MODIFYING POPULUS ENVIRONMENTAL RESPONSES: IMPACTS ON WOOD QUANTITY AND QUALITY

摘要

Natural selection for environmental fitness has led to a wide variety of wood properties between and within trees. In the redesign of trees to better serve industry needs, we believe that a focus on modifying genetic control of environmental responses can simultaneously improve total wood yield, tailor wood properties for different uses, and reduce the within tree variation in wood properties. To do that, we need much more understanding of environmental signals, the physiological processes they elicit, and the resulting changes in wood formation. We are studying two types of environmental interactions that we know have large impacts on wood yield, competition effects and responses to pest attack, to determine the corresponding impacts on wood properties. In wild trees, both of theses environmental factors cause a shift in allocation of photosynthate away from stem wood formation to stem height growth and/or replacement of shaded or damaged leaves. Concurrent changes in hormone levels within the tree may impact wood quality traits such as specific gravity and fiber length. We have started evaluating model systems to look at the magnitude of these effects. We discuss results from a spacing trial and an insect impact study in this paper.