Molecular characterization and identification of three stored grain pests based on mitochondrial cytochrome C oxidase subunit I (COI) gene sequences

Abstract

Stored grain pests are discovered in food as immature stages, which further complicates the identification process. A DNA barcode dataset of some important pests that can be used for easy and confirm identification in stages of life is constructed. COI genes of three stored grain insect pests i.e,, Sitophilus oryzae, Callosobruchus chinensis and Oryzaephilus surinamensis were sequenced. The sequenced genes were submitted to NCBI GenBank and obtained accession numbers MG967331.1, MG967332.1, MG967333.1 and MK041216.1. BLAST analysis showed 99 to 100% homology with existing GenBank sequences. The nucleotide composition analysis revealed that the value of A+T (64.8%) is greater than G+C (35.2%). Genetic distance among four sequences of three store pests were ranged from 0.00293-0.32807. Phylogenetic analysis showed that these three species are originated from different clades. Haplotype analysis of mitochondrial COI gene of the stored grain insect pests showed high genetic diversity among them. C. chinensis, O. surinamensis and S. oryzae were separated from their common ancestor by 80, 73 and 64 mutational steps. These information may be helpful for attempting any successful control measures against the pest species. In conclusion, present author established the first DNA barcode dataset of three store grain pests and confirmed its efficiency for identifying these pests. Bangladesh J. Zool. 47(1): 1-11, 2019