Clonal bulblet regeneration and endophytic communities profiling of Lycoris sprengeri, an economically valuable bulbous plant of pharmaceutical and ornamental value

Abstract

Lycoris Herb. is valuable as a natural source of starch, broad-spectrum fungicides, and natural compounds with antimicrobial, anticancer and is an antiviral abilities, and for ornamental and urban landscaping plant. The unlimited massive exploitation of Lycoris bulbs has led to a considerable threat to its wild resources and natural habitats. In this study, an efficient protocol for clonal bulblet regeneration of Lycoris sprengeri via seed explants was developed for resource protection and to satisfy the needs of the pharmaceutical and ornamental industries. Contamination-free probulbs were obtained at a rate of approximately 88.7% by using a combination of treatment with HgCl2 for 10 min and NaClO for 5 min to achieve surface sterilization. The endophytic community profiling of seed explants provided a comprehensive overview of changes in the Lycoris endophytes before and after effective surface sterilization. Additionally, the survival of the majority of endophytes without causing secondary contamination suggests the potential utilization of endophytes for the production of novel natural products in vitro. Well-rooted probulbs obtained from Murashige and Skoog’s (MS) medium containing 3% sucrose and 0.2 mg l-1 α-naphthaleneacetic acid (NAA) were selected as secondary explants for multiplication. Cross-cutting without complete separation was superior to complete separation for bulblet multiplication. Maximum bulblet multiplication was achieved in 4.0 mg l−1 6-benzyladenine (BA) and 1.0 mg l-1 NAA with 3% sucrose via direct shoot organogenesis. We were able to transplant approximately 95% of the rooted regenerated bulblets in a natural field after acclimatization. Genetic stability assessment of the in vitro regenerated bulblets was performed using simple sequence repeat (SSR) markers and flow cytometry analysis, with no observed difference compared to seed-germinated probulbs.