Propagation of Ornamental Plants
5(4): 186-191, 2005
ARTIFICIAL SEEDS FOR PROPAGATION OF DENDRANTHEMA X GRANDIFLORA (RAMAT.)
Ina Pinker* and Sayed Shehata Abdin Abdel-Rahman
Humboldt University of Berlin, Institute of Horticultural Sciences, Albrecht-Thaer-Weg 1, D-14195 Berlin, Germany, *Phone: ++49-30-31471163, *Fax: ++49-30-31471123, *E-mail: ina.pinker@agrar.hu-berlin.de
Abstract
Our experiments aimed to develop a method of encapsulation of Dendranthema nodal segments that can be used for non-sterile sowing. Shoot cultures of six genotypes of Dendranthema x grandiflora (Ramat.) were cultivated on modified MS medium and subcultured in 6-week-intervals. For encapsulation, 4- to 5-mm-long nodal segments were isolated 5 weeks after subculturing. Nodal segments were mixed with a liquid modified MS medium supplemented with 3% Na-alginate and hardened in 75 mM CaCl2. For sowing in non-sterile conditions, a second layer containing water, MS medium, 0.2 M mannitol, or 0.5 g l-1 activated charcoal, was added to the beads. In vitro water-agar, as well as sterilized perlite, vermiculite, and sand and gravel, were used as growing media. These mineral growing media were moistened with 7 ml deionized water with pH 5.8. For in vivo conversion non-sterilized perlite (average grain size = 2 mm) filled in 7-cm diameter pots was used. Up to 100% of the encapsulated nodal segments formed shoots and roots within 5 weeks of in vitro culture, provided that the beads contained MS medium and 1.0 mg l-1 indole-3-acetic acid. Approximately 50% of the beads without a second layer were contaminated in vivo. If the second layer contained MS medium the infection was similarly severe. A second layer of Ca-alginate with water reduced the contamination to 6.7% and shoot formation was recorded in 73% of the encapsulated nodal segments. Root formation occurred in 45% of the encapsulated segments. Up to 18% of the encapsulated segments died and up to 18% of the beads did not develop in vivo.
Key words: chrysanthemum, encapsulation, in vivo conversion, synthetic seeds.
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