Micropropagation by Axillary Budding of Ornamental Camellia Species: A Case Study of Camellia japonica and Camellia reticulata

ABSTRACT: Biotechnological methods, particularly in vitro and tissue culture techniques, represent valuable tools for the large-scale multiplication, genetic improvement, and conservation of numerous plant species. Among these, axillary shoot proliferation based on culture of meristems is the most commonly applied micropropagation strategy, as it generally ensures high genetic stability in the regenerated plants. Here, we review the implementation of this micropropagation technique in two important ornamental species of the genus Camellia: C. japonica cv ‘Alba Plena’ and C. reticulata cv ‘Captain Rawes’, both of notable horticultural interest due to the aesthetic and commercial value of their flowers. Through this micropropagation technique, vigorous and healthy plantlets were obtained, acclimatized, and subsequently transferred to ex vitro conditions, demonstrating the feasibility of this propagation system for the production, maintenance, and potential enhancement of elite Camellia germplasm. In vitro cultures of both species were successfully maintained under cold storage conditions for at least 18 months, preserving their viability and regenerative capacity. Importantly, the protocols described here were established using adult camellia material, a plant material often considered more challenging for in vitro propagation due to reduced morphogenic competence.