Fig 1. Stages of olive flower development corresponding to the sampling dates.

The sampling period includes the differentiation of flower clusters from inflorescence buds and the subsequent stages until the anther dehiscence of the developed flowers. Pictures of entire flower clusters (below) and single flower buds (above) are shown. Stages 1–6: developing flowers at pre-anthesis (26 to 3 days before anthesis). Stages 7–10: flowers at anthesis (0 to 3 days after anthesis). Stages b1-b3 represent the inflorescence buds collected at 42, 36 and 32 days before anthesis and were only used for the RT-qPCR experiments on the candidate homeotic genes.