Fingerprint analysis of Bombyx mori local variety resources based on SSR markers

Abstract

41 Simple Sequence Repeats (SSR) markers were used to research the fingerprints of 96 silkworm local variety resources, including 83 Chinese univoltine varieties, 11 Chinese bivoltine varieties and 2 Japanese bivoltine varieties. These SSR markers showed rich polymorphism, with the number of alleles reaching 3-35, averaged 12.78, suggesting that there was rich SSR polymorphism among various local varieties and its polymorphism information content ranged from 0.162-0.958, averaged 0.690. The genetic distance between the various varieties was calculated from their fingerprints. By using UPGMA method, unique patterns of clustering among local species of silkworm were revealed. These included the patterns of 5 groups comprising of 54 varieties, while the other 42 species clustered in twos or threes, and as single nodes. In addition, the clustering among varieties did not indicate any obvious groups based on voltinism or moltinism, which seemed to support the theory of multiple origin of silkworm. The results prove that SSR markers can provide a fingerprint analysis of silkworm varietal resources and can be used for their classification and identification.