The genome was published in the Jan 13 issue of the journal Nature.

This sequencing of the soy genome is the culmination of more than 15 years of collaborative research. The team used a whole-genome shotgun approach to sequence 85 per cent of the 1.1 billion nucleotide base pairs that spell out the soybean's entire DNA code.

Purdue agronomy professor Scott Jackson said the U.S. departments of Energy and Agriculture study found that the soybean has about 46,000 genes, but many of those — 70pc to 80pc — are duplicates. This duplication may make it difficult to target the genes necessary to improve soybean characteristics such as seed size, oil content or yield.

Despite the difficulties the soybean genome presents, having a sequenced genome does speed up the work scientists are able to do to improve the plant's characteristics. Genome sequencing eliminates the need for meticulous searches for particular genes.

"It really is going to change the way we ask questions about soybeans in research," said Randy Shoemaker, a research geneticist from the US Department of Agriculture's Agricultural Research Service at Iowa State University and the paper's co-author. "What used to take us literally years can take us weeks or months now. This is the entire genetic code in front of you."

Having the genome in hand will allow scientists to compare different varieties of soybean plants and determine which genes are responsible for different characteristics, such as increased oil content or larger plants. One of the next steps in the research is to resequence the 20,000 soybean lines in the US germplasm collection to find genes not common to all soybean cultivars.

The US Department of Energy's Joint Genome Institute, Purdue University, the University of Missouri and the University of Arizona-Tucson also participated in the soybean sequencing project, which was supported by the United Soybean Board, National Science Foundation and USDA's National Institute of Food & Agriculture.