WASHINGTON, Aug. 29, 2010 – An international team of scientists funded by the U.S. Department of Agriculture has published a draft sequence of the domestic apple genome in the current issue of Nature Genetics.
"The United States is the world's second largest producer of apples, with annual production valued at more than $1 billion and the completion of the sequence of the apple genome gives researchers an important tool that can be used to develop nutritious fruit of the highest quality for American consumers," said Roger Beachy, director of USDA's National Institute of Food and Agriculture.
Washington State University (WSU) researcher Amit Dhingra, in collaboration with WSU computer scientist Ananth Kalyanaraman and University of Washington microbiologist Roger Bumgarner, sequenced and analyzed a double haploid version of the genome of the apple variety Golden Delicious. This information was used to validate the assembly of the heterozygous Golden Delicious apple. They also compared gene islands from the apple genome landscape with that of pear, peach and grape to identify genetic differences that make it possible to trace the lineages among these important fruit crops.
An organism's genome is the total of all its genetic information, including genes. Genes carry information that determines, among other things, an organism's appearance and health. Knowing the sequence of the apple genome will ultimately allow scientists to point to a specific gene and identify the trait it is responsible for. Scientists will begin using the apple genome to help breed apples with desirable new traits, including disease resistance, flavor and, potentially, increased health-benefitting qualities.
Although the economic importance of having the apple genome in hand cannot be understated, the pressing question answered by the international team's paper in Nature Genetics was one of origin. Scientists have long wanted to know -- and have for years argued vehemently about -- the ancestor of the modern domesticated apple. The question is now settled: Malus sieversii, native to the mountains of southern Kazakhstan, is the apple's wild ancestor.
The apple genome is available digitally on Dhingra's Genomics Lab website as well as the Tree Fruit Genome Database Resources website, the online Rosaceae family genomic database accessed by scientists millions of times per year.