The first full sequence of a rose genome has revealed the source of key traits of today’s roses.
Roses have been intensively bred over centuries to improve characteristics such as scent and colour. As a result, modern rose genomes contain many gene variants, making their sequences hard to assemble.
Mohammed Bendahmane at the École Normale Supérieure in Lyon, France, and his colleagues generated the genome of the ‘Old Blush’ variety of Rosa chinensis, an ancestor of hundreds of modern roses, by forcing its male reproductive cells to reproduce asexually. The genome that this created was less complex than those previously analysed.
The results showed that genes for flower quality, such as recurrent flowering, are located on chromosomal segments transmitted to modern roses from Chinese roses imported to Europe in the eighteenth century. The team also found that related pathways control flower colour and some aspects of scent.
The genome will help breeders to improve rose quality.