Abstract: 【Aim】 This study aims to investigate the effects of feed on intestinal microflora of different silkworm (Bombyx mori) varieties. 【Methods】 The polyphagous silkworm strain GS and common silkworm strain 1015 were fed with mulberry leaves (groups GS.m and C1015.m) and artificial diet (group GS.b), respectively, and the intestinal samples of the 4th instar larvae of B. mori were collected. The V3-V4 region of the 16S rDNA of intestinal microorganisms was sequenced by using the high-throughput sequencing method, and the differences in intestinal microflora between the two strains were compared.【Results】 The results showed that the dominant bacteria in B. mori intestine at the phyla level were Firmicutes and Proteobacteria, those at the family level were Leuconostocaceae, Lactobacillaceae and Enterobacteriaceae, and those at the genus level were Weissella, Lactobacillus, Buchnera, Methylobacterium, Phyllobacterium, Enterococcus, Bacteroides, etc. After GS was fed with mulberry leaves and the artificial diet, Methylobacterium and Buchnera were present only in the intestine of GS fed with mulberry leaves, while Weissella and Brevibacillus appeared only in the intestine of GS fed with the artificial diet. The common dominant intestinal bacteria in silkworm strains GS and 1015 fed with mulberry leaves were Phyllobacterium, Bacteroides, Acinetobacter, etc. Compared with the intestinal microflora of the GS strain, Enterococcus, Herbaspirillum and Thiothrix were detected only in the strain 1015. The species diversity of intestinal bacteria in group GS.b was lower than those of groups GS.m and C1015.m. The intestinal bacteria whose abundance showed the most significant difference was Proteobacteria in GS.m,  Bacilli  and Lactobacillales in GS.b, and Enterococcus and Enterococcacea in C1015.m. 【Conclusion】 The intestinal microflora in different silkworm strains (GS and 1015) fed with mulberry leaves are more consistent as compared to that in silkworm strains fed with the artificial diet. The species diversity of intestinal microflora in the polyphagous silkworm fed with mulberry leaves is higher than that in the polyphagous silkworm fed with the artificial diet.

Key words: Bombyx mori, high-throughput sequencing, 16S rDNA, intestinal microflora, species diversity