%0 Research article
%T Effect of indole-3-butyric acid on root formation in Alnus glutinosa microcuttings
%A San José, M. Carmen
%A Romero, Lourdes
%A Janeiro, Laura V.
%D 2012
%J Silva Fennica
%V 46
%N 5
%R doi:10.14214/sf.916
%U https://silvafennica.fi/article/916
%X A study of the in vitro rooting process in mature alder (Alnus glutinosa  (L.) Gaertn.) shoots is described. Microcuttings from shoots cultured  in vitro were transferred to a half-strength Woody Plant Medium  containing 0 or 0.1 mg l<sup>–1</sup> indole-3-butyric acid (IBA) for 0  to 7 days. The presence of IBA in the medium increased the rooting  percentage, number of roots, percentage of lateral roots, and length of  the shoots. Histological studies were carried out with shoots treated  with 0 or 0.1 mg l<sup>–1</sup> IBA for 7 days. According to these  criteria, treatment with IBA for 2–3 days proved to be the most  successful. In both treatments, substancial reactivation of cell  division was observed at the base of the shoots after 1 day. Some  cambial zone and adjacent phloem cells became dense cytoplasm, having  nuclei with prominent nucleoli. The first cell divisions were also  observed at this time. In the treatment with IBA (0.1 mg l<sup>–1</sup> for 7 days), meristemoids became individualized, consisting of densely  staining cells, by day 3. Identifiable conical shaped root primordia  with several cell layers were visible after 4–5 days. Roots with an  organized tissue system emerged from the stem after 6 days in the  IBA-treated shoots. Meristemoid formation was delayed until the fourth  day and root emergence until the eight day in the control treatment (no  IBA).