Use of the temporary immersion bioreactor system (RITA) for production of commercial Eucalyptus clones in Mondi Forests (SA)

• Published in: Plant cell, tissue and organ culture Vol. 81; no. 3; pp. 347 - 358
• Main Authors: McAlister, B, Finnie, J, Watt, M.P, Blakeway, F
• Format: Journal Article
• Language: English
• Published: 01.06.2005
• Subjects: benzyladenine; bioreactors; buds; clones; culture media; dose response; Eucalyptus; explants; forest trees; genetic variation; in vitro culture; in vitro regeneration; indole butyric acid; methodology; micropropagation; naphthaleneacetic acid; shoots; tissue culture; South Africa
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-004-6658-x

In order to optimise tissue culture systems and to meet production targets, Mondi Forests' biotechnology programme has in the last 2 years concentrated efforts on the use of the RITA temporary immersion bioreactor system. Protocols have been established for six Eucalyptus clones. Results indicate a four- to six-fold increase in yield, in half the time, with the RITA system when compared with axillary bud proliferation on semi-solid media. Furthermore, plants produced from the RITA system are hardier and acclimatize better, giving higher yields of hardened-off plants. The establishment of aseptic axillary shoots into the RITA system is from shoots in the semi-solid system. Highest multiplication was achieved using 30-second flushes of medium every 10 min, starting with 50 shoots per vessel. The multiplication cycles in RITA are between 14 and 18 days, compared with 25-28 days in a semi-solid system. There is minimal callus evident on the leaves and bases of the stems of plants in the RITA system and, in addition, cold-tolerant plants have a greater rooting competence when compared with plants coming from the semi-solid system. Ex vitro rooting of RITA - derived plantlets is substantially better than the plants from the semi-solid media.