Molecular Identification using Next Generation Sequencing (NGS) Technology for the grain sawfly, Oryzaephilus surinamensis Prevalent on Various Grain Species in Karbala Governorate, Iraq

Abstract

This study included molecular characterization of the saw-toothed grain beetle, Oryzaephilus surinamensis L., which is an important insect pest that infests stored products, especially stored grains and dates in Iraq, causing significant economic losses. To provide novel molecular insights into this pest, genomic and symbiotic bacteria analyses were conducted. Results obtained showed that the nucleotides sequence of the double-stranded DNA of the beetle O. surinamensis spread in Karbala Governorate using NGS technology, through the identification of the mitochondrial cytochrome oxidase subunit I (mtCOX1) gene sequence. The molecular identification of the two genetic markers cytochrome c oxidase subunit I and the Large ribosomal subunit genes proved that the insect is the saw-toothed grain beetle O. surinamensis because of high similarity rates of 99% and 92%, respectively, when compared with global references of the same insect. The genetic analysis showed the presence of genetic kinship of the studied isolate with many global isolates that belong to the same species through their grouping in the same branch. Accession numbers PV839593 and PV809953 to these genes of O. surinamensis Karbala-1 isolate in the GenBank were assigned. The results also showed the presence of a symbiotic bacteria with the saw-toothed grain beetle, identified as Flavobacteriales sp. for the first time in Iraq. These bacteria showed 98.1% sequence homology and 100% coverage rate when compared with the reference 16S rRNA gene of the same bacteria. This bacterial sequence was deposited in the GenBank under the accession number PV809954. In addition, another bacterial endosymbiont of O. surinamensis Karbala-1 isolate was molecularly identified as Wolbachia sp., as it showed 97.5% sequence homology and 95% coverage rate when compared with known sequences of reference bacteria. The gene sequence of these bacteria was also deposited in the GenBank.

Keywords:

Sawfly beetle Oryzaephilus surinamensis, NGS, Flavobacteriales sp.