Comparative analysis of chloroplast genomes indicated different origin for Indian tea (Camellia assamica cv TV1) as compared to Chinese tea

Hukam C Rawal,Nagendra Kumar Singh,Tapan Kumar Mondal,R Victor J Ilango,Biswajit Bera,S Soundararajan,Sangeeta Borchetia,Anoop Kumar Barooah,Tilak Raj Sharma

doi:10.1038/s41598-020-80431-w

Abstract

Based upon the morphological characteristics, tea is classified botanically into 2 main types i.e. Assam and China, which are morphologically very distinct. Further, they are so easily pollinated among themselves, that a third category, Cambod type is also described. Although the general consensus of origin of tea is India, Burma and China adjoining area, yet specific origin of China and Assam type tea are not yet clear. Thus, we made an attempt to understand the origin of Indian tea through the comparative analysis of different chloroplast (cp) genomes under the Camellia genus by performing evolutionary study and comparing simple sequence repeats (SSRs) and codon usage distribution patterns among them. The Cp genome based phylogenetic analysis indicated that Indian Tea, TV1 formed a different group from that of China tea, indicating that TV1 might have undergone different domestications and hence owe different origins. The simple sequence repeats (SSRs) analysis and codon usage distribution patterns also supported the clustering order in the cp genome based phylogenetic tree.

Highlights

Based upon the morphological characteristics, tea is classified botanically into 2 main types i.e. Assam and China, which are morphologically very distinct
The Maximum likelihood (ML) tree based on alignment of cp genome sequences using GTRGAMMAX model at 1000 bootstrap replicates supported the branching-off of the bryophyte M
V. vinifera and A. thaliana are the species to get separated from rest of the species, all of which belongs to Asterids group

Summary

Introduction

Based upon the morphological characteristics, tea is classified botanically into 2 main types i.e. Assam and China, which are morphologically very distinct. Based upon the morphological characters, they are divided broadly into three types such as China tea, Assam tea and a hybrid between them called Cambod tea. Due to their high out-crossing nature, they breed freely among themselves which produce plant type that is an intermediate between the two extreme forms i.e. Assam type big leaf and China type small leaf. Indo-Burma region near Irrawaddy river is considered to be the centre of origin[5], yet it is not clear whether Assam and China type tea have same or different domestication origin

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Conclusion