Micropropagation of white turmeric (Curcuma zedoaria (Christm.) Roscoe) and establishment of adventitious root culture for the production of phytochemicals

Curcuma zedoaria (Christm.) Roscoe (popular as “white turmeric”), a medicinal herb (Zingiberaceae family), is an integral part of traditional medicine and is also used as condiment and dye. Cultivation through conventional rhizome propagation is hindered by slow germination, long dormancy period, and susceptibility to diseases. The roots of C. zedoaria contain curcumin and curcumenol, but limited production of roots restricts sufficient production of these phytochemicals. Therefore, this study developed an innovative protocol for micropropagation and establishment of adventitious root culture in C. zedoaria for phytochemical production. For high-frequency multiple shoot production, Murashige and Skoog (MS) medium fortified with varying concentrations of 6-benzylaminopurine and meta-Topolin (mT) were tested. The maximum number of shoots were observed in MS medium + 1.5 mg/L mT that yielded an average of 620 shoots from a single explant after 36 weeks following 6 subcultures. The maximum number of roots were produced in MS medium + 1.5 mg/L indole-3-butyric acid. An 86 % survival was obtained by acclimatizing the plants in soil and rice husk (3:1) media. The genetic stability of the plants was substantiated with the aid of four different types of molecular markers coupled with flow cytometry. The highest adventitious root induction frequency (100 %) was recorded in 1.5 mg/L α-naphthalene acetic acid. MS medium at ¼ strength was ideal for the proliferation of roots as well as the accumulation of phytochemicals. Eliciting the adventitious root culture with 400 µM methyl jasmonate further improved the phytochemical content. Therefore, the protocol described in this study can be utilized to produce genetically identical C. zedoaria plants at a larger quantity and to generate adventitious roots that can be used as an alternate source of phytochemicals. [Display omitted] •Curcuma zedoaria used as a traditional medicine, condiment, and dye.•Protocol for micropropagation and adventitious root culture for phytochemical production.•620 shoots were observed in MS + 1.5 mg/L mT at the end of 36 weeks and 6 subcultures.•Stability confirmed using four different types of molecular markers and flow cytometry.•¼MS + 1.5 mg/L NAA + 400 µM MeJ ideal for root proliferation and phytochemicals accumulation.