A green future for poinsettia

Every year, millions of poinsettias brighten up windowsills around the world. But behind the festive plant lies a hidden problem: the beautiful branching, which gives the poinsettia its decorative shape, is caused by a bacterial infection. Without the bacterium, the plant simply cannot be sold, which means that production has for decades relied on controlling this plant disease.

This has created challenges for growers, both in managing the infection and in carrying out the labor-intensive manual pinching of poinsettia shoots necessary to achieve the desired shape.

Now, researchers from Aarhus University, in collaboration with Graff Breeding A/S, have found a completely new path: poinsettias that branch naturally without bacteria and without the need for extensive manual pruning.

A green breakthrough for poinsettias

In the project StarQuality, supported by Innovation Fund Denmark, researchers have investigated the genes that control branching in poinsettias. Using the latest plant breeding techniques, they succeeded in developing plants where a single genetic modification allows the poinsettia to branch naturally.

“We have identified a gene that plays a key role in the plant’s ability to form branches. By modifying this specific gene, we created poinsettias that grow bushy all by themselves without bacterial infection,” explains Christina Rønn Ingvardsen, researcher at the Department of Agroecology.

The result is the first poinsettia with this genetic change, holding great potential for both the industry and the environment.

From laboratory to greenhouse

The development has already led to a patent application and a licensing agreement between Aarhus University and Graff Breeding A/S. This means the technology can now be further developed and eventually brought into commercial production.

For growers, this could mean a significant reduction in labour for pinching, while consumers can look forward to more sustainably grown poinsettias completely free from hidden bacteria.

Perspectives beyond poinsettias

Although StarQuality used poinsettia as its model plant, the results have much broader relevance. The methods and knowledge gained can also be applied to other ornamentals and perhaps even food crops.

“We have shown that it is possible to target breeding in a way that gives plants traits that are attractive to both producers and consumers. This opens new perspectives for developing greener and more robust plants in the future,” says Henrik Brinch-Pedersen, professor at the Department of Agroecology.

Facts: StarQuality

• Title: StarQuality: Platform for Innovative New Green Gearing for Danish Plant Breeding Industry
• Funded by: Innovation Fund Denmark – Grand Solutions 2020
• Partners: Graff Breeding A/S and Aarhus University, Department of Agroecology
• Plant focus: Poinsettia (Euphorbia pulcherrima)
• Results: Identification of a gene controlling branching, development of naturally bushy poinsettias, patent application, and licensing agreement established

Contacts:
Christina Rønn Ingvardsen, Department of Agroecology, Aarhus University
📞 +45 8715 4982 | ✉️ christina.ingvardsen@agro.au.dk

Henrik Brinch-Pedersen, Department of Agroecology, Aarhus University
📞 +45 5123 9017 | ✉️ hbp@agro.au.dk