Histological study of callus formation and optimization of cell growth in Taxus baccata.

Callus growth of Taxus baccata was optimized when Murashige and Skoog or B5 media were used with 2,4-D/kinetin ratios of 1:0.1, 2:0.1, and 5:0.1, when statistically equivalent results were obtained. A cell suspension culture was successfully achieved with a 3-fold increase in fresh weight after 40 days. Histological examination showed that in the leaf explants both the epidermis and mesophyll tissues divided to produce callus. In the stem explants callus formation was due to the cell division of the cortical parenchyma and of the cambium.