High-frequency in vitro multiplication of disease-free Zingiber officinale Rosc

High-frequency in vitro multiplication of disease-free clones of ginger (Zingiber officinale Rosc.) was obtained by culturing small and active buds of ginger on MS medium supplemented with 2 mg/l Kin and 20 g/l sucrose. An average of 7.7 shoots per bud was obtained on this medium after 4 weeks of culture. A high multiplication rate of well-developed plantlets (7.0 shoots per bud) with a 6.8-cm shoot length and a 7.0-cm root length was also obtained on MS medium containing 2.0 mg Kin, 2.0 mg NAA and 20 g sucrose per liter. The multiplication rate did not decrease even up to 28 months of subculture on the same medium. A simple method of successfully transferring more than 95% of tissue-cultured plants into pots was also standardized. In vitro-derived plants performed well under field conditions, were morphologically identical to the mother plants and were free from ginger yellows (Fusarium oxysporum f. sp. zingiberi). Well-developed rhizomes obtained from the tissue-cultured plants did not rot during storage of up to 6 months, thus indicating that the method is also effective in checking storage rot caused by F. oxysporum f. sp. zingiberi.