Fig. 1.

Genome and sex determination evolution in Fragaria. The scenario for genome evolution is simplified and adapted from Tennessen et al. (2014, 2018), Liston et al. (2020), and Session and Rokhsar (2020). The number of polyploidization events is still debated (Tennessen et al. 2014; Session and Rokhsar 2020) and is depicted here as a single event for simplification. The colors of the branches correspond to the octoploid subgenomes and their diploid progenitors: Av (red), Bi (blue), B1 (yellow), and B2 (green). ⚥♂♀ illustrates the presence of hermaphrodite, male, and female individuals, respectively, in a species. The original male sterility trait was selected against through selective breeding (Liston et al. 2014) resulting in hermaphroditism in F. × ananassa which is represented by ⚥ *. Fragaria chiloensis is predominantly dioecious with some occurrence of hermaphrodite individuals (represented by a small ⚥  ) including subspecies sandwichensis which is only hermaphrodite (Staudt 1999). The group 6 homeologous chromosomes and location of the SDR are shown on the right for the octoploid clades.