Phylogeny of the central 2.7 kb of the hemizygous SDR cassette (blue box, Fig 2; 0%–30% missing data; mean = 16%) from females of several octoploid strawberries (S1 Table). Three major clades, α, β, and γ, are revealed. Shimodaira-Hasegawa-like (black, above branches) and bootstrap (grey, below branches) support is shown if >50%. SDRs that have been mapped are noted along with the location of the SDR. A pseudo-outgroup sequence (not shown) was generated with consistent homology to the W haplotype along this 2.7 kb portion, by concatenation of sequence from F. vesca reference genome Fvb6 position 1 Mb and orthologous Z chromosome BAC sequence, together with 1.2 kb of sequence from Fvb7 position 18 Mb corresponding to the closest autosomal paralog of RPP0W. The close evolutionary relationship between the β and γ clades is consistent with the inferred history of translocations, indicated at two points with black curved arrows to the left of the phylogeny. BAC, bacterial artificial chromosome; Fac, F. × ananassa ssp. cuneifolia; Fc, F. chiloensis; Fvb, diploid reference genome assembly informed by F. vesca ssp. bracteata; Fvg, F. virginiana ssp. glauca; Fvp, F. virginiana ssp. platypetala; Fvv, F. virginiana ssp. virginiana; Mb, megabase; SDR, sex-determining region.