Figure 3. Principal component analysis (PCA) of the gourd's genome SNP data at >9× coverage and compared to European individuals of the 1000 Genomes Project.

The analysis was based on 47 randomly selected individuals per population (FINS, CEU, GBR, TSI), except for the Iberians, where all six available individuals were included. A total of 32,701 SNPs were included after filtering for heterozygous positions in order to account for the background contamination.