Endosymbiotic bacterial diversity associated with corn leaf aphid, Rhopalosiphum maidis Fitch (Hemiptera: Aphididae) populations under different maize management systems - preliminary study

In this study, a preliminary study was made to test the effect of host plant (maize, Zea mays) management on corn leaf aphid endosymbiotic bacterial diversity. A series of field assessments were run by collecting natural populations of corn leaf aphids from both traditionally managed (low-input) fields grown under high agricultural and natural landscape diversity and high- input agricultural fields with fertilizers, grown in monoculture under low natural landscape diversity. Bacterial total DNA sequencing was performed on an Illumina MiSeq platform. A total of 259,878 high-quality bacterial 16S rRNA gene sequences were obtained from the samples. In total, 213 bacterial genera were identified. A high abundance of primary symbionts (Buchnera sp.) and secondary symbionts (uncultured members of the family Enterobacteriaceae) were detected in all aphid samples. Other bacterial genera (Bacillus, Pseudomonas, Salipaludibacillus, Pantoea, Sphingomonas, and uncultured members of "Candidatus Moranbacteria" and "Candidatus, Falkowbacteria") were recorded, mostly from aphids collected from conventionally managed (high input) fields. The overall effect of high input treatment was such that 28% of the corn leaf aphid bacterial community distribution was affected. In contrast, low bacterial diversity was observed in corn leaf aphid populations from traditionally managed (low input) fields. These findings reveal the role of external environmental factors in governing the endosymbiotic bacterial community of aphids.