Abstract: AFLP markers were mapped using BC₁ population ［od₁₀₀×(782×od₁₀₀)］. From 47 BC₁ samples 430 polymorphic markers were detected using an improved method of AFLP, called silver staining AFLP, which was to some extent different from the original AFLP method, called radiation AFLP. In this study 17 AFLP primer pairs and two restriction enzymes PstⅠ and TaqⅠ were used. Being tested by chi-square test under　P=0.05 level for 1∶1 segregation proportion, 253 valid loci that might be used in mapping were obtained. The ratio of the valid loci to polymorphic loci was 58.84%. Twenty eight linkage groups with 163 loci were mapped by using Mapmaker/Exp(Version 3.0b), in which we set LOD=3.0 and maximum recombination fraction= 0.3, and Kosambi function. There were 90 unlinked loci in these 253 valid loci and the ratio of mapping loci to valid loci was 64.43%. The number of loci mapped in the 28 groups was at a range of 2～28 and there were 5.8 (average value) loci per group. The total length of the groups was 2 998.9 cM. The lengths of the 28 groups varied at a range of 4.5～652.8 cM and the average distances between loci on the 28 groups were at a range of 4.5～36.7 cM. The average length of groups was 107.1 cM.

Key words: silkworm, molecular marker, AFLP, linkage map