Germination and dormancy breaking in the endemic juniper (Juniperus thurifera L.) of Algeria: an evaluation of acceleration techniques

ABSTRACT Juniper forests (Juniperus thurifera L.) are among the most valuable forest ecosystems in the mountains of Algeria. Numerous studies have focused on enhancing the germination capacity of juniper seeds. This particular study aimed at breaking the seed dormancy by employing pretreatment methods involving sulphuric acid and gibberellic acid (AG3). To distinguish viable seeds from non-viable ones, the seeds were submerged in sucrose solutions with increasing concentrations (0%. 20%. 40%. and 60%) and subjected to cold treatments at 4 °C for a period of 2 years. Additionally, two pre-treatments were conducted: the first involved immersing the seeds in concentrated sulphuric acid for 15 minutes, while the second pre-treatment utilized AG3 at various concentrations (100 ppm, 400 ppm, and 1000 ppm) for 24 and 48 hours. The results demonstrated the possibility of breaking seed dormancy and achieving germination, which varied significantly based on the pretreatments, seed fractions, cold treatment, and their interactions. The highest germination percentage (83.33%) was observed when applying the gibberellic acid pretreatment (400 ppm for 48hours) to the seeds of the heavy fraction previously stored in cold conditions. Overall, this research opens up new possibilities for effectively managing and protecting juniper forests, contributing to their long-term sustainability and conservation efforts.