The Australian macadamia industry is hindered by inefficient clonal propagation methods, whereby varieties are grafted onto genetically variable seedling rootstocks with long lead-times for production. Tissue culture offers numerous benefits, including the mass production of high-quality, disease-free rootstocks that are genetically uniform and usually have vigorous root systems relative to cuttings. The aim of this research is to develop a high-throughput tissue culture propagation pipeline for Macadamia, to address current inefficiencies. The approach involves optimizing protocols for explant sterilization, shoot multiplication, elongation, root induction, and acclimatization across two rootstocks: ‘Beaumont’ and ‘H2’ and two scion varieties: ‘MCT1’ and ‘A203’. Significant progress has been made in sterilization and shoot multiplication for ‘Beaumont,’ and ‘MCT1’ with ongoing optimization for ‘A203’ and ‘H2.’ This hopes to support future trials of tissue-cultured clonal rootstocks and varieties on their own roots. In addition, in vitro micrografting will be explored to produce grafted trees in shortened timeframes with enhanced grafting efficiency and reduced losses. The genetic basis of rooting ability in Macadamia will also be investigated. These combined efforts aim to improve the sustainability, efficiency, and productivity of the Australian macadamia industry, ensuring a consistent supply of high-quality plants and supporting the industry's long-term growth and stability.
Hu et al. (Tue,) studied this question.