a, additive effect; aa, epistasis effect; ae1, additive by environment interaction effect in 12 h day length in the spring sowing (SD + LT); ae2, additive by environment interaction effect in natural day treatment in the spring sowing (SP); ae3, additive by environment interaction effect in 16 h day length in the spring sowing (LD + LT); ae4, additive by environment interaction effect in 12 h day length in the summer sowing (SD + HT); aae2, epistasis by environment interaction effect in natural day treatment in the spring sowing (SP); -Log10P = minus log10(P-value); h2(%) = heritability(%)