Long-Term Observation of In Vitro-Derived Malus Sylvestris (L.) Mill., the Path from the Bud to the Tree

The European wild apple (Malus sylvestris L.), a wild contributor to the domesticated apple, belongs to the endangered species in the Czech Republic. Thus, an efficient protocol was developed for in vitro plantlet regeneration using the post-dormant buds. The highest shoot induction was obtained on MS medium supplemented with 0.5 mg.l−1 BAP, 5 mg.l−1 GA and 0.1 mg.l−1 IBA. Shoot multiplication and elongation took place on the same medium with 0.2 mg.l−1 BAP and 0.1 mg.l−1 IBA. Indole-3-butyric acid at 0.5 mg.l−1 was most effective for rooting. The micropropagated plantlets were successfully acclimatized in greenhouse conditions and were transplanted into soil in forest. Finally, qualitative and quantitative parameters of tissue culture-derived plants were evaluated. Monitoring of in vitro plantings on experimental trials suggests that micropropagated wild apple trees retain the growth characteristics of generative individuals.