Scientists conquer the ‘Mount Everest of genetics’ after unlocking secrets of wheat genome
Researchers hope mapping Chinese Spring wheat’s genetic code – one of the most complex known to science – will allow them to develop new strains of the staple crop
An international team of scientists have cracked the genetic code of wheat, a staple food for a third of the world’s population, in a breakthrough that could pave the way for the development of new, higher-yielding varieties.
Researchers said the successful conclusion of the 13-year project to map the genome of Chinese Spring wheat would also help develop new strains that have a higher nutritional value and are better adapted to cope with climate change.
The study was conducted by the International Wheat Genome Sequencing Consortium, a collaboration among more than 2,000 scientists from over 20 countries, including Australia and China. The results were published in the journal Science on Thursday.
“Sequencing the wheat genome is like climbing Mount Everest,” said Rudi Appels, a genetics professor at the University of Melbourne and one of the six co-chairs of the consortium. “People thought we were mad.”
Appels said that deciphering the wheat genome had long been seen as mission impossible because the crop has one of the most complex genomes known to science.
The genome contains about 16 billion base pairs of DNA, compared with around 3.3 billion in human DNA.
“It’s a milestone for agriculture as the genome sequencing will speed up the process by which we cultivate wheat varieties with higher yields and nutritional value,” said Tian Aimei, a plant breeder at Xian University of Arts and Science in northwest China. “Everyone in the field is closely following the sequencing project.”
Appels said the completed project had given wheat growers the equivalent of Google Maps when trying to locate the specific functions of the species’s genes.
“Instead of trying every address, you can walk directly to the location and find the gene you are looking for,” he added.
The project focused on Chinese Spring, which was widely cultivated across China before the 1950s. The strain was found in Sichuan province by a missionary, who later helped bring it to the US, South America and Britain in the early years of the 20th century.
“No other variety has played such an important role in genetics,” said Song Weining, a biology professor with Northwest Agriculture and Forest University who has been involved in the project since its inception in 2005.
“It became a standard for wheat researchers as the variety shows a high level of crossability with others such as rye.”
Song also echoed the comparison of the breakthrough to a map, saying it will “make breeding much more efficient as they now have a guidebook in their hands”.
Song’s work was partially funded by China’s Ministry of Science and Education, he said, because wheat was seen a strategic crop.
China is the by far the world’s largest wheat producer, with the country’s breadbasket being located in the Yellow and Huai river valleys.
China harvested about 128.9 million tonnes of wheat in the agricultural year of 2016/17, accounting for 17 per cent of the world’s total wheat production in that period, according to recent figures from the UN’s Food and Agriculture Organisation and the US Department of Agriculture.
Farmers in China stopped using the Chinese Spring variety in the 1950s when modern breeding techniques led to the development of new strains with higher yields and better resistance, Song said.
“But the variety is still key to understanding how wheat evolves and what genes control the most sought-after traits, such as resistance to drought and pests,” he said.
Luo Mingcheng, a genetics professor with the University of California, Davis and a member of the project, said the sequencing work will spur more research to identify which genes control these key traits.