*4.5. Principal Component Analysis*

A principal component analysis (PCA) was performed on the log−2-transformed response ratios (ΔP) using the prcomp function as implemented in R (https://www.r-project.org/).

## *4.6. Genomic Distances*

Genomic distances between accessions were computed as Kimura distances using the program dnadist (v3.698, [37]). Genomic sequences of all accessions were taken as those composed of the 178,083 sites that were detected polymorphic in at least one of the 36 accessions. Original sequences were taken from [38] with exception of the sequence information of accession PHW-34, which was not included in the set, and was taken from [35].
