Authors:

Abstract

Conventionally, turmeric (Curcuma longa L.) is propagated through rhizomes. However, its multiplication rate is very low where a single turmeric rhizome approximately produces 6-8 lateral buds and nearly 20-25% of the harvest should be retained as planting materials for the next season. Therefore, the study focuses on the development of an in vitro regeneration protocol of turmeric for the year-round provision of disease-free planting material. Commercially grown sprouted rhizome buds were surface sterilized with fungicide followed by 70% ethanol, and with different concentrations of Clorox (10, 20, 30 and 40%). Different exposure times (5, 10, 15 and 20 minutes) were tested to develop the best sterilization procedure. MS medium supplemented with different concentrations of hormones BAP (2.0, 3.0, 4.0 and 5.0 mg/l) and NAA (0.25 and 0.5 mg/l) for shoot regeneration, and IBA (1.0, 2.0, 3.0 and 4.0 mg/l) for root regeneration to find the best combination. The results showed that 30% Clorox and 20 minutes exposure time is suitable for surface sterilization of buds about 1.5-2.0 cm long. Shoot regeneration was the highest when the media were treated with 4.0 mg/l of BAP and 0.5 mg/l NAA. The best IBA concentration that gives the highest number of roots in the least number of weeks is 2.0mg/l. Additionally, 58.33% of the plantlets survived after field acclimatization. The study concluded that the protocol can be used for in vitro propagation of turmeric using rhizome buds for large-scale production of plant materials.

Keywords: Curcuma longa L., In vitro propagation, Root regeneration, Shoot regeneration, Sterilization