S04 - Session O1 - Micropropagation of Duboisia species via shoot tip meristem -

Authors: Yuxin Xue *, Jayeni Hiti Bandaralage, Dilani Jambuthenne Gamaralalage, Neena Mitter

Duboisia is an important Australian native medicinal plant that possesses a high content of scopolamine, a valuable tropane alkaloid with spasmolytic and mydriatic properties. Duboisia leaves as the sole commercial source of scopolamine are predominantly produced in Australia, industrial value equates to AU$100 million. Propagation of elite selections is one of the biggest challenges faced by this industry. Low germination rate and risk of genetic variation hinder bulk seed propagation, while the current propagation method via cuttings afflicted with low and inconsistent rooting. Furthermore, cutting propagation necessitates a considerable amount of plant materials, putting crop output at risk. F acing the issue of propagation dependency on cuttings, tissue culture is a cost-effective alternative for mass propagation of true-to-type elite Duboisia species from limited plant materials. In this context, the cultivation of shoot tip meristem and establishment of micropropagation protocol were studied for three Duboisia species: D. myoporoides , D. leichardtii and D. hopwoodii . A comparison of various nutrient media, hormone combinations and incubating conditions were tested to optimize meristem culture initiation, shoot multiplication, root formation and acclimatization. The findings revealed that tissue culture media composition and hormone requirements at different phases of meristem culture platform are genotype dependent for Duboisia species. This study for the first time demonstrated the in vitro micropropagation of Duboisia using shoot tip meristem , which led to higher multiplication rates and rooting percentages for all three Duboisia species, offering a sustainable and super-efficient propagation solution for the industry.