One challenge faced by growers of poplar is the flow of pollen into and out of plantations. Poplar trees are wind pollinated, and pollen can travel extremely long distances. Thus, the chance of cross pollination between stands of improved varieties of poplar and wild populations is a distinct possibility.
The goal of our research is to engineer sterile trees for the purpose of genetic containment. We are using both classic and innovative genetic methods to target genes that are important for producing sterile flowers.
Cross pollination is a problem for exotic hybrids, but is a serious regulatory and market problem for genetically engineered trees. We are working to effectively keep pollen from genetically engineered trees out of field research, commercial bioenergy farms and wild poplars.
We have approximately 3,500 trees planted in a 9-acre field trial testing male and female poplar sterility with a widely used technique called RNA interference. The trees are growing well, and had a first year survival rate of 99.1%. We anticipate that one of the female clones will begin flowering in spring of 2014.