# Table 1 Simulated epistatic model for two-locus interactions

Genotype locus B

Genotype locus C

CC

Cc

cc

BB

$$e_{00} = \mu + a_{B} + a_{C} + k$$

$$e_{01} = \mu + a_{B} + d_{C} + m$$

$$e_{02} = \mu + a_{B} - a_{C} - k$$

Bb

$$e_{10} = \mu + d_{B} + a_{C} + l$$

$$e_{11} = \mu + d_{B} + d_{C} + n$$

$$e_{12} = \mu + d_{B} - a_{C} - l$$

bb

$$e_{20} = \mu - a_{B} + a_{C} - k$$

$$e_{21} = \mu - a_{B} + d_{C} - m$$

$$e_{22} = \mu - a_{B} - a_{C} + k$$

1. First, nine epistatic effects ($$e_{00}$$ to $$e_{22}$$) were simulated randomly, by sampling for each effect an epistatic degree ($$\varepsilon$$) from a normal distribution and scaling them by the additive effects of the two loci (i.e. $$e_{00} = \varepsilon_{00} \sqrt {\left| {a_{B} a_{C} } \right|}$$). Then, those nine epistatic effects were used to estimate the separate functional additive ($$a_{B}$$ and $$a_{C}$$), dominance ($$d_{B}$$ and $$d_{C}$$), additive-by-additive ($$k$$), additive-by-dominance ($$l$$ and $$m$$) and dominance-by-dominance ($$n$$) epistatic effects that were underlying those epistatic effects 