Mapping of genetic codes likely to lead to better varieties of wheat

Mapping of genetic codes of the food crop by Chinese and US scientists will lead to varieties that are more resilient to disease and harsh weather

PUBLISHED : Wednesday, 03 April, 2013, 12:00am
UPDATED : Wednesday, 03 April, 2013, 2:27pm

Farmers across the globe could be able to grow much better varieties of wheat - the world's most important food crop - in as little as three to five years, according to a member of a team of Chinese and US scientists that has mapped out the genetic code of wheat.

Once scientists finish precisely mapping all the wheat genomes, higher-yielding varieties that are more resilient to disease and harsh weather conditions are expected to be developed.

The recent mapping efforts were a big step in that direction, according to Dr Zhang Aimin, a principal investigator of the Chinese Academy of Sciences' Institute of Genetics and Developmental Biology.

The sequencing and drafting of the A genome, one of the three basic genomes of wheat, was published on the website of the scientific journal Nature last week.

The research was jointly conducted by the academy institute, the Shenzhen-based Beijing Genomics Institute, and the University of California, Davis.

Additional research involving the D genome, jointly conducted by the Chinese Academy of Agricultural Sciences and the Beijing institute, was also published on the website.

"With genomes A and D mapped out, the mapping of all [three] wheat genomes is nearer, because we can find out more about the other genome … more easily based on the first two," Zhang said.

The identification of about 38,000 wheat genes is expected to be of great help to studies on genomic breeding and wheat evolution, domestication and genetic improvement.

The breakthrough means that, "in the near future, we can breed more varieties of wheat that are more productive and of higher quality", Zhang said.

"By selecting the desired genes, we can breed varieties according to the products we want, for example higher-quality bread or noodles," he said.

Globally, wheat is the most commonly consumed of the three staple foods - the others are rice and corn.

A total of 647 million tonnes of wheat was harvested globally last year, and the global trade in wheat is larger than that in all other crops combined, according to the United Nations' Food and Agriculture Organisation.

China is the world's biggest producer of wheat, yielding more than 120 million tonnes last year.

Wang Daowen , also a researcher at the academy institute, told the China Science Daily that considerable progress had been made in breeding new wheat varieties in recent years, but limited knowledge of the crop's genomes had hampered further advancement.

"We did this research mainly because we wanted to contribute to the genetic breeding of wheat, and thereby to food security in our country," Wang was quoted as saying.

Progress of research into wheat genomes had been slow due to their complexity and size, Zhang said. The A genome is larger than the D genome.

Scientists have mapped out the genetic codes of other important crops, including rice, corn and sorghum, which have enabled the development of many improved varieties of them, especially rice, according to Zhang.

He expected there would be "a great improvement in world wheat-breeding technology" in three to five years at the earliest, and within six to seven years at the latest.

China has vowed to stay 95 per cent self-sufficient in the production of its three staple foods, rice, wheat and corn, in order to ensure food security. The nation set an annual production goal of at least 540 million tonnes of grain for 2011-2015.

The central government has also mapped out its first long-term plan for the agricultural seed industry, from 2012 to 2020, as a lack of independent biotechnology and a chaotic seed market have challenged its ability to maintain food security.

Large seed-breeding bases are to be set up, and government-owned institutes and colleges, which currently account for most of the seed breeding, would be forced to withdraw from the sector by 2015, the Ministry of Agriculture said in January.

This story was updated at 2:30pm on April 3 to correct Dr Zhang Aimin's title in the 3rd paragraph. Also, in the 16th paragraph, the second sentence should read "The A genome is larger than the D genome."