Some nonlinear phenomena of nonlinear resonance, chaos, stochastic resonance and stochastic chaos occur in the laser-DNA interactive system, which make DNA mutated and broken up. The laser-radiated exogenous DNA was introduced into the tomato. It is beneficial to the expression of some characters of dominant genes of the donor and the improvement of the descendents qualities of receptors. The peroxidase isoenzyme of the donor, the receptor, and their descendents were analyzed. Our result shows that the pero................