Abstract
BackgroundLeptospermum scoparium J.R.Forst. & G.Forst. is highly valued for the production of antimicrobial honey. Both researchers and the Australian honey industry are interested in the clonal propagation of these plants to be used for experiments and plantation establishment. However, little information is available on clonal propagation by cuttings. Here we sought to develop a detailed method for L. scoparium propagation by semi-hardwood cuttings by testing the influence of genotype and auxin (indole butyric acid (IBA) and IBA + naphthalene acetic acid (NAA)) concentration on plants originating from four natural populations in Victoria, Australia. ResultsThere was no significant difference in root induction, which ranged from 50.9 – 68.0%, in the four clonal source plants selected. The application of 3 g/L IBA increased root induction from 46.6% of the control cuttings to 77.6% of treated cuttings and stimulated longer roots. The application of 8 g/L IBA increased leaf fall, the presence of necrosis, from 22.5% on the controls to 82.8% on dipped cuttings, and cutting death.Although there was no significant difference in root induction, cuttings that were ‘watered-in’ after planting dropped significantly fewer leaves and had significantly lower rates of necrosis than cuttings watered in after 2-3 days. It was also found that the maturity stage of semi-hardwood cuttings did not significantly affect any of the variables measured. Transplant survival ranged from 78.1 – 89.0% for cuttings treated with auxin and 77.3 to 92.2% for the four clonal source plants. ConclusionThis study found that the clonal source plants selected did not affect the success of propagation. Overall for maximum success, semi-hardwood cuttings can be collected from the current or previous seasons growth, be treated with 3 g/L IBA gel, ‘watered in’ and placed into a propagation tent for approximately six weeks. Cuttings that form roots will transplant easily with high transplant survival.
Development of a robust method for propagation of Leptospermum scoparium J.R.Forst. & G.Forst. from semi-hardwood cuttings
