Hedychium longicornutum Griff. ex Baker is a Zingiberaceous plant that has been used for traditional medicines and ornamental purposes. Though this plant is a vulnerable plant of Thailand, it has a high potential to be promoted as a new economic ornamental plant due to its exotic inflorescences. However, the usage of this valuable plant on a large scale is restricted since the population of H. longicornutum in natural habitat is limited. This current study established a micropropagation protocol to ensure sustainable use of this plant for commercial and conservation purposes. In vitro axenic plants of H. longicornutum were initiated from seeds. Optimum shoot multiplication medium was evaluated by culturing leafy-shoot bases on Murashige and Skoog’s (MS) medium supplemented with 0-35 µM of N6-benzyladenine (BA) or thidiazuron (TDZ). BA supplemented media were better than those TDZ media since no abnormalities of shoot morphology, shoot elongation, and root regeneration were found. MS supplemented with 15 µM BA was revealed to be the most effective medium for shoot multiplication (9.75 leafy-shoots/explant with 9.54 cm height). Regenerated shoots spontaneously rooted on MS medium. The in vitro raised plants were successfully grown ex vitro and showed the highest survival rate (100%) on planting substrate consisting of 2 garden soil mixture: 1 smashed charcoal. The genetic fidelity of the micropropagated plants compared with mother plants grown in the field was assessed by random amplified polymorphic DNA (RAPD) technique. The results consistently demonstrated the genetic uniformity of the regenerants. This is the first report of an established in vitro true-to-true type propagation in H. longicornutum.
Keywords: Zingiberaceae; micropropagation; cytokinin; direct organogenesis; genetic fidelity
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E-mail: ngarmnij.chu@mahidol.edu
