In Vitro Rooting And Acclimatization Of Amelanchier Alnifolia (Nutt.) Nutt. Ex M. Roem: Testing Of Auxin, Spermidine, And Gibberellin For Overcoming Dormancy

BACKGROUND: Amelanchier alnifolia is an attractive small fruit difficult to propagate by traditional methods. Moreover, this species can be susceptible to dormancy after transplanting to the soil.OBJECTIVE: The aim of this work was to evaluate factors that contribute to effective in vitro rooting and acclimatization of micropropagated shoots of Amelanchier alnifolia.METHODS: Different auxins, media concentrations, and sprays containing plant growth regulators were tested. The experimental data were treated by analysis of variance.RESULTS: 1-naphthalene acetic acid (NAA) was superior for rooting compared to indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA). Cultivation of shoots on Murashige & Skoog (MS) medium with a half-strength concentration (1/2 MS) led to higher rooting frequencies than on full-strength MS medium. Addition of 1.5 mg l(-1) spermidine to cultivation medium did not significantly improve rooting. Gibberellic acid (GA(4+7)) alone or in combination with 6-benzylaminopurine (BAP) did not effectively break post-rooting dormancy.CONCLUSION: The greatest number of actively growing plants was recorded after rooting the shoots on 1/2 MS medium with 1 mg l(-1) NAA followed by a spray treatment with 1 mg l(-1) BAP. These results are directly applicable for improving rooting efficiency and acclimatization of micropropagated Amelanchier spp. plantlets.