Abstract: According to the requirement of PCR, with the improved CTAB method, taking tomato as material, the minipreparation DNA of tomato leaf was realized; Although the organization quantity which used to extract the genome DNA is few, and the genome DNA has degenerated after the electrophoresis, but was sufficient for uses in the PCR examination. taking it as the template to amplify the DNAmβ and 1.7A of the Su gene silencing plant induced by Tomato yellow leaf curl China virus, the fragment size was 1 300 bp and 500 bp,respectively. The result of sequence determined is the corresponding gene partial fragments. This method does not need to use liquid nitrogen, can operate independently, and can stablely and accurately formalizated the PCR examination in the gene silence tomato plant.

Key words: PCR, method of mini-preparation DNA, tomato