Inducing Early Flowering in Eucalyptus Trees
Eucalyptus is an economically important hardwood tree that is widely planted for pulp, energy, and timber in many countries. There are many active breeding program for Eucalyptus that focused on improving specific traits, such as wood or fiber qualities, insect resistance, and cold tolerance. However, as with most trees, it takes several years for Eucalyptus trees to begin flowering. This long generation time means that tree breeding is a slow process. It is possible to induce earlier flowering in eucalyptus with fertilizer and plant hormone treatments. However, these methods give variable rates of success. An alternative method is to use the power of genetics and plant transformation to create reliable early-flowering Eucalyptus plants. The gene Flowering Locus T (FT) is an important regulator of when plants flower. The addition of extra FT to many plant species, including apples, plums, and citrus, causes these trees to flower at a very young age when the plants are quite small. We transformed the FT gene into hybrid Eucalyptus and regenerated tiny plants, which were transplanted to a warm greenhouse. Less than two months later, the first flower bud opened. The trees have been in continuous bloom since February 2013, and are producing copious flowers. The blossoms are lovely and appear to be normal. Currently, we are testing if these flowers will produce viable seeds, an important consideration for breeding purposes. If successful, FT could be transformed into commercial varieties of Eucalyptus to speed breeding, then the gene removed to provide non-GMO, normally flowering trees for plantations.
This research is being conducted as part of the Tree Biosafety and Genomics Research Cooperative.
June 2013 Poster from the IUFRO Tree Biotechnology meeting in Asheville, NC.
Steve Strauss, Professor, Oregon State University, Cell: 541 760 7357