Direct in Vitro Organogenesis From Sprouted Seeds of a Highly Economical and Ecological Valued Tree, Korean Pine
Abstract The de novo organogenesis system for Korean pine of this economically and ecologically coniferous species was success fully established using sprouted seeds as the original explants. After 30 days of incubation, 92.67% of explants produced direct shoots on Gupta and Durzan(DCR) medium containing 2 mg · L −1 kinetin (KT) in combination 0.5 mg · L −1 thidiazuron (TDZ) with a maximum of about 15 shoots per explant respectively. We also confirmed the organogenic regeneration pattern by scanning electron microscopy (SEM) observation. For shoot elongation and growth after 60 days of culture, we obtained the highest mean length of 34.99 mm from DCR basal media supplemented with 6-benzyladenine (6-BA; 0.2 mg · L −1 ), 1-Naphthaleneacetic acid (NAA; 0.1 mg · L −1 ), and activated charcoal (AC; 1 g · L −1 ). The highest rooting percentages of 20.74-21.48% were observed within two months in the 1/2 DCR medium (major elements halved) enriched with 0.05 mg·L −1 NAA and 0.5 or 1 mg · L −1 indole-3-butyric acid (IBA). Rooted plants showed a survival rate of 90.28% in perlite: peat: vermiculite = 1:1:1 after acclimatization. This protocol is a successful and efficient biotechnological approach to the micropropagation of Korean pine, and these data will be helpful to the clonal propagation and conservation of Korean pine.