In vitro propagation of Camellia fascicularis: a plant species with extremely small populations

Abstract

Camellia fascicularis is an endangered evergreen ornamental plant with pale yellow flowers. An efficient and reproducible in vitro regeneration method is required for its large-scale propagation and germplasm conservation. In this study, one axillary bud per nodal stem was obtained from C. fascicularis cultured on Murashige & Skoog (MS) medium containing 0.1 mg L−1 indole-3-acetic acid (IAA) combined with 1.0 mg L−1 6-benzylaminopurine (BA). Axillary buds from the stem segments were transferred to modified woody plant medium (WPM) supplemented with 3.0 mg L−1 BA in combination with 0.3 mg L−1 IAA for multiplication, thereby resulting in a high shoot multiplication rate of 6.8. Multiple shoots were divided into nodal stems and shoot tips and were induced to root. The shoot tips were induced to root by culturing on one-half MS medium supplemented with 2.0 mg L−1 indole-3-butyric acid (IBA) in combination with 0.3 mg L−1 α-naphthalene acetic acid (NAA), which resulted in 76.0% rooting efficiency with 2.3 roots per shoot. The optimal hormone ratio for inducing rooting of nodal stems was 1.0 mg L−1 IBA in combination with 2.0 mg L−1 NAA, which resulted in 72.7% rooting efficiency with 1.7 roots per nodal stem. These two rooted plantlets were successfully acclimatized and established in a greenhouse.