Lychee genome-this tropical fruit has a colorful story

They are prickly on the outside and sweet on the inside.

Litchi has been cultivated in China since ancient times, and its cultivation records can be traced back to about 2000 years ago

Now, scientists have used genomics to study the history of litchi in more depth

"Litchi is an important tropical agricultural crop, belonging to the Sapindaceae family.

In addition, "We have identified a specific genetic variation, that is, a piece of deleted genetic material, which can be developed as a simple biomarker for screening lychee varieties with different flowering times, making it for future breeding plans.

"Like a puzzle, we are piecing together the history of human use of lychees," said Dr.

The research will be published in the journal Nature Genetics on January 3

A popular fruit, it has been domesticated more than once

To conduct this research, scientists created a high-quality "reference genome" for a popular lychee variety called "Feizixiao" and compared its DNA with the DNA of other wild and farmed species

Studies have shown that the litchi tree (Litchi chinensis) may have been domesticated more than once: wild litchi originated in Yunnan in southwest China, spread east and south to Hainan Island, and then was domesticated in these two places.

In Yunnan, people began to cultivate very early-flowering varieties, while in Hainan, people began to cultivate late-flowering varieties that would bear fruit later in the year

The exact timing of these events is uncertain

When does this lychee tree bloom? A simple genetic test can tell you

This research not only adds a new chapter to the history of litchi; it also provides an in-depth observation of the flowering time, which is an extremely important feature in agriculture

"Early-maturing lychees and late-maturing lychees come from different places and were domesticated independently," said Dr.

By comparing the DNA of many lychee varieties, the research team discovered a genetic variant that can be used to establish a simple detection method for identifying early-flowering and late-flowering lychee plants

This mutation is a deletion—a missing piece of DNA—located near two genes related to flowering, and may help control the activity of one or two of the genes

The Yunnan cultivars that bloom earlier are missing and inherited from both parents

Albert said: "This is very useful for breeders
.
Because lychees are perishable, the flowering time is very important to extend the season when lychees are on the market
.
"

Sequencing the lychee genome is just the beginning

The SCAU team initiated the litchi genome study as part of a larger project that hopes to greatly expand our understanding of the DNA of the important flowering plant in the same family, the Sapindus family
.

"The Sapindaceae is a large family that includes many economically important plants," said Professor Xia
.
"So far, only a few plants, including litchi, longan, rambutan, yellow horn and maple, have completed whole genome sequencing
.
"

Xia added: “We, the SCAU College of Horticulture, are conducting a large-scale cooperation project to sequence more economically important Sapindus species native to China, such as rambutan and Sapindus ) And balloon vine (balloon vine), aiming to conduct extensive and thorough comparative genomics research on Sapindus family genomics
.
The main research directions will be flowering, secondary metabolism leading to flavor and aroma, flower and fruit development, etc.

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"

Magazine

Natural genetics

DOI

10.
1038/s41588-021-00971-3