[Objective] The research aimed to understand the genetic control of seed germination characters in dicotyledon plant using a suitable genetic model. [Method] An investigation of three seedling traits of seven parents and their F1s was undertaken in a diallel cross of sponge gourd （Luffa cylindrical Roem.） by germinating the seeds in two environments. A genetic model is developed to analyze the embryo effects as well as genotype × environment （GE） interaction effects of germination characters. [Result] Variations of the root length, shoot length and shoot dry weight were affected by genetic effects and environmental interaction effects. The three seedling traits were mainly controlled by genetic effect. Embryo dominance effects were the main genetic effect for root length and shoot length. Among the GE interaction effects, there only existed embryo dominance interaction effects for the three seedling traits. General narrow-sense heritabilities of shoot length and shoot dry weight were 7.0% and 27.3%, respectively. [Conclusion] The present modified genetic model could be used for investigating the genetic control of seed germination characters and seedling traits in dicotyledon plant.
