Swiss agrochemical company Syngenta AG — in cooperation with Chinese researchers and Science journal — has released draft sequences of the genomes of two of the most commonly grown rice subspecies.
Publication of Syngenta's rice genome map is a breakthrough in agricultural research, said Steven Briggs, head of genomics for Syngenta. “For the first time, the DNA sequence of a crop has been determined and, most importantly, the DNA sequence has been joined with the plant breeders' genetic map of commercial traits.”
The mapping effort was an international affair. Canadian physicist Gane Ka-Shu Wong (who worked with colleagues at the University of Washington) and Beijing's Genomic Institute sequenced the genome of indica, a strain grown in tropical climates. Syngenta sequenced japonica, a cooler-weather strain.
At 420 million nucleotides in length, Syngenta's rice genome map is more than 99 percent complete, said Briggs. It's the largest genome map yet produced to this level of completion and the data is “99.8 percent accurate.”
There are approximately 45,000 genes in rice and the newly released maps will revolutionize plant breeding. “Plant breeding today is like searching for a needle in a haystack. With this map, plant breeding will become a process of design,” said Briggs.
The benefits of the maps extend far beyond rice. All of the cereal grains — including rice, corn and wheat — are closely related to each other. Syngenta has been able to use its rice sequencing to construct virtual maps of corn and wheat.
Syngenta plant breeders are now using the virtual maps to create improved commercial varieties such as corn seed that germinates better in cold, wet soils.
Briggs told reporters that Syngenta has developed an access program that balances humanitarian and commercial benefits. The company will provide the map at no cost to world researchers, and Syngenta doesn't ask for intellectual property rights from researchers who use the map.
“We encourage researchers to publish their studies without review by Syngenta,” said Briggs.
Syngenta has invited both the Genomic Institute of Beijing and the members of the International Rice Genome Sequencing Project to join in a concerted effort to finish the rice genome to an accuracy of 99.99 percent.
“We believe this effort can be completed in 12 to 18 months,” said Briggs.
“One nice thing about having not one but two rice subspecies sequenced is that over the next 12 to 18 months we'll be able to get a combined species map for the first time. This will allow us to better understand differences between rice subspecies,” said Wong.
Rice is an important crop, said Donald Kennedy, editor-in-chief of Science. 800 million people are nutritionally deprived on some level with almost all of them living in poor countries of the developing world.
“Rice is the world's calorie champion. More people depend on and consume rice calories than any other crop. This is an important contribution to the capacity to help world health,” said Kennedy. “I'd guess that over the next 20 years, the rice genome will make more difference to global health than the human genome will. This is an extraordinary landmark.
“We've had 75 years of wonderful research on plant breeding to improve the capacity of plants to feed a growing world population. There exists in the world a huge databank of germ plasm stored in seed banks. The sequences from these two studies now make it possible to select much more efficiently from the libraries of genetic information,” said Kennedy.
What about cost of new varieties to farmers? Kennedy believes that with the sequencing is provided to researchers at no cost, farmers will benefit. “Having this sequence means more people will be able to get into the business of breeding. I think that will increase competition. In this environment, competition is the way to get prices down,” Kennedy told reporters.