Table 1.
List and origin of 599 B. maritima accessions used in the current study with their putative geographic regions.
Fig 1.
Distribution and density of single nucleotide polymorphisms (SNPs) across nine chromosomes (A) and average linkage disequilibrium (LD) decay (B) in the collection of 599 Beta maritima accessions and 30 cultivated beet lines.
Fig 2.
Phylogenetic tree developed from 599 Beta maritima accessions and 30 cultivated beet lines using SNPs covering the whole genome.
The red lines in the cluster clades indicate the cultivated beet lines.
Table 2.
Distribution of Beta maritima accessions in two distinct phylogenetic clusters defined by phylogenetic analysis using B. maritima collection and 30 cultivated beet lines.
Fig 3.
The plot of K versus ΔK for determination of the optimum number of subpopulations within 599 B. maritima accessions.
Optimal subpopulations are equal to K values with maximal ΔK values. Data was generated using the computer program STRUCTURE v2.3.4.
Fig 4.
Genetic structure of the 599 B. maritima accessions and 30 cultivated beet lines analyzed using DAPC (discriminant analysis of principal components) methodology.
A. Genetic relationships amongst clusters. The length of bars for each cluster indicates variations within each cluster. Bars in different color correspond to different clusters. B. Geographic distribution of clusters defined by DAPC method. The geographic map is based on NASA world map (https://data.nasa.gov/). Detailed list of accessions in each cluster is available in Tables 3 and S1. Location of Cluster 6 is not shown since it is mainly corresponding to worldwide collected cultivated beet lines.
Table 3.
Distribution of Beta maritima accessions in eight clusters as defined by DAPC (discriminant analysis of principal components) methodology across all collection regionsa.
Table 4.
Genetic diversity among subpopulations represented by fixation index (Fst) and Nei’s genetic distance estimated using a worldwide collection of 599 Beta maritima accessions with 30 cultivated beet lines a.
Fig 5.
Major allele frequency distribution on each chromosome across all clusters defined by DAPC (discriminant analysis of principal components) methodology.
Red rectangular boxes with dashed lines indicate genomic regions with a higher level of variation among clusters, and the regions were determined by the above 75th percentile of the major allele frequency variance.
Table 5.
Population genetic indices estimated within each cluster (subpopulation) as defined by DAPC (discriminant analysis of principal components) methodology in 599 Beta maritima accessions and 30 cultivated beet lines.