3. The characteristics of heterotic Performance in plants (1)Multiple-character Phenomenon (2) Related to Parental Genetic Difference 3 ) Related to Parental homozygosity (4) Environment Dependent (5) Depression of Heterosis in F2 and later generations 4. The fixation of heterosis P.1203. The Characteristics of Heterotic Performance in Plants (1) Multiple-character Phenomenon (2) Related to Parental Genetic Difference (3) Related to Parental Homozygosity (4) Environment Dependent (5) Depression of Heterosis in F2 and later generations 4. The Fixation of Heterosis P.120