The inheritance of elongating ability under submergence in floating rice was studied using a cross Tan-ginbozu×Aswina: Tan-ginbozu is a mutant deficient in gibberellins and Aswina is a common floating variety of rice from Bangladesh. Internodal elongation of F₁ plants under submergence showed incomplete dominance. Ability of internodal elongation can be explained in terms of complementary genes, one controls gibberellin production and the other controls responsiveness to ethylene.