Quality Planting Material Production through Efficient and Low Cost Micro Propagation Protocol in Ginger (Zingiber officinale Rosc.)
The repeated planting of ginger in field becomes source of inoculum of pathogens for various diseases, resulting in reduced production and productivity and sometimes wipes out cultivation in traditional pockets. In vitro multiplication can be effective means for elimination of pathogens from vegetative propagated material. It can also help in round the year production of thousands of ginger plantlets from single shoot. But high cost of tissue cultured multiplied planting material coupled with poor success in successful field transfer is hampering its commercialisation. The major components which lead to increased costs of culture media are expensive agar agar (used as gelling agent) and sucrose (used as carbon source). High cost for initial infrastructure and recurring maintenance charges for temperature and light also hampers progress. This paper describes, a reproducible and cost effective method of multiplication of ginger in vitro using Isubgol (mucilaginous husk derived from the seeds of Plantago ovata) as a gelling agent, ordinary (table) sugar in culture medium and natural light, improved practices for field transfer and further advancement for making possible commercial sized rhizomes.. The protocol involves six stages, but three basic steps. For initiation of aseptic cultures (1st step) MS-medium supplemented with cytokinin (5-10 mg1-) + sucrose (3%) + agar (0.8%) was used. For multiple shoot formation (2nd step), MS-medium supplemented with BAP (2.0 mg1-) + NAA (0.5 mg1-) + table Sugar along with Isubgol (3%) as gelling agent was used. Subsequent multiplication and maintenance of cultures in various cycles is possible on basal MS medium with lower doses of BAP (0.5-1.0 mg1-) or even on hormone-free medium with agar or Isubgol as gelling agent in indirect natural lights in rooms or under shade of tree using properly sealed cultured vessels. The shoot and root formation were simultaneous and there was no need of ex-vitro rooting. Hardening and field transfer (3rd step) that involved adaptation under decreasing humidity and increasing light coupled with bio hardening was also done. The field performance of plantlets derived from Isubgol gelled medium was relatively better. The micro-propagated plantlets grown under green house in poly bags using soil mixture containing Trichoderma as antagonist/growth promoter resulted in production of mini rhizomes that were disease-free. These mini rhizomes were uprooted, stored using improved practices and again planted in field to get commercial sized rhizomes. The performance of crop raised from these rhizomes (2nd generation) initially derived form costeffective medium was relatively better. The performance of the crop raised from these commercial sized rhizomes produced through tissue culture cycle was relatively better when compared with the crop raised from conventional seed rhizomes.