Effects of cytokinin–auxin combinations on in vitro propagation of Nepenthes mirabilis (Lour.) Druce

Abstract

The pitcher plants are rare species of the Nepenthes genus, known for their numerous bioactivities and widespread use in folk medicine. Due to overexploitation, the number of Nepenthes mirabilis in the wild is rapidly declining, while efficient in vitro propagation protocols for this species is limited. This investigation was conducted to evaluate the effects of different concentrations of 6-benzyladenine (BA) and indole-3-butyric acid (IBA) combined with 1-naphthaleneacetic acid (NAA) on the growth and development of N. mirabilis (Lour.) Druce under in vitro conditions. The results showed that N. mirabilis shoots cultured on B5 media supplemented with 2 mg.L^-1 BA and 0.5 mg.L^-1 NAA exhibited the highest shoot multiplication, with 15.67 ± 2.50 new leaves and 10.17 ± 1.90 new shoots/explant after 12 weeks of culture. For rooting, B5 media containing 1-3 mg.L^-1 IBA and 0.5 mg.L^-1 NAA significantly increased root number, with the highest value of 14.83 ± 1.94 roots/explant after 12 weeks of culture. This indicated that appropriate concentrations of plant growth regulators should be applied for micropropagation of N. mirabilis in support of conservation and large-scale cultivation.