Abstract:Electrophoretic isozyme zymogram patterns of peroxidase (POD), cytochrome oxidase (COD), esterase (Est), α-amylase (α-Amy), catalase (Cat), Glutamate dehydrogenase (GDH), Malate dehydrogenase (MDH), superoxide dismutase (SOD), acid phosphatase (Acp), etc. obtained from 108 maize inbred lines and their 199 hybrids were analyzed. The soluble protein patterns from these materials were tested as well. The authors had probed into the relationship between the index of zymogram difference and potential yield of heterosis in maize. The results indicated that hybrids from parents which showed high zymogram difference index could produce high heterosis and those from parents which had low zymogram difference index could also produce high heterosis as well. But hybrids from the sister lines which had lower zymogram difference index could only produce lower heterosis. There was no significant statistical difference between isozyme zymogram difference index and potential yield of heteroSis on a genetic background with complex combinaton.