer infestation indicating additive gene action
for this trait.
Genetic mapping using SSR markers in the [F.sub.2] and [F.sub.4:5] populations was additional evidence that both major and minor genes with additive gene action
controlled resistance in soybean to Rhizoctonia root and hypocotyl rot, and that moderately susceptible cultivars also contributed resistant alleles.
Additive gene action
was more important than non-additive gene action for grain yield.
napus) have indicated that additive gene action
is the main genetic factor in the control of seed oil content with dominance and epistasis being not significant (Grami and Stefansson, 1977: Engqvist and Becker, 1991).