Rapid In vitro Multiplication of Chirita longgangensis W.T. Wang: An Endemic and Endangered Gesneriaceae Species in China

Abstract

Experiments were conducted to establish an efficient protocol for micropropagation of Chirita longgangensis W.T. Wang. Somatic embryos formed directly at the cut edges of C. longgangensis leaf explants on Murashige and Skoog (MS) medium supplemented with benzylaminopurine (BA) and α-naphthalene acetic acid (NAA). During the somatic embryo induction stage, leaf explants and basal leaf explants were used. Leaves were more appropriate explants than the basal leaf explants. The best medium was modified MS macronutrients and micronutrients supplemented with 0.5 mg·L−1 BA and 0.1 mg·L−1 NAA (the best mean number of somatic embryos per explants was 24.10 ± 1.63). The second stage was root induction and elongation. In vitro regenerated plantlets rooted best on MS medium containing 0.1 mg·L−1 indole-3-acetic acid (IAA) and 30 g·L−1 sucrose. Rooted plantlets, following acclimatization in a greenhouse, were successfully transferred to field conditions, and 95% of the plants survived. Application of this protocol has the ability for mass multiplication, in a limited time, of the endangered species C. longgangensis.