Figure: Eucalyptus buds. Photo Source: Oregon State University.

An international research team led by Oregon State University reported that Eucalyptus, a pest-resistant evergreen valued for its hardy lumber and wellness-promoting oil, can be genetically modified not to reproduce sexually, a key step toward preventing the tree from invading native ecosystems.

Led by Steve Krauss from Oregon State University, the team used CRISPR-Cas9 gene editing technique to knock out LEAFY, the master gene behind flower formation. Strauss, Ph.D. student Estefania Elorriaga and research assistant Cathleen Ma teamed up with scientists at the University of Colorado, Beijing Forestry University, and the University of Pretoria on the research. The greenhouse study involved a hybrid of two species, Eucalyptus grandis and E. urophylla that is widely planted in the Southern Hemisphere.

According to Elorriaga, 7% of the world's forests are plantations, and 25% of that area contains non-native species and hybrids. "Eucalyptus is one of the most widely planted genera of forest trees, particularly the 5.7 million hectares of eucalyptus in Brazil, the 4.5 million hectares in China, and 3.9 million hectares in India." Elorriaga notes that those plantings can lead to undesirable mingling with native ecosystems. She added that eliminating those trees' ability to sexually reproduce would be an effective way to greatly reduce the potential for invasive spreading in areas where that is considered an important ecological or economic problem.

For more details, read the article in Oregon State University Newsroom.