Tissue culture of gerunggang (Cratoxylum arborescens (Vahl) Blume): multipurpose native species of Indonesian peatland

Abstract Gerunggang (Cratoxylum arborescens (Vahl) Blume) is a tree native to Indonesian peatlands that has great potential as an alternative fiber-producing species for the pulp and paper industry because it is adaptable and does not have the potential to disrupt local ecosystems. The species also contains important anti-cancer compounds for the pharmaceutical industry. These industries require large quantities of raw materials to meet their needs, which cannot be met by the supply of conventional plant seedlings. Tissue culture is one of the propagation biotechnologies that can be used as an alternative to provide more efficient germplasm. In this study, we developed a protocol for gerunggang propagation using tissue culture technique. The results showed that the combination of 1 mg/l 6-benzylamino purine (BAP) and 0.5 mg/l naphthalene acetic acid (NAA) in Murashige & Skoog media provided the fastest bud break time (2 weeks before the first subculture), with the highest shoot initiation (3.0 ± 0.2 cm), and after 4 weeks of incubation, the highest auxiliary shoot elongation (7.4 ± 0.1 cm). The significant effect of this hormone concentration also increases the nodule multiplication coefficient (NMC), which is 7.5. In vitro root response on the same propagation medium showed good growth with an average root length of 4.8 ± 0.2 cm. Acclimatization of plantlets was successful under ex vitro conditions and resulted in good growth after 2 and 3 months in the greenhouse. The advantage of applying the tissue culture method to gerunggang is that it can produce about seven times more seedlings from one explant in about 4 weeks. These results will be very useful for further research in the field and require a more intensive and comprehensive study.