Abstract: n a population of Glycine soja L., the polymorphic loci could be hardly detected by RAPD markers, using several primers. These non-polymorphic amplification products were cleaved by some restriction endonuclease, such as Msp Ⅰ , Hinf Ⅰ , Taq Ⅰ , EcoR Ⅰ , Sal Ⅰ , Dra Ⅰ and Hae Ⅲ. After cleaving, the digested amplification products were detected on polyacrylamide gel electrophoresis with silver staining. It was found that: 1 ) some restriction endonucleases could not, and some others could effectively digest the random amplication products of the DNAs of G. soja; 2) some endonucleases could produce polymorphic DNA fragments after digestion of the non-poly-morphic products, but others could not even after digestion; 3) non-polymorphic amplification products amplified by some primers could produce polymorphic DNA fragments after digestion, while those by other primers could not. It could be concluded that the restriction endonuclease digestion of amplification products could increase significantly detectability of polymorphic DNA by RAPDs technique.

Key words: Random amplified polymorphic DNA, Restriction endonuclease, Polymorphic DNA fragment, Population of Glycine soja