XVI International Botanical Congess

Calli of Taxus baccata were induced using different tissue explants including the green arils, young stems and leaves. The optimal medium composition for callus culture was B5, supplemented with 10 g/l sucrose, 7 g/l agar, 2 mg/l 2,4-D and 0.2 mg/l kin. Initiation of callusing occured within 17-20 days. For 21-25 days cell mass (fresh weight) increased 3-5 times as much. Obtained calli were comparatively homogeneous, friable, pale-yellow. It was established that the initiation of cell proliferation was localized in the epidermal and mesophyll cells of leaves and in the parenchymatous and cambial layer of young stems. Histological study of calli revealed the presence of parenchymatous thin-walled cells with different shapes and sizes.