In vitro callus and shoot organogenesis from leaf and stem explants of Chamaedaphne calyculata

Leatherleaf Chamaedaphne calyculata (L) Moench is a relict, rare and endangered species in Poland. There are no reports on the micropropagation of Chamaedaphne calyculata in the literature. Therefore, the aim of this study was to propose a propagation protocol for leatherleaf via indirect organogenesis using leaves and stems (internodal segments) derived from mature plants growing in a natural stand and from plants grown in vitro as explants. The medium developed by Anthony et al. (2004) with 100%, 50% and 25% salt concentrations, supplemented with IAA (5 and 10 mu M) and TDZ (5 and 10 mu M), was used for callus development and the induction of adventitious shoots. The media developed by Anthony et al. (2004) and Anderson (1980), both containing 10 mu M TDZ and 5 mu M IAA or 2.28 mu M zeatin, were used for adventitious shoot elongation. Secondary explants proved to be the most effective starting material for callus induction, the regeneration and elongation of adventitious shoots. The most supportive medium for callus induction and growth and the induction of adventitious shoots was the full medium proposed by Anthony et al. (2004) containing 5 mu M IAA and 10 mu M TDZ. Anderson's (1980) medium containing 2.28 mu M zeatin delivered optimal results in the elongation of adventitious shoots of Ch. calyculata. Roots were cultivated on Anderson's (1980) phytohormone-free medium. Approximately 65% of the plantlets survived after transfer to the sphagnum-peat and perlite mixture (3:1). The plants grew normally without any signs of morphological variation. This study makes the first ever attempt to propose an effective micropropagation protocol for Ch. calyculata.