Abstract: The DNAs of immaturate, maturate tomatoes and sweet peppers were extracted by SDS method. The detection resultsof inner rbcL gene were positive, showing that the DNAs were extracted successfully and there were no substance restrainingpolymerase chain reaction(PCR) in the DNAs. The detection results of Cauliflower mosaic virus(CaMV) 35S promoter,Agrobacterium tumefaciens nopaline synthase(nos) terminator and Escherichia coli strain K12 neomycin phosphotransferaseⅡ(nptⅡ) gene in the tomatoes and sweet peppers with triplex PCR were negative. The multiplex PCR detecting simultaneity innerrbcL gene, nptⅡ gene, CaMV 35S promoter and nos terminator were experimented successfully, with the mixture templet of theDNAs of tomato, sweet pepper and positive plasmid pBI121. The multiplex PCR was quick, simple and practical, and mightplay an important role on the detection of genetically modified food.

Key words: tomato, sweet pepper, genetically modified component, multiplex polymerase chain reaction