Analysis of genetic diversity and phylogeny of Philosamia ricini (Lepidoptera: Saturniidae) by using RAPD and internal transcribed spacer DNA1

The Indian Eri silkworm, Philosamia ricini Hutt, a commercial silk producing insect, is believed to have originated in the Brahmaputra valley of Assam. In this study, the genetic diversity and phylogenetic relationships of six morphs of Eri silkworm viz. white plain, white zebra, white spotted, blue plain, blue zebra and blue spotted collected from different geographical locations of North-East India were investigated by using random amplified polymorphic DNA (RAPD) and the first internal transcribed spacer region (ITS1). This study revealed a low genetic diversity among the morphs of Eri silkworm. Twenty-eight random primers generated 199 bands. Out of these, 112 were polymorphic (56.28%) with an average of 7.1 bands per primer. The genetic similarity matrix ranged from 0.56 to 0.99. The morphs collected from same geographical area shared the same cluster in the dendrogram. The genetic diversity in case of ITS1 sequences (2.19%) was found to be less as compared to RAPD. The ITS1 sequences of the morphs collected from same geographical area were found to be identical. The information generated in this study will help in conservation and effective breeding program to improve its productivity.