Fig 1.
Fall armyworm sampling locations in Brazil and Argentina according to ecoregions.
Shapefile of limits of countries in South America: IBGE-Mapas (IBGE—Brazilian Institute of Geography and Statistics; Available at: <https://geoftp.ibge.gov.br/cartas_e_mapas/bases_cartograficas_continuas/bc250/versao2021/shapefile/bc250_shapefile_2021_11_18.zip>; Acessed on February 26, 2023) QGIS v3.28.3 (Available at: <https://qgis.org/en/site/>; Acessed on: February 26, 2023). DATUM: SIRGAS 2000.
Table 1.
Fall armyworm (Spodoptera frugiperda) sampling information.
N refers to the number of samples successfully sequenced after GBS processing, totaling 228 individuals.
Fig 2.
Haplotype frequencies in fall armyworm populations of Brazil and Argentina using COI and Tpi markers.
A) COI strains COI-RS (R-strain) and COI-CS (C-strain) B) Tpi marker identifies R-strain (TpiR), C-strain (TpiC), and hybrids (TpiH) that feature both diagnostic polymorphisms at site gTpi183.
Fig 3.
Genetic structure of FAW populations from Brazil and Argentina based on 3309 SNP loci.
(A) Heatmap and dendrogram based on FST pairwise distances among 15 locations. Red color represents a greater degree of differentiation. (B) Principal Component Analysis (PCA) showing the first two components. Geographic locations are represented by different colors, and dots represent different individuals.
Fig 4.
PCA analysis generated with (A) 2,853 neutral SNPs, (B) 456 outliers.
Dots represent different individuals of each location.
Fig 5.
Admixture analysis of fall armyworm populations based on (A) 2,853 neutral SNP loci and (B) 456 outlier SNP loci.
Bar plot colors indicate estimated proportions of ancestry for each individual shown as a vertical line.
Fig 6.
Outlier SNPs under positive selection using Pcadapt, FstHet, and FLK.
(A) GO categories of putative loci under selection generated from WEGO. The results are presented in three main categories: biological process, cellular component, and molecular function. The left y-axis indicates the percentage of a specific category of genes in the main category. The right y-axis indicates the number of genes in each category. (B) Manhattan plot of FST analysis comparing C-strain and R-strain against the position of SNPs on each of the 31 chromosomes. Chromosome 1 corresponds to the sex chromosome Z. Each SNP is represented by a dot. Chromosomes are represented by blue (odd) and orange (even).