Abstract: The genetic diversity of fifty-nine silkworm strains and mulberry wild silkworm, Bombyx mandarina (M.), was investigated at DNA level using the random amplified polymorphic DNA (RAPD) method. Silkworm strains were classified into six groups according to the voltinism, moltinism and the geographic areas initially obtained. Of 34 arbitrary 10-base primers that were tested, 12 (35.29%) were informative and yielded 103 bands, 86 (83.5%) of which were polymorphic bands with a mean of 7.2 bands per primer. RAPD data were used to generate simple matching coefficients of similarity (SM). The SM were then used to construct a dendrogram by unweighted pair-group method with arithmetical averages (UPGMA). The study indicated thatRAPD were race-specific and geographic group-specific markers in silkworm; Chinese univoltine tetramoltine varieties seems to be differentiated form Bombyx mandarina M.In the earliest year; Chinese univoltine varieties should be placed into two distinct groups, I. E. , trimoltine varieties and tetramohine varieties.

Key words: Bombyx mori (L.), Bombyx mandarina (M.), genetic diversity, RAPD, molecular dendrogram