Fig. 6

Diagram of sensitivity cycling to physical dormancy (PY) release for studied Cistaceae species. According to this model, PY break occurs in two steps, the first is a pre-conditioning step that softens the seeds and makes them sensitive to dormancy breaking, and the second, the actual dormancy-breaking step, during which seeds imbibe water. Seeds would not complete PY break if after the heat shock they are kept under inappropriate conditions for germination such as high summer temperatures. That is, the second step of PY break would not have been completed. A generalized model of dormancy-breaking requirements and sensitivity cycling in seeds with PY can be reviewed in Jayasuriya et al. (2009)