From Flask to the Field: Breakthrough Research on Micropropagation of Tea Plants

The Tea Industry of the state is currently facing a number of sustainability challenges like increasing cost of production, a decline of yield and quality, rising cost and climate change. Consequently, the research at Tocklai Tea Research Institute of Tea Research Association Jorhat, a 109 years old premier research institute of the tea industry has focused to offer effective solutions to these challenges. Making available climate-resilient and superior cultivars, as well as an innovative technology for adoption by the gardens, are crucial components for ensuring the sustainability of the industry. Interestingly, the conventional tea plant multiplication methods either through germinating seed or vegetative nodal cuttings are not being able to meet the mounting demand from tea gardens for good planting materials. It calls for a rapid low-cost alternative technology.

Tissue culture has the potential to generate a large number of plantlets within a short time from a single cell or tissue or explants (meaning plant parts). The technology is presently applied in case of micro-propagation of orchid, banana etc. But the technology could not be utilized so far for mass propagation of tea plants due to difficulty in rooting and hardening of in-vitro cultured tea plants. Most of the tea tissue culture work was successful in the laboratory only and that too using the germinating seeds as the starting material. There are also reports that the few hardened tea plants do not grow well in the field conditions. It was a big challenge as well to regenerate tea plantlet in in-vitro condition from field-collected tea shoots thanks to severe contaminations.

TRA Tocklai has recently come up with an answer to both these problems that has been plaguing the tea tissue culture work for quite some time. This will also lead to revenue generation for TRA as per the mandate given by Government of India to TRA to become self-sufficient in 5 years time.

In an innovative research, Ms Pranita Hazarika, a young scientist of TRA Tocklai, has cracked these problems and transferred the true tissue cultured tea plants from the flask to the field. The plants have completed 1 year of luxuriant growth and received the first prune on 20th January 2020.

Her work clearly demonstrated that the tissue culture technology can, in fact, be applicable for commercial micro-propagation of tea plantlets at a reasonable price much faster than the conventional methods. It throws up a possibility of a complete transformation of the entire supply chain management of tea planting materials in the near future.

Here we report about the development of a simple and an efficient hardening method of tissue culture raised tea microshoots. The procedure is quite reproducible and require less time by concurrently inducing rooting and hardening of microshoots. In-vitro regeneration of tea plantlet from shoot explants collected from field has also been successfully carried out.