Regeneration of Dracaena surculosa Through Indirect Shoot Organogenesis

This study established a method of regenerating Dracaena surculosa Lindl. 'Florida Beauty' through indirect shoot organogenesis. Bud, leaf, and stem explants were cultured on a Murashige and Skoog basal medium supplemented with N-6-(2-isopentyl) adenine (2iP) at 12.3 and 24.6 mu M with 3-indoleacetic acid (IAA) at 0, 1.1, and 2.3 mu M, respectively, and 2iP at 36.9, 49.2, 61.5, and 73.8 mu M with IAA at 1.1 and 2.3 mu M, respectively. Calluses were induced from leaf explants but failed to produce adventitious shoots. Calluses were also induced from stem and bud explants cultured on the basal medium containing 12.3 mu M 2iP and 2.3 mu M IAA, 24.6 mu M 2iP or higher with either 1.1 or 2.3 mu M IAA. The highest callus induction frequency was 63.2% from stem explants and 69.6% from bud explants when they were cultured on the basal medium supplemented with 49.2 mu M 2iP and 2.3 mu M IAA. The highest shoot formation frequency was 65.7% from stem-derived callus cultured on the basal medium containing 61.5 mu M 2iP and 1.1 mu M IAA and 88% from bud-derived callus cultured with 49.2 mu M 2iP and 1.1 mu M IAA. The highest number of shoots per piece of stem- and bud-derived calluses was 3.8 and 6.7, respectively. Adventitious shoots developed better root systems in the basal medium supplemented with 2.0 mu M IAA. Plantlets after transplantation into a soilless substrate grew vigorously in a shaded greenhouse under a maximum photosynthetic photon flux density of 300 mu mol.m(-2).s(-1). Neither disease incidence nor somaclonal variants were observed in the regenerated population. This established method could be used for efficient micropropagation of D. surculosa, and the availability of tissue-cultured liners could reduce the dependency on imported cuttings, which often bring new or invasive pests into the United States.