Articles
THE ORGAN CULTURE OF NODES OF FOUR SPECIES OF EUCALYPTUS
One is to culture nodes of adult trees and the second is to induce coppice formation from the base of adult trees and to culture this juvenile material.
Work with E. ficifolia (de Fossard and Bourne 1976) led to the culture of nodes from 36 year old trees with the formation of healthy shoots on a medium with six auxins.
Approximately three times more growth of the buds was obtained when 10μM IBA was used as the sole auxin source and best growth was obtained with 100μM Fe in place of 50μM Fe in the medium.
Although all seedling nodal cultures and subcultures were induced to form roots on cytokinin free media with 10μM IBA, so far adult nodal cultures have not been induced to form roots.
Nodes from coppiced E. grandis made good shoot growth and some root growth with only a little callus on a cytokinin free medium selected from the Broad Spectrum Experiment (de Fossard, Myint and Lee, 1974), whereas they made very strong root growth with abundant callus on the medium developed by Cresswell and Nitsch (1975). Excellent plantlets were obtained by combining the two media.
Nodes from adult trees of E. regnans and E. polybractea have produced healthy shoots on the medium developed for E. ficifolia.
Endogenous microbial contamination has been a serious problem with all forest collected material.