Callogenesis of Betula pendula Roth. via tissue culture of different explants and media

Birch (Betula pendula Roth.) is one of the most important species exposed to extinction due to the limited natural habitat and lack of regeneration. Plant tissue culture technique is an appropriate solution for asexual reproduction of this species and to protect it in controlled conditions. In this research, callogenesis of B. pendula was investigated using five types of explants (leave, stem, nodal, petiole and bark) in WPM and NT media enriched with two hormonal combinations including A) 1mg/l BAP, 0.1 mg/l 2,4-D and B) 0.1 mg/l BAP, 0.01mg/l TDZ). The results indicated that the minimum callogenesis was observed in nodal and petiole explants in NT medium enriched with A hormonal combination. Callogenesis, fresh and dry weight of bark, stem and leave explants were significantly decreased in WPM and NT media containing B hormonal combination as compared with A hormonal combination. The maximum callogenesis was observed in bark explant in WPM (81.14) and NT (70.36) media with A hormonal combination as compared with other explants. The average fresh and dry weight of this explant in NT medium was more than that of WPM medium with the same hormonal combination.