Genetic study of two populations of Sitophilus oryzae following two types of maize: Yellow maize and yellow-white maize from two different localities in Senegal

Abstract

The objective of this study is to determine the genetic diversity and structure, demographic evolution and phylogenetic relationships of Sitophilus oryzae (S. oryzae) in two types of maize: yellow maize and yellow-white maize from two localities in Senegal. Thus, individuals of S. oryzae from each locality are used, after sampling and massive rearing. The Cyt-B gene of the mitochondrial DNA (deoxyribonucleic acid) was targeted and sequenced. The obtained sequences are corrected, aligned and exploited. Overall, haplotypic diversity (Hd) is non-significantly high (0.895 ±0.058) while nucleotide diversity (Nd) is significantly low (0.016±0.003), even when populations are considered separately; the Salemata population (Hd=0.949 ±0.051, Nd= 0.015±0.003) is more diverse with P-values≤0.05. Results confirmed by polymorphism with a high number of singletons and haplotypes. This genetic variability can be explained by the fact that we had two different substrates but phenotypically very similar. The parameters of genetic differentiation, demographic and phylogenetic evolution revealed a weak genetic structuring of S. oryzae, populations in demographic expansion and poorly defined parental relationships between populations. This study provided further insight into the genetic characteristics of Sitophilus.