The protection of ancient tea trees has a scientific basis

The protection of ancient tea trees has a scientific basis

The protection of ancient tea trees has a scientific basis for the protection of ancient tea trees

Ancient tea tree photo by Zhao Degang

 Ancient tea tree photo by Zhao Degang

"The tea of ​​the world looks at China, and the tea of ​​China looks at Yungui
.

" China is one of the first countries to discover and cultivate tea trees, and it is also the origin of tea culture

Recently, Professor Zhao Degang’s team at the Key Laboratory of Mountain Plant Resources Conservation and Germplasm Innovation of the Ministry of Education, Guizhou University, used population genetics research methods to explore the origins of eight ancient tea populations in Yungui region from the genomic level, combined with the characteristics and characteristics of the tea trees of origin.
Evolutionary relationships and identified candidate genes related to important agronomic traits of tea plants
.

Related results were published online in "Horticultural Research"
.

This research provides an important supplement to the research on the phylogeny, population structure and genetic diversity of ancient tea trees in southwestern China, and provides an important reference for the research on the genetic relationship and evolution path of tea trees

Valuable natural gene pool

Valuable natural gene pool

Tea is the most popular non-alcoholic beverage in the world, with attractive aroma and pleasant taste
.

Tea beverages are rich in compounds that are beneficial to the human body, such as polyphenols, caffeine, theanine, vitamins, polysaccharides, volatile oils and minerals

The unique topography and ecological environment of Yunnan-Guizhou region contain a lot of ancient tea tree resources
.

"These ancient tea trees have important ecological, scientific, economic, and social and cultural values.

And this area of ​​Guizhou has its own unique features
.

As a transition zone for tea trees to migrate to the Jiangbei, Jiangnan and South China tea regions, the climatic conditions and ecological environment here have bred rich tea plant resources.

Ancient Arbor Tea Tree Photo courtesy of Lu Litang

Ancient Arbor Tea Tree Photo courtesy of Lu Litang

According to statistics, there are more than 650,000 ancient tea trees in Guizhou province.
There are more than 10 contiguous ancient tea gardens over 1,000 acres, and there are many rare wild and artificially selected local characteristic group varieties with geographical indications
.

"Not only that, Guizhou is also the only place where tea seed fossils are found in the world.
These are enough to reflect the important status of Guizhou ancient tea trees
.

" Lv Litang said in an interview with "China Science News

The precious resources of ancient tea trees need to be inherited and protected.
With the promulgation and implementation of the "Regulations on the Protection of Ancient Tea Trees in Guizhou Province", the protection of ancient tea trees has been strengthened
.

"Scientific research on ancient tea trees is to maximize the value, give full play to the advantages of resources, and provide a strong basis for better protection of ancient tea trees

Unravel the mystery of origin

Unravel the mystery of origin

Regarding the research on the origin of tea trees, there are early sayings that they originated in Southeast Asia, India, China's Tibet and the Yunnan-Guizhou Plateau
.

Researchers have discovered abundant germplasm resources of ancient tea trees in Yunnan-Guizhou area.

"Tea is born in Sizhou, Bozhou, Feizhou, Yizhou.
.
.
it is often obtained, and its taste is very good
.
" The area mentioned in this sentence recorded by "tea sage" Lu Yu in "The Classic of Tea" mainly belongs to Guizhou.
Many scholars use this as evidence that Guizhou is the origin of tea
.

The specific origin of tea plant has been controversial for a long time
.

"It is still unclear where the rich resources of ancient tea trees in Yunnan-Guizhou region originated
.
Therefore, it is very necessary to apply morphological characteristics and modern molecular biology techniques to study the distribution, structure, origin and evolution of ancient tea trees
.
" Zhao Degang pointed out
.

In recent years, relying on the Key Laboratory of Mountain Plant Resources Protection and Germplasm Innovation of the Ministry of Education established by Guizhou University, as well as the Institute of Tea of ​​Guizhou University, the Institute of Tea of ​​Guizhou Academy of Agricultural Sciences, the germplasm resources researchers from Guizhou Xishui and General An, Yanhe, Shiqian, Duyun and Sandu, and Yunnan Dali and Hekai collected 120 ancient tea trees with different morphological characteristics
.

Guizhou arbor-type ancient tea tree
.
  Photo by Zhao Degang

Guizhou arbor-type ancient tea tree
.
  Photo by Zhao Degang Photo by Zhao Degang

They used gene resequencing technology and used the Shuchazao genome as the reference genome to identify 8082370 single nucleotide polymorphism sites (SNPs), of which 1,404,774 SNPs were distributed in non-coding regions and 175,824 SNPs were distributed in coding regions.

.

Phylogenetic tree analysis showed that 120 members of ancient tea trees from 8 populations gathered into 3 groups and totaled 5 single branches.
The single branch structure indicated that there was gene exchange among ancient tea trees
.
Researchers also infer that the ancient tea tree population has relatively weak selection and long generation time during the evolution process, and that the ancient tea tree has a higher genetic diversity than the artificially selected cultivated tea tree
.
The results of population genetic structure analysis showed that 120 ancient tea plants clustered into 7 subgroups, and the lines from the same region formed monophyletic clades and shared a common geographical origin
.

"We found that compared with cultivated tea trees, the ancient tea trees from Xishui County, Guizhou Province are the most primitive ancient tea trees, and are more primitive than the ancient tea trees in Hekai, Yunnan and Lincang
.
Xishui County also has the largest number of ancient tea trees in Guizhou Province.
It can be seen everywhere in the virgin forest in a county in China
.
” Lu Litang said that these findings provide important clues for further exploration of the origin and evolution of tea plants
.

Candidate genes are found, research needs to be in-depth

Candidate genes are found, research needs to be in-depth

Ancient tea trees have rich morphological characteristics
.
According to the tea tree type, ancient tea trees can be divided into shrub type and arbor type; according to the leaf size characteristics, they can be divided into small leaf species, medium leaf species, and large leaf species; and the color of the leaves is also different, including green, white, and yellow.
And purple, etc.
; the jagged edges of the leaves are also different
.
These phenotypic traits have attracted the attention of researchers
.

"We want to find an important'switch' to form these agronomic traits
.
" Zhao Degang said
.

Shrub type ancient tea tree
.
Photo courtesy of Lu Litang

Shrub type ancient tea tree
.
Photo courtesy of Lu Litang

The team detected GWAS signals related to leaf traits through genome association analysis.
Based on KEGG annotation and functional analysis of Arabidopsis orthologous genes, they screened out 4 candidate genes that may be involved in plant type regulation, leaf color and other related traits
.

"The origin and place of origin contain abundant germplasm resources, which are the source of genes for the selection of new varieties, which will help to breed new varieties that are specific, high-quality, high-yield, stress-resistant, and resistant to diseases and insect pests in the future
.
Our research is for the development of molecular design breeding.
The work has laid a theoretical foundation and has important strategic significance for the development of the tea industry
.
" Zhao Degang said
.

However, he believes that the content of plant species in different tea groups is also quite different, so the research group needs to be further expanded
.

Lv Litang said that next, it is necessary to collect and analyze the discovered ancient tea tree populations on a larger scale, to clarify the ancient tea tree population structure, evolutionary status, genetic variation of specific traits, and excellent trait formation and adaptation mechanisms in order to protect and utilize ancient tea germplasm.
Resources provide theoretical basis
.

Related paper information: https://doi.
org/10.
1038/s41438-021-00617-9