Tissue culture and macadamia propagation

Macadamia is a highly valued nut tree crop. Plant propagation via tissue culture is a powerful tool for faster multiplication of plants. The application of tissue culture in macadamia propagation would be valuable in facilitating quicker multiplication of new rootstock and scion varieties. The aim of our study is to develop tissue culture technology for macadamia. In vitro cultures were established using single node segments. Inclusion of 2 mg l(-1) BA (6-benzylaminopurine) in the medium produced the highest percentage bud break, mean shoot numbers per explant and shoot length. Levels above 2 mg l(-1) BA in the medium produced stunted and vitreous shoots. Combining 2 mg l(-1) BA with gibberellic acid in the medium further improved bud break, shoot number and shoot length significantly from explants. Highest shoot numbers and shoot length were achieved in the medium containing 1 mg l(-1) GA(3) + 2 mg l(-1) BA. Regenerated shoots were rooted in medium containing IBA. In vitro propagated plants were successfully transferred to glasshouse conditions.