High-frequency in vitro plantlet regeneration in Lilium davidii var. unicolour Salisb, an important edible and medicinal plant, and confirmation of genetic fidelity of regeneration plantlets using ISSR markers

Lilium davidii var. unicolour Salisb is an important edible and medicinal plant. In vitro plantlet regeneration in L. davidii var. unicolour Salisb and identification of genetic stability are the premises of large-scale cultivation, and also a way to meet the increasing global demand. The purpose of this study is to establish an efficient, rapid plant propagation process for L. davidii var. unicolour Salisb, and to define the genetic stability of its regenerants in vitro under optimised conditions. The effects of different concentrations of 6-benzyladenine (6-BA) and thidiazuron (TDZ) on shoot multiplication and growth of L. davidii var. unicolour Salisb were investigated individually, or in combination with α-naphthalene acetic acid (NAA), using Murashige and Skoog (MS) solid or liquid medium. Inter-sample sequence repeat markers were used to assess genetic fidelity among plantlets. The results were that we achieved efficient and reliable regeneration, using scales as explants for shoot induction. The highest mean number (16.8) of shoots was differentiated de novo from the lower portion of the outer scales. After 4 weeks of incubation, superior multiplication rates (9.8%), mean shoot number (3.38), and length (5.46 cm) were achieved using MS liquid medium supplemented with TDZ. Auxins, such as indole butyric acid (IBA) and NAA, were employed for in vitro root induction, and the maximum rooting rate (100%) was observed when samples were cultured on half-strength MS medium supplemented with NAA. In vitro rooted plantlets of L. davidii var. unicolour Salisb were acclimatised in a greenhouse and plants grew well with a 90% survival rate. Inter-sample sequence repeat markers were used to assess genetic fidelity among plantlets, the best ISSR primer UBC 808 had the highest number of reproducible bands and produced 15 distinct bands and all micropropagated plants and the mother plant could be grouped in a single cluster with a 94% similarity level, indicating a low level of genetic polymorphism in micropropagated plants. The developed protocol described herein is simple and reliable for large-scale production of L. davidii var. unicolour Salisb, which provides a good technical support for large-scale cultivation of L. davidii var. unicolour Salisb.