Genetic characterization of Spermophagus niger (Coleoptera: Chrysomelidae: Bruchinae: Amblycerini) pest associated to seeds of Sorrel (Hibiscus sabdariffa L.) in Burkina Faso

Abstract

In Burkina Faso, the seeds of sorrel, Hibiscus sabdariffa L. are attacked by a pest identified morphologically as Spermophagus niger which is maintained all year on seeds and causing considerable damages. In the current study, for the first time, genetic characterization for S. niger was performed to determine its genetic identity and place it in its phyletic group. Mitochondrial gene, the Cytochrome oxidase I (COI) of the pest was partially sequenced after extraction and amplification by Polymerase Chain Reaction (PCR). Then the variability of genetic parameters namely the number of polymorphic and monomorphic sites, the frequencies of the different nucleotides and amino acid composition were determined. The nucleotide sequence of S. niger ob-tained was submitted in Genbank and the accession number is KU710716. Nucleotide sequences of S. niger obtained and those of different species of Spermophagus and Z. subfasciatus available in the GenBank database, we determined the percentage of similarity on the one hand and kinship through Phylogenetics reconstructions on the other hand. The results showed the absence of polymorphic sites for 406 sites obtained with 36.5% of thymine, 17.5% of cytosine, adenine 31% and 15% of guanine. Leucine was the majority amino acid (14.50%); the lysine was minority amino acid (0.76%) and cysteine was absent. The percentage of similarity obtained and phylogenetics reconstructions showed that S. niger is very close to the different species of Spermophagus particularly S. drak and different from Z. sub-fasciatus.