Cover of GENETICS

We are very proud to be on the cover of the journal GENETICS for october with our paper "Dark side of the honeymoon: reconstructing the Asian × European rose breeding history through the lens of genomics...

We are very proud to be on the cover of the journal GENETICS for october with our paper "Dark side of the honeymoon: reconstructing the Asian × European rose breeding history through the lens of genomics". 

Authors

Thibault Leroy, Elise Albert, Tatiana Thouroude, Sylvie Baudino, Jean-Claude Caissard, Annie Chastellier, Jérôme Chameau, Julien Jeauffre, Thérèse Loubert, Saretta Nindya Paramita, Alix Pernet, Vanessa Soufflet-Freslon, Cristiana Oghina-Pavie, Fabrice Foucher, Laurence Hibrand-Saint Oyant, Jérémy Clotault.

Summary

A timeless symbol of love and romance, the rose occupies a special place in the Western imagination. Since Antiquity, it has inspired poets, artists and gardeners. Yet it was only in the XIXᵉ century that the world of roses underwent a true revolution: in just a few decades, the number of varieties rose from around a hundred to over 8,000. An explosion of shapes, colours and fragrances that marked what could be called the golden age of roses.

To understand how this metamorphosis came about, we studied 204 varieties of rose still found in certain botanical collections. We worked on wild species and garden varieties created between 1800 and 1910. We found traces of these creations in catalogues and newspapers from that period and were able to date the creation of each variety precisely. By analysing their visible characteristics (phenotypes) and their DNA, we were able to trace their genetic history in Europe.

The results are astonishing: in just a few generations, the genetic heritage of European roses has been transformed from a predominantly local heritage to an almost entirely Asian profile. This upheaval can be explained by the trade of the XIXᵉ century, when explorers and traders brought back exotic species from the East with such different flowers and fragrances. However, this transformation has come at a price: the genetic diversity of roses has been impoverished, an inevitable consequence of intensive selection. Some highly prized characteristics, such as the ‘tea’ fragrance and the almost continuous flowering until autumn, come directly from the Chinese roses introduced at that time.

Our work has also led to the creation of the most extensive catalogue of genetic associations (GWAS) ever produced for roses, a valuable resource for future breeding programmes. It also underlines an essential message: preserving old varieties is crucial to maintaining the genetic richness of roses and ensuring sustainable breeding for generations to come. For example, it is in these collections that we will have to look for natural resistance to pathogens to do without pesticides, or search for new fragrances.

This article is published in tribute to Laurence Hibrand-Saint Oyant, our colleague in Angers, who died suddenly during the course of this work.