In Vitro Shoot Development of Eucalyptus citriodora on Rockwool in the Film Culture Vessel under CO₂ Enrichment

Abstract

An efficient system for growingin vitro plantlets ofEucalyptus citriodora Hook was developed. In the conventional closed system of culture with 2% sugar-containing gellan gum Murashige and Skoog (MS) medium supplemented with 0.02 mg/l indole-3-isobutyric acid, a serious defoliation of shoots was observed after three weeks. In contrast, plantlets grown on the sugar-free MS medium in the aerated bottle under 3,000 ppm CO₂ enriched condition did not show any defoliation. A marked enhanced growth of plantlets and no defoliation were observed on rockwool with the sugar-free liquid MS medium in the “Culture Pack”, made of fluorocarbon polymer film, under CO₂ enriched condition. CO₂ enrichment for this sugar-free “Culture Pack”-Rockwool system was also found to contribute to an improved growth of the plants in acclimatization.

Key words:

• CO₂ enrichment
• defoliation
• Eucalyptus citriodora
• micropropagation
• sugar-free medium