Indications for Three Independent Domestication Events for the Tea Plant (Camellia sinensis (L.) O. Kuntze) and New Insights into the Origin of Tea Germplasm in China and India Revealed by Nuclear Microsatellites

PLoS One. 2016 May 24;11(5):e0155369. doi: 10.1371/journal.pone.0155369. eCollection 2016.

Abstract

Background: Tea is the world's most popular non-alcoholic beverage. China and India are known to be the largest tea producing countries and recognized as the centers for the domestication of the tea plant (Camellia sinensis (L.) O. Kuntze). However, molecular studies on the origin, domestication and relationships of the main teas, China type, Assam type and Cambod type are lacking.

Methodology/principal findings: Twenty-three nuclear microsatellite markers were used to investigate the genetic diversity, relatedness, and domestication history of cultivated tea in both China and India. Based on a total of 392 samples, high levels of genetic diversity were observed for all tea types in both countries. The cultivars clustered into three distinct genetic groups (i.e. China tea, Chinese Assam tea and Indian Assam tea) based on STRUCTURE, PCoA and UPGMA analyses with significant pairwise genetic differentiation, corresponding well with their geographical distribution. A high proportion (30%) of the studied tea samples were shown to possess genetic admixtures of different tea types suggesting a hybrid origin for these samples, including the Cambod type.

Conclusions: We demonstrate that Chinese Assam tea is a distinct genetic lineage from Indian Assam tea, and that China tea sampled from India was likely introduced from China directly. Our results further indicate that China type tea, Chinese Assam type tea and Indian Assam type tea are likely the result of three independent domestication events from three separate regions across China and India. Our findings have important implications for the conservation of genetic stocks, as well as future breeding programs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Camellia sinensis / classification*
  • Camellia sinensis / genetics
  • China
  • Domestication
  • Genetic Variation
  • Genotyping Techniques / methods*
  • India
  • Microsatellite Repeats*
  • Phylogeny
  • Phylogeography
  • Seeds / genetics

Associated data

  • Dryad/10.5061/dryad.6gq1g

Grants and funding

This work was funded by the National Natural Science Foundation of China (grant number: 31161140350 to LMG, grant number: 31160175 to BYL, http://www.nsfc.gov.cn), the Ministry of Science and Technology of the People's Republic of China (grant number: 2012FY110800 to LMG, http://www.most.gov.cn), and the Applied Fundamental Research Foundation of Yunnan Province (grant number: 2014GA003 to DZL, http://www.ynstc.gov.cn). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.