highly significantP = 0.01
To allow us to analyse data for all 20 study provenances, we used the highly significant relationship between F ST and geographic distance for the 17 provenances (Mantel test in the adegenet r package, P = 0.01 with 999 iterations) to estimate a pseudo- F ST for the full set of 20 provenances, referred to hereafter as GeoF ST (full details are given in Data S2 ).