Patterns of Genome-Wide Variation, Population Differentiation and SNP Discovery of the Red Banded Stink Bug (Piezodorus guildinii)

Abstract

Unravelling the details of range expansion and ecological dominance shifts of insect pests has been challenging due to the lack of basic knowledge about population structure, gene flow, and most importantly, how natural selection is affecting the adaptive process. Piezodous guildinii is an emerging pest of soybean in the southern region of the United States, and increasingly important in Brazil in recent years. However, the reasons P. guildinii is gradually becoming more of a problem are questions still mostly unanswered. Here, we have genotyped P. guildinii samples and discovered 1,337 loci containing 4,083 variant sites SNPs that were used to estimate genetic structure and to identify gene candidates under natural selection. Our results revealed the existence of a significant genetic structure separating populations according to their broad geographic origin, i.e., U.S. and Brazil, supported by AMOVA (FGT = 0.26), STRUCTURE, PCA, and FST analyses. High levels of gene flow or coancestry within groups (i.e., within countries) can be inferred from the data, and no spatial pattern was apparent at the finer scale in Brazil. Samples from different seasons show more heterogeneous compositions suggesting mixed ancestry and a more complex dynamic. Lastly, we were able to detect and successfully annotated 123 GBS loci (10.5%) under positive selection. The gene ontology (GO) analysis implicated candidate genes under selection with genome reorganization, neuropeptides, and energy mobilization. We discuss how these findings could be related to recent outbreaks and suggest how new efforts directed to better understand P. guildinii population dynamics.

Characterization and Comparison of Intestinal Bacterial Microbiomes of Euschistus heros and Piezodorus guildinii Collected in Brazil and the United States

“…We found that P. guildinii displayed a higher intestinal bacterial diversity from Brazil than the United States, which might be mainly explained by genetic and environmental factors. For genetic factors, Zucchi et al (2019a) evidenced distinct P. guildinii lineages from Brazil and the United States using Genotype-By-Sequencing. These genetic differences in stink bug lineages might account for the differences in the intestinal microbiome changing the physicochemical conditions of the intestine and, consequently, the microbial composition of the different lineages.…”

Characterization and Comparison of Intestinal Bacterial Microbiomes of Euschistus Heros and Piezodorus Guildinii Collected in Brazil and the United States

“…We found that P. guildinii displayed a higher intestinal bacterial diversity from Brazil than the US, which might be explained mainly by genetic and environmental factors. For genetic factors, Zucchi et al [45] evidenced distinct P. guildinii lineages from Brazil and the United States using Genotype-By-Sequencing. These genetic differences in stink bug lineages might account for the differences in the intestinal microbiome.…”

Chromosome length genome assembly of the redbanded stink bug, Piezodorus guildinii (Westwood).

“…Molecular resources currently available for RBSB in public databases are limited to 107 microsatellite sequences, six partial cytochrome oxidase I (COI) subunit sequences [25] and 17 Gbp of genotype by sequencing (GBS) data in the NCBI sequence read archive [14]. Transcriptome, genome or proteome data are not available for this species.…”

“…Resistance to insecticides in RBSB has been documented but the genetic basis of the insecticide resistance in this insect is not well understood. So far, only one population genetic study has been carried out on this species using 1,337 SNP markers [14] to estimate genetic structure and to identify loci under natural selection. This study identi ed the presence of genetic structure separating populations in USA and Brazil.…”