Unlocking the Genetic Mysteries of Modern Roses

Roses are one of the world's most beloved and widely cultivated ornamental plants, captivating hearts and adorning gardens for centuries. Despite their popularity, the genetic origins and breeding history of modern roses have remained mostly unknown. A new study has revealed fascinating insights into how the modern rose developed from its ancestors, providing valuable information for cultivating more resilient and breathtaking varieties.

For millennia, roses were cultivated separately in China and Europe, with each region nurturing unique variations. The 18th century marked a turning point when Chinese roses were introduced to Europe, setting the stage for a breakthrough in rose breeding.

Traditionally, the 'Old Blush' China rose has been credited as a major player in this transformation. However, the recent study highlights the significant and previously underappreciated role of another species: Rosa odorata. The fusion of these Eastern and Western roses led to the modern roses we adore today, known for their repeated flowering and diverse forms.

The research project began by decoding the complex genetic makeup of 'Samantha®,' a modern rose variety renowned for its stunning red flowers and continuous blooming.

“'Samantha®' is a tetraploid, meaning it has four sets of chromosomes instead of the usual two, making its genetic structure more intricate and challenging to study,” said Zhangjun Fei, a professor at the Boyce Thompson Institute and one of the study’s lead authors. “By mapping its genome, we created a powerful resource for future comparative and evolutionary genomic studies and for advancing rose breeding efforts.”

The research team also sequenced the DNA of 233 other rose varieties, from wild types to modern cultivars. This allowed them to create a "genome variation map," a reference for understanding how modern roses evolved from their ancestors.

With this resource, breeders can develop roses that are not only more beautiful but also hardier and better suited to various climates. Imagine roses that bloom longer, require less care, and are more resistant to pests and diseases.

The study, recently published in Nature Plants, found that human selection has significantly influenced the genetic diversity of modern roses. Over the years, traits such as continuous and recurrent flowering, double flowers, and disease resistance have been carefully cultivated.

However, the researchers emphasize that preserving a wide range of genetic traits is essential for the health and adaptability of these stunning flowers. In an era of climate change and environmental challenges, genetic diversity is crucial for ensuring that roses can continue to thrive in changing conditions.

This research opens new avenues for understanding and improving one of the world's most cherished flowers. The story of the rose is a rich tapestry woven from threads of history, science, and human passion. Thanks to this study, that tapestry is more vivid and detailed than ever before.