Dominance theory and overdominance theory are the basic theories of heterosis mechanism. It is difficult to explain some
sophisticated heterosis phenomena according to these two theories. The concepts of isogene and isoprotein were developed according to the gene primary structure characteristics. Based on the basic model of heterosis process study, the
resultant genetic vibration theory of heterosis mechanism was proposed according to the resultant action of the same genes in diploid crops. This theory is as followed: 1) The law of isoprotein synthesis encoded by isogenes is a kind of
Vibration, which is defined as genetic vibration. The resultant vibration of two or more isoproteins is defined as resultant genetic vibration. 2) The resultant genetic vibration in F 1 shows positive, none, or negative heterosis as the time goes on, which affects the metabolicreaction so that the products of the metabolic reaction appears positive, none, or negative heterosis as the time goes on. 3) The similar action of other kinds of isogenes, the interaction of different metabolic reaction and the effects of environmental factors on isogenes in plants ultimately affect the phenotypic traits and make the trait heterosis possess the process characteristics. This theory is a dynastic one, and dominance theory and overdominance theory are only the special cases of resultant genetic vibration theory.