Germination responses of Erica andevalensis to different chemical and physical treatments

7 pages, 4 figures, 1 table.-- Available online Aug 12, 2008.Erica andevalensis Cabezudo & Rivera is a threatened edaphic endemic species of Andalusia (SW Spain). Under natural conditions, the plants produce a very large number of small seeds (0.3–0.4 mm) but very few seedlings survive. Different treatments (high temperature, cold pre-treatment, nitrogen salts, and gibberellic acid applications) were tested to assess germination patterns in different populations and to determinate the most favorable conditions for germination. Gibberellic acid was provided in five different concentrations from 0 to 400 ppm GA3, while nitrogen was applied as 10 mM of either KNO3 or NH4NO3. The effect of pH on germination was also tested. The species always showed a low germination rate (6.50–22%) that was not stimulated either by 1 or 4 months in dry cold pre-treatment, nitrogen application, acid pH medium, or by high temperature (80°C for 10 min); although gibberellic acid application (100–400 ppm) significantly enhanced germination. The highest percentage of germination (41.6%) was achieved with a mean germination time to start germination (t-0) of 7.6 ± 0.54 days when the seeds were subjected to 400 ppm gibberellic acid treatment. The population origin did not have a significant effect on germination percentage.The present research was supported in part by the Spanish Ministry of Science and Education (CGL2006/02860) and in part by Fundación Areces (Proyect title: Mecanismos de resistencia a metales pesados en especies significativas de la cuenca minera de Riotinto).Peer reviewe