Guwahati, Dec. 31: In a landmark discovery, a team of scientists from different institutions of the country has decoded the first chromosome-scale genome sequence of India's popular Assam type tea variety Tocklai Vegetative 1 (Camellia assamica or C. sinensis var assamica), marking a major advancement in the understanding of tea genetics.
This tea cultivar was developed way back in 1949 by Tocklai Tea Research Institute of Tea Research Association and is still very popular in Indian tea Industry. The original plant is around 90 years old whose genome has been decoded.
This indigenous study, published in a scientific peer reviewed journal Industrial Crops and Products (Elsevier Publication), provides insights into how Assam type tea was evolved, developed its distinctive traits, and synthesized caffeine, revealing the genetic adaptations that differentiate it from China type tea (C sinensis var. sinensis).
"The study established the fact that Assam type of tea is originated in India and is distinctively different from Chinese tea which has been traditionally opposed by tea researcher for many years. This breakthrough holds significant implications for the global tea industry, potentially aiding tea breeders to develop climate resilient, high-yielding, and high-quality varieties," TRA secretary Joydeep Phukan said.
The multi-institutional collaborative study was funded by National Tea Research Foundation, Tea Board India and led by Dr Tapan Kumar Mondal, Principal Scientist, Indian Council of Agricultural Research-National Institute for Plant Biotechnology (NIPB), New Delhi; TRA - Tocklai Tea Research Institute (TTRI) Jorhat, UPASI Tea Research Foundation, TRI, Valparai and Darjeeling Tea Research and Development Centre, Tea Board, Kurseong, West Bengal.
Unlike previous studies, which focused primarily on the China type of tea, this breakthrough is the first in-depth chromosome-level study on Indian Assam type tea of popular cultivar TV-1, a subspecies integral to the tea industry in India, Sri Lanka and African tea-producing nations.
With Assam type tea prized for its strong flavour and high caffeine content, distinguishing it from the milder-flavoured China type tea, the research provides an unparalleled look at how its genome has adapted and diversified, focusing on domestication traits and caffeine biosynthesis pathways.
By analysing 150 tea genotypes in worldwide including 97 major tea cultivars of India, including UPASI, Assam, Palampur Himachal Pradesh and Darjeeling, the study identified that Assam and China tea diverged approximately 5.5 million years ago, each adapting to its specific growing conditions Assam tea in tropical lowlands and China tea in mountainous regions.
The analysis revealed over 500 genes in Assam tea that have been shaped by domestication, including genes linked to caffeine production, leaf size and branching patterns. These traits help explain Assam tea's robust flavour and its adaptability to warm climates. The team also found unique gene fusion events in Assam tea, adding to the understanding of tea's complex evolutionary mechanisms.
The study reveals Assam tea's unique journey through evolution and how it developed its strong taste and high caffeine. "This new genetic information will be a big help to tea farmers and scientists, who can use it to grow better tea plants that meet global demands," Phukan said.
Recently, the same team also released the first ever organelle (chloroplast and mitochondrial) genomes of this Indian tea cultivar (Tocklai Vegetative 1) and have revealed distinct origin of Indian Assam tea and China type tea from chloroplast genome sequence-based phylogenetic studies.
- By Staff Reporter
