Propagation of Ornamental Plants
19(2): 52-58, 2019
MICROPROPAGATION AND SOMACLONAL VARIATION IN HAWORTHIA TRUNCATA SCHÖNLAND
Doo Hwan Kim1, Kyung Won Kang2, and Iyyakkannu Sivanesan1*
1 Department of Bioresources and Food Science, Institute of Natural Science and Agriculture, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, 05029 Seoul, Republic of Korea, *Fax: + 8224503310 *E-mail: email@example.com
2 Babo Orchid Farm, Namyangju-si, Gyeonggi-do 472-831, Republic of Korea
An efficient in vitro propagation system for Haworthia truncata Schönland was developed. Leaf segments obtained from seedlings established in vitro were inoculated on Murashige and Skoog (MS) medium containing 0.5 ml of potassium silicate (K2SiO3), sucrose (30 g l-1), gerlite (4.1 g l-1), various levels of N6-benzyladenine (BA), kinetin (KN), or thidiazuron (TDZ) and different combinations of KN and indole-3-butyric acid (IBA) for adventitious shoot initiation. Of the three cytokinins researched, adventitious shoot production was more responsive to KN than BA and TDZ. Of the various combinations of KN + IBA studied, the greatest rate of adventitious shoot formation (100%) and the highest number of shoots (24.4) were observed on MS medium supplemented with 2.5 µM KN and 0.5 µM IBA. Orange/green, yellow/green, variegated, and pale-green mosaic shoots were obtained on growth medium with KN and IBA. The highest rate of somaclonal variation (61.8%) was found with an average of 5.3 variant shoots on MS medium supplemented with 3.5 µM KN and 1.0 µM IBA. Adventitious shoot buds were subcultured into culture bottles with MS medium containing 0.5 ml of K2SiO3, 0.1% activated charcoal, sucrose (40 g l-1), gerlite (4.1 g l-1), and 0.5 µM KN for shoot growth. The highest rate of rooting (100%) and highest number of roots (12.9) were attained on MS medium supplemented with 2.5 µM IBA. Well-rooted plantlets (normal and variant) were transplanted into plastic cups containing a blend of river sand, peat, orchid stone, and perlite (2 : 1 : 1 : 1) resulting in 81% survival after three months of cultivation in a greenhouse.
Key words: cytokinin, in vitro propagation, morphological change, regeneration, somaclonal variation