An international team of scientists led by the University of California,
Davis (UC Davis), and Michigan State University (MSU) has released the
genetic sequence of the cultivated strawberry.

Whereas most species are diploid, strawberry is an octoploid, with eight
copies of the genome from multiple, distinct parental species. The research,
published in Nature Genetics, unveils how strawberry became an octoploid.
Patrick Edger, MSU assistant professor of horticulture and co-author on the
paper said that they identified all four extant relatives of the diploid
species that sequentially hybridized to create the octoploid strawberry.

The four diploid species are native to Europe, Asia, and North America, but
wild octoploids are almost exclusively distributed across the Americas. The
results also suggest a series of intermediate polyploids, tetraploid, and
hexaploid that formed in Asia, before the octoploid event that occurred in
North America, involving the hexaploid and a diploid species endemic to
Canada and the United States. According to Edger, they found that one of the
parental species in the octoploid controls fruit quality and disease
resistance traits, and they have identified genes controlling various target
traits.

[www.ucdavis.edu]