Macronutrients Effect on Secondary Somatic Embryogenesis of Moroccan Cork Oak (Quercus suber L.)

To define the preliminary embryogenesis culture conditions of Moroccan Cork Oak (Quercus suber L.) in secondary propagation systems, secondary embryos formation from primary embryos were analyzed using seven macronutrient medias: (Chalupa) (BTM), Murashige and Skoog (MS), Schenk and Hildebrant (SH), Schenk and Hildebrant with half content macronutrients (SH ), full Gam-borg (G), Margara (N30K) and Woody Plant Media(WPM). Mature primary embryos at cotyledonal stage of 8- 10 mm, were placed in each culture medium, and supplemented with 30 g/l of glucose and 7 g/l of agar without PGR. The experimental design consisted of a Petri dish containing three embryos explants. Each one of the seven treatments was composed of ten Petri dishes. Mean number of secondary somatic embryos, clusters and new embryogenic formation on clusters were recorded after 8 weeks, and evaluated by statistical analysis. There were no significant differences (p ≤ 0.05) in clusters and new embryos on clusters formation among evaluated media; but mean number of secondary embryos was significantly higher in N30K (4.37 ± 0.48) compared with con-trol media (1.37 ± 0.15). The morphology of secondary embryos grown in the N30K medium exclu-sively showed the presence of three embryogenic stages: early cotyledonal with translucide as