Enhancing plant regeneration of Lachenalia viridiflora, a critically endangered ornamental geophyte with high floricultural potential

- The current study presents a method for the regeneration of L. viridiflora through somatic embryogenesis for the first time.
- Picloram and TDZ produced a higher number of somatic embryos compared to PGR-free cultures.
- Phloroglucinol promotes the germination of L. viridiflora somatic embryos.

Lachenalia viridiflora is a critically endangered bulbous plant with high potential on the international floriculture market. In the present study, an efficient protocol for in vitro plantlet regeneration through somatic embryogenesis was developed. Embryogenic callus was established from leaf explants cultured on Murashige and Skoog (MS) basal medium supplemented with various concentrations and combinations of picloram and thidiazuron (TDZ). A high number of somatic embryos (28.5 ± 1.49) at different developmental stages of somatic embryos (SEs: globular embryos, juvenile embryo and cotyledon with bipolar characteristics) was obtained on Murashige and Skoog (1962) medium with 2.5 μM picloram, and 1.0 μM TDZ. Histological and scanning electron microscope (SEM) analyses confirmed the presence of somatic embryos. Mature somatic embryos germinated and developed into plantlets after 6 weeks on full strength MS medium. High plant regeneration frequency (91.1%) was achieved on full-strength MS medium supplemented with 5 μM phloroglucinol (PG). Well-developed healthy plantlets were successfully acclimatized in the greenhouse with a survival rate of 90%. The result of this study is beneficial in the mass propagation of high-quality L. viridiflora plants for the commercial horticultural market and also provides a platform for future genetic transformation studies.

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