Estimation of gene action in F2 population

complementary gene Thakur and Hillerislambers 1988, as well as over-dominant effect of elongation and a positive transgression for plant height Mishra et al. 1996. Genetic model with six parameter analysis on number of productive tiller resulted in four appropriate model, that were m [d] [h] [i] [j], m [d] [h] [i] [l], dan m [d] [h] [j] [l]. Components of genetic which were significantly different were additive gene [d] and its interaction [i], dominant gene [h] and its interaction [l], and also additive x dominant [j] Table 4.3 and 4.4. Appropriate genetic models for flowering date were m [d] [h] [i], m [d] [h] [l], m [d] [h] [i] [j], m [d] [h] [i] [l], dan m [d] [h] [j] [l]. Effect of component of genetic model which were significantly different were additive gene [d], dominant [h], additive x additive interaction [i], and dominant x dominant interaction [l]. Meanwhile appropriate genetic model for panicle length were m [d] [h] [l], m [d] [h] [i] [j], m [d] [h] [i] [l], and m [d] [h] [j] [l]. T test was used on the model with complete component, that were on m [d] [h] [i] [j], m [d] [h] [i] [l], dan m [d] [h] [j] [l]. Based on t test, dominant gene action [h], additive x additive interaction [i], additive x dominant interaction [j], and dominant x dominant interaction [l] had significant effect on these models. Based on the goodness of fit, appropriate genetic model for weight of 100 grain were m [d] [h] [i], m [d] [h] [l], m [d] [h] [i] [j], m [d] [h] [i] [l], and m [d] [h] [j] [l]. Component of genetic with significant effect were additive gene, dominant gene, additive x additive interaction, additive x dominant interaction, and dominant x dominant interaction. Table 4.3 Goodness of fit testing χ 2 genetic model with six parameter from IR 42 x IRRI 119 rice crossing under stagnant flooding stress Trait m [d] [h] [i] m [d] [h] [j] m [d] [h] [l ] m [d] [h] [i] [j] m [d] [h] [i] [l] m [d] [h] [j] [l] Plant height 2.805 ns 16.72 0.589 ns 0.542 ns 0.542 ns 0.542 ns No. of tiller 8.094 62.582 31.061 3.219 ns 3.219 ns 3.219 ns Flowering time 0.904 ns 10.004 1.859 ns 0.855 ns 0.855 ns 0.855 ns Panicle length 9.485 28.683 3.993 ns 0.351 ns 0.351 ns 0.351 ns 100-grain weight 6.468 0.898 ns 4.972 ns 0.823 ns 0.823 ns 0.823 ns Grain yield 0.779 ns 18.317 5.627 ns 0.312 ns 0.312 ns 0.312 ns Additive gene has opposite direction to dominant gene [h] indicating that the allele responding in decreasing the phenotypic of the trait as shown by number of tiller, panicle length, and grain yield. Opposite direction between dominant [h] and dominant x dominant interaction [l] indicating that the trait is controlled by duplicate epistasis. Existence of epistasis and higher magnitude of dominant [h] and interaction dominant x dominant [l] will reduce efficiency of selection. Type of epistasis depends on the crossing, environment, and occasionally generating interaction between both of them Cao et al. 2002.