Germination requirements and cryopreservation tolerance of seeds of the endangered species Tuberaria major

The germination requirements and the cryopreservation tolerance of Tuberaria major (Cistaceae) seeds, an endangered plant species endemic from the Algarve region (South of Portugal) were studied. The final germination percentage of untreated seeds was very low (less than 2%) and was significantly improved by heat treatments (maximum of 54%). No significant differences were observed among the germination percentages reached by seeds submitted to boiling water or dry heat (100°C for different periods: 15, 30 and 60 min). Moreover, the temperature regime did not affect the final germination percentage. Cryopreservation did not affect the germination rate in comparison with the control, although the heat treatment was still necessary after cryopreservation. In conclusion, it was observed that heat stimulated germination of T. major seeds and cryopreservation could provide a method for long-term storage of germplasm of this endangered species.S. Gonçalves acknowledges a grant from Portuguese Science and Technology Foundation (FCT, Grant SFRH/BPD/31534/2006) and L. Fernandes acknowledges a grant for a Short Term Scientific Mission (COST 871-03576) from CryoPlanet Cost Action 871. This study was partially supported by the Project CGL2006-10536/BOS of the Ministerio de Educación y Ciencia, Spain