Phalaenopsis amabilis, commonly known in Indonesia as 'Anggrek Bulan' is one of the Orchidaceae species typically having large (7-12 cm), pure white flowers with yellow coloration and some red stripes on its labellum (Handoyo, 2010). Based on their perianth morphology, there are six types of Phal. amabilis, such as Taiwan, Sumatera, Irian Jaya, Java, Borneo, and Grandiflora types. The Phal. amabilis from Sumatera has smaller perianth than those from Java and Borneo while Phal. grandiflora from Borneo is characterized as having the largest flower and more than 5 cm petals (Ikedo, n.d.). As in many orchid species, illegal harvest, forest destruction, and climatic changes may contribute to the decline of their natural populations (Crain & Tremblay, 2014; Crain & Tremblay, 2017; Fay, 2018). Therefore, it is necessary to develop concerted efforts for ex situ conservation of endangered orchid species before it becomes extinct. The development of ex-situ conservation requires the use of tissue culture as the alternative technology for clonal propagation (Merritt, Hay, Swarts, Sommerville, & Dixon, 2014). Various tissues and organs have been used as explants to initiate propagation of Phalaenopsis, such as leaf (Balilashaki, Naderi, Kalantari,
