In vitro Rapid Mass Propagation from Leaf Culture of <i>Drosera rotundifolia</i>

Abstract

This study was conducted to establish a rapid mass propagation system by leaf culture of Drosera rotundifolia, a representative insectivorous plant that grows naturally in Korea. We evaluated the effects of explants [leaf blade, leaf blade (cut-square), petiole, leaf blade+petiole, leaf blade+petiole (center-cut)], media strength [1/4 MS (Murashige and Skoog), 1/2 MS, 1MS, and 2 MS], culture methods (liquid and solid media), culture condition (1 week under light after 4 weeks under dark, 3 weeks under light after 2 weeks under dark and 5 weeks under light) and cytokinin (BA, kinetin) on shoot and plant regeneration. In the treatment by solid medium, of shoots were the highest (100%, 1.8 shoots per explant) in 1/4 MS and 1/2 MS with leaf blade (cut-square), and leaf blade+petiole with 100% and 1.6 - 1.8 shoots per explant. In the treatment by liquid medium, plant regeneration rate was shown to be 100% in 1/2 MS with leaf blade (cut-square), and number of shoots was high f rom 2.6 - 2.7 in 1/4 MS and 1/2 MS, respectively, both with leaf blade (cut-square) and leaf blade+petiole (center-cut). Comparing solid to liquid medium, the result of culturing of liquid medium for five weeks is better than that of solid medium for eight weeks, which is deemed to be efficient for plant regeneration in D. rotundifolia. In culture conditions, the highest number of shoots was 3.5 - 3.6, respectively, in 1/4 MS with 1 week under light after 4 weeks under dark and 3 weeks under light after 2 weeks under dark. In conclusion, the growth of D. rotundifolia, 1/4 MS with 3 weeks under light after 2 weeks under dark are considered the best for the in vitro growth of D. rotundifolia. In this experiment, the shoot and root growth were found to be better in MS medium without cytokinin rather than with cytokinin.