Abstract: The genomic DNA in the fresh leaves of Caragana microphylla was extracted using a modified SDS method, and then an AFLP silver-stained analysis system suitable for C.microphylla was established by optimizing several main factors. We found that the genomic DNA obtained had good purity and integrity for AFLP analysis with mercapto-ethanol in the extracting solution to prevent formation of oxides and PVP to eliminate phenol from genomic DNA. 500 ng genomic DNA was digested for 4 h with EcoRⅠand MseⅠrestriction enzymes, ligated to adaptors for 12 h at 16℃, pre-amplified using EcoRⅠ+1 and MseⅠ+1 primers and then amplified using EcoRⅠ+3 and MseⅠ+3 primers. The amplified products were resolved in denaturing ployacrylamide gels and stained with silver. With this system, clear ploymerphic fingerprints were obtained, which can be taken as a base for future study of AFLP for C.microphylla populations.

Key words: Caragana microphylla, DNA extraction, AFLP, silver-stained