Composition of the whiteflies microbiome in populations with and without insecticide applications in Yucatan Mexico

Abstract

The whitefly Bemisia tabaci (Gennadius) has coevolved with intracellular endosymbiotic bacteria that help supplement their nutrient-poor diets with essential amino acids and carotenoids; however the type of host species and the agricultural practices can influence the composition of the endosymbiotic bacterial community. In this study, the main goal was to explore the diversity of endosymbiont communities in whitefly populations growing in peppers (Capsicum chinense Jacq. under greenhouse and Capsicum annuum L. backyard) exposed to chemical insecticides (treatment MB1) and non-exposed (treatment MB2). The whiteflies were identified through phylogenetic analysis of the mitochondrial Cytochrome Oxidase I gene sequences. Bacterial endosymbionts were characterized by high-throughput sequencing of the V3 region of the 16S rRNA gene, which amplifies a fragment of around 180 bp. Sequence analysis yielded in MB1 eight Phylum, nine classes, 30 orders, 35 families, 64 genera, and 20 species, while in MB2 it was obtained eight Phylum, 11 classes, 26 orders, 37 families, 61 genera, and 18 species. The most abundant phylum in the two samples analyzed was Proteobacteria followed by Chlamydiae and Bacteroidetes. The phyla that presented the greatest taxonomic diversity of bacteria at the genus level in both samples were Proteobacteria, Actinobacteria and Firmicutes. According to the evaluated alpha diversity indices, low richness and diversity were obtained in the two samples, but when comparing the two samples, MB2 showed the greatest richness and diversity with 1,698 with the Shannon index.. The results obtained are a first approximation to describe the impact of insecticides used on peppers on the diversity and richness of whitefly endosymbiotic bacteria.