Unravelling the secrets of strawberry

Scientists have unravelled the genetic secret of a Christmas favourite – the strawberry.

Scientists from 38 organisations in ten countries, including scientists at Plant & Food Research, have collaborated to publish the complete DNA sequence of woodland strawberry. This genome sequence will be utilised by scientists in identifying genes and gene function in a number of fruit crops, ultimately speeding up the time to produce new varieties.

The woodland strawberry was the original strawberry cultivated in Europe in the 17th Century. It is cousin to a modern Christmas favourite, the garden strawberry, one of the youngest cultivated fruits originating around 250 years ago through modern plant breeding techniques.

The strawberry has the smallest genome in the Rosaceae family, which includes other well known fruits such as apple, peach, and berries. Due to its quick reproduction time and the small area needed to grow the plant, strawberry is an ideal model plant for fruit gene studies. Most of the genes in strawberry are present in other Rosaceae plants, although many are duplicated resulting in more complex genomes and plant structures. Using the strawberry genome to identify and understand genes that control key traits, such as colour and flavour, scientists can identify the matching gene in other fruit plants and screen breeding populations for individual plants with ideal characteristic combinations.

“The Rosaceae family is vital for modern horticulture, producing highly valuable fruits such apple, peach, nectarine, almonds and berryfruits,” says Dr Roger Hellens, Science Leader Genomics at Plant & Food Research. “By having the sequence of the most genetically-basic of these plants, strawberry, we can search for genes controlling key commercial traits and identify them in related plants. This will ultimately speed up our search in the more complex Rosaceae genomes and allow us to reduce the time to breed fruit plants with characteristics most desired by the consumer.”

The complete genome of the woodland strawberry, Fragaria vesca, is published in the prestigious journal Nature Genetics and includes only 206 million DNA base pairs, encoding close to 35,000 genes. The apple genome, published in August 2010, is three times the size. The strawberry genome is the second smallest plant genome to be sequenced – the sequence for Arabidopsis, widely used as a model in plant studies, is about 125 million DNA base pairs and was first published in 2000.