Anatomical and biochemical changes during adventitious rooting of apple rootstocks MM 106 cultured in vitro

Abstract

Adventitious rooting in microcuttings of Malus rootstocks MM106 was studied as regards their histological and biochemical aspects. Microcuttings from shoots raised in Murashige and Skoog's (1962) medium were transferred into a rooting medium containing IBA in the dark, then fixed 0, 3, 5, 7 and 10 days after. Some cambial zone and adjacent phloem cells became dense cytoplasm, nuclei with prominent nucleoli and the first cell divisions were observed at day 3. Meristemoids became individualized, consisting of densely staining cells (with enlarged nucleoli) formed outside the xylem by day 5. Identifiable root primordia with a conical shape and several cell layers were present at day 7. Roots with organized tissue system emerged from the stem 10 days after the root induction treatment. From these histological observations, it can be established that the rooting induction stage ended before day 3. The initiation stage, with the first histological modifications to the formation of meristemoids, would correspond to the transient increase of our biochemical marker (peroxidase activity) until day 5. The best rooting percentage obtained with cultures in the presence of auxin during 5 days confirms this hypothesis. The expression of rooting can then take place.

Can Changes in Starch Content and Peroxidase Activity Be Used as Rooting Phase Markers for Rhododendron Leaf Bud Cuttings?

“…The next adventitious root initial formation and development of root primordia occurred in the expression phase simultaneously. Similar findings have been reported for microcuttings of Malus rootstock MM 106 (Naija et al, 2008) where initiation and development of adventitious roots were not synchronous and different stages of adventitious root development were observed at the same time in single pieces of stem.…”

“…Peroxidase activity has been used to define rooting phases (induction, initiation and expression) (Gaspar et al, 1994) in several species: Elaeis guineensis (Rival et al, 1997), Psoralea corylifolia (Rout et al, 2000), Arbutus unedo and Taxus baccata (Metaxas et al, 2004), Ebenus cretica , Gardenia jasminoides (Hatzilazarou et al, 2006) and Malus rootstock MM 106 (Naija et al, 2008). In our work the pattern of change in peroxidase activity was similar in the stem bases and leaves of IBAleaf bud cuttings of elepidote rhododendron.…”

“…These phases have been identified through variation of some biochemical markers. At present, peroxidase is asserted to be the best rooting phase marker for rooting of cuttings (Gaspar et al, 1992;Arena et al, 2003;Metaxas et al, 2004;Syros et al, 2004;Naija et al, 2008;). The induction phase of rooting, before any visible morphological and histological events, is characterized by a decline in peroxidase activity, and the minimum of peroxidase activity indicates termination of this phase.…”

Rooting of Stem Cuttings with Different Indole 3 Butyric Acid (IBA) Treatments and Development of Micropropagation Protocol for <i>Piper betle</i> L. Node Culture

“…, dehydrated consistent with [22]) and [23], via a graded n-butanol series and embedded in paraffin n wax. Sections of 8 -10 μm were cut and stained Safranin 0-fast green (FCF) for the general examination [24].…”

Effect of indole-3-butyric acid on root formation in Alnus glutinosa microcuttings

“…Most woody plants require a sequence of two rooting media. Thus, Naija et al (2008) found that a period of 5 days in rooting medium with IBA was sufficient to induce 97% rooting in microcuttings of Malus × domestica Borkh. rootstock MM 106, and the exposure to IBA for periods longer than five days produced undesirable side effects on shoots, such as callus formation and leaf necrosis.…”