in vitro Bulb-Scale Propagation of Lilium leichtlinii var. maximowiczii for Urban Landscaping

Abstract

This study was conducted to establish an efficient in vitro mass-propagation system for the Korean native bulbous plant Lilium leichtlinii var. maximowiczii and to lay the foundation for supplying the produced bulbs for use in flowerbeds. Although this species is a promising native bulbous lily for urban flowerbeds, its use has been limited by the lack of an efficient system for large-scale propagation. L. leichtlinii var. maximowiczii is distributed in the northern part of Gyeonggi-do, Gangwon-do, and the eastern region of Gyeongsangbuk-do in South Korea, and is a native lily species with very high ornamental value. Among the tested disinfection protocols, a 0.1% (w/v) benomyl solution pretreatment for 1 h, followed by 70% (v/v) ethanol (EtOH) for 30 s and sequential surface sterilization in 1% (v/v) sodium hypochlorite (NaOCl) for 20 min and 2% (v/v) NaOCl for 10 min, was the most effective for in vitro introduction of bulb scales. As a result of bulblet induction using combinations of plant growth regulators, the medium containing 2.2 µM BAP + 5.7 µM IAA produced the highest number of bulblets (2.5 ± 0.12 per survived explant; total 38), followed by 4.4 µM BAP + 2.7 µM NAA (2.0 ± 0.00 per survived explant; total 24). Following a total culture period consisting of introduction (3 weeks), formation (3 weeks), and expansion (7 weeks), the regenerated plantlets were acclimatized for 1 week without mortality. These results revealed distinct roles for different plant growth regulators (PGRs) combinations in the regeneration process. The medium supplemented with BAP + IAA was optimal for initial bulblet induction, yielding the highest proliferation efficiency. The in vitro propagation technique established in this study is expected to provide a practical technical basis for the nursery production of uniform L. leichtlinii var. maximowiczii plantlets and to promote their wider use as native flowerbed plants.

Keywords

Bulblet induction / Direct organogenesis / Plant growth regulators / Acclimatization

Statement of the Use of Generative AI and AI-Assisted Technologies in the Writing Process

During the preparation of this work, the authors used Grammarly and Perplexity (AI-assisted tools) to improve readability and language. After using these tools, the authors reviewed and edited the content as needed and took full responsibility for the publication's content.

Acknowledgments

The authors thank Wan‑Hee Lee, Head of the Plant Management & Research Division, and Su‑Mi Park, Director of Seoul Botanic Park, for administrative support and facilitation of this project. The authors also thank the staff of Seoul Botanic Park for their assistance with field sampling, cultivation and in vitro propagation of Lilium accessions.

Author Contributions

I.‑J.C.: Conceptualization, data curation, formal analysis, supervision, writing—original draft, writing—review & editing. H.‑M.P.: data curation, monitoring, ex situ conservation of Lilium, and management of the Lilium culture green house at Seoul Botanic Park. M.‑J.P.: investigation, tissue culture experiments, investigation and ongoing bulb‑scale culture and maintenance of Lilium accessions.

Ethics Statement

Not applicable. This study did not involve humans or animals. The plant materials used in this study are not listed in the IUCN Red List, and no endangered or protected species were harmed during sample collection. All plant sampling and subsequent experiments were conducted in accordance with the guidelines and regulations of Seoul Botanic Park.

Informed Consent Statement

Not applicable.

Data Availability Statement

All data supporting the findings of this study are included in this article.

Funding

This research was funded by the Seoul Metropolitan Government.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper.

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