Optimization of α-naphthalene acetic acid and 6-benzylaminopurine Concentrations for the in vitro micropropagation of Discorea bulbifera Linn

Abstract

One of the 600 species of the Dioscoreaceae family that have been used in traditional medicine all over the world is Dioscorea bulbifera. It is known as bitter yam and is indigenous to Asia, tropical Africa, America, and northern Australia. This herbaceous climbing plant has been used to treat various diseases including diabetes and ulcers. In order to improve and conserve this important medicinal plant, growth responses of micropropagated Dioscorea bulbifera was observed on Murashige and Skoog medium. The effects of two plant growth regulators; 6-benzylaminopurine, BAP (0.5, 1.0, 2.0 and 3.0) mg/l and α-naphthalene acetic acid, NAA (1.0, 2.0, 3.0 and 4.0) mg/l was used singly and in combination. Culture was maintained at 25 ± 2°C with 16/8-light/ dark photoperiod and a light intensity of 40 lmol m-2 s-1 provided by cool white fluorescent tubes. Results showed that treatment with 2 mg/L of NAA in shoot length 4.01±0.33 was remarkably high and the root length 2.28±0.64 was statistically significant. Also, 2 mg/L of BAP produced the highest shoot length 2.92±1.16 significantly. The combination of 1BAP+2NAA had the highest of proliferation of 3.10±0.46 followed by 2BAP+3NAA that produced 2.41±0.25. In this present study, the synergistic and advantageous effects of BAP and NAA on D. bulbifera culture boosted shoot induction and proliferation.