Research progress on tissue culture techniques of Anoectochilus roxburghii

Anoectochilus roxburghii is an herbaceous plant which is used as a Chinese herbal medicine and ornamental plant, with high economic and medicinal value. In this paper, the recent studies of tissue culture techniques of A. roxburghii are summarized regarding explant selection, minimal medium usage, induction of callus and bud, multiplication culture, and influencing factors. Seeds, nodal segments, stem apices, stems, and leaves are commonly used as explants for tissue cultures of A. roxburghii. Tissue culturing and regeneration of this species mainly relies on three approaches: Firstly, by using a protocorm-like body, with hormones and genotypes being the main influencing factors; secondly, culturing by differentiation from stem segments into buds, with cytokinin and auxin having synergistic effects; and thirdly, by callus differentiation, using the stem pieces and stem segments, as the explants can differentiate into a large number of adventitious buds; here, 6-BA plays a crucial role. In general, light conditions and natural organic matter are important factors to consider in the tissue culture of A. roxburghii. The aim of this paper is to provide an evidence-based protocol for rapid propagation of A. roxburghii, as well as to lay a foundation for protection, utilization and industrialization of A. roxburghii.