The aim of the performed investigations was to determine which part of the embryo has the optimal properties for callus induction at low concentrations of 2,4-D (2 mgdm-3). The explants were cut along or across the embryo axis into 2, 3, 4 fragments and cultured on the Murashige and Skoog medium for 6 weeks. It was found that callus derived from mature embryos (dry seeds) is characterised by comparable fresh and dry mass and by similar changes in size of the cells with fragments derived from mature embryos (but before the dormant) and from immature embryos. Essential difference was observed in the germination ability of the explants. The percentage of germination of mature embryo fragments was the lowest. It was demonstrated that despite of the embryo type, fragments originating from its central part appeared the most suitable for in vitro culture. In the case of these fragments the highest increase of the fresh mass of callus tissue, optimal morphological features and the appearance of meristematic centres were observed.