The influence of rootedness stimuli and rootedness substratum on rhizogenesis process for Magnolia kobus and Magnolia x soulangiana cuttings

摘要

The research concerning the influence of rootedness stimuli and rootedness substratum in rhizogenesis process for Magnolia X Soulangiana Soulange-Bodin and Magnolia kobus D.C. cuttings emphasize the key role of rootedness stimuli and the substratum for successfull propagation by shoot cuttings. The stimulation of rootedness to two species of Magnolia have been done by means of three phytohormones from auxines group: ANA (naftyl ? acetic acide) and IBA (indolil ? butyric acide) solution 0,005% concentration and Radistim powder. We used a rootedness substratum made of sand and peat mixture or sand and humus in various ratios. The tested cuttings both green cuttings (June) and half-lignified cuttings have been (August) treated with three phytohormones and planted in different substratum, in flower pots located in a hothouse with artificial fog installation. The root length, the rootedness percentage and the number of roots have been established for each cutting case. The cuttings which had not been treated with stimuli have no roots, the composition of the substratum influencing the quantity of roots rather than the rootedness percentage. These experiments were made in order to establish the optimate period for propagation by cuttings for the two studied species, the substratum composition with the best results and the rootedness stimulator which ensures the highest percentage of rootedness and the highest quantity of roots. These are very important aspects for industrial vegetative multiplication of Magnolia. Keyords: cutting, rhizogenesis, rootedness stimuli, rootedness substratum, Magnolia sp.