DNA fingerprint variability within and among the silkworm Bombyx mori varieties and estimation of their genetic relatedness using Bkm-derived probe

Genetic diversity within and among 13 silkworm varieties (6 diapausing and 7 nondiapausing) that differ in various quantitative and qualitative characters of economic importance was determined by DNA fingerprinting using Bkm-derived 2(8) probe. A high degree of genetic similarity was observed within each variety studied. Based on fingerprints of pooled DNA, the genetic similarity among various varieties was calculated. The dendrogram constructed using UPGMA resulted in the 13 varieties resolving into two major clusters. These two clusters were comprised of five nondiapausing as one group and five diapausing varieties as the other. The genetic similarity estimated within and among silkworms is consistent with the pedigrees and geographical distribution of the varieties. Our study has demonstrated that the variability of DNA fingerprints within and among silkworm can provide an essential basis on which breeders may plan crossbreeding strategies to produce potentially heterotic hybrids