ORNL/BFDP Poplar Drought Tolerance Research

Background

Drought tolerance of various species of poplar trees (Populus) and their hybrid offspring is the subject of a cooperative research and development agreement (CRADA) between Oak Ridge National Laboratory, Bioenergy Feedstock Development Program (BFDP) and Boise Cascade Corporation. The purpose of the CRADA is to verify that certain biochemical indicators can be used to predict which poplar clones can best survive periods of little or no rain and still be productive.

Research has shown that some individual plants and plant species tolerate water shortages by maintaining or accumulating high concentrations of sugars, amino acids, organic acids, and inorganic ions. The presence and elevated amounts of these substances may indicate that a particular plant can tolerate drought.

Methodology

In a study of six poplar clones, the ORNL researchers isolated 60 to 80 metabolites that may be involved in drought tolerance. High concentrations of several metabolites were found in clones identified as drought tolerant.

For the CRADA, which is funded by the U.S. Department of Energy's Office of Transportation Technologies, the ORNL researchers will validate whether these plant metabolites can be used to identify drought tolerance in poplar trees. Boise Cascade is poplar clones under six levels of irrigation in their drought stress facility in eastern Oregon. ORNL will collect leaf samples from these trees, measure the total amount of dissolved substances, and determine the concentrations of metabolites that may indicate drought tolerance.

In other work related to the CRADA, BFDP researchers will screen 60 genotypes — individuals sharing a unique genetic makeup — in large scale field trials to assess the validity of using the metabolites as drought-tolerance indicators. Molecular markers that prove to be correlated with drought tolerance will be mapped on the Populus genome.

Hoped for Results

The ability of Populus clones to tolerate drought is critical to short- rotation silviculture. The identification of drought-tolerant genotypes will enable industry to manage water resources more efficiently. Boise Cascade, a major U.S. producer of Populus fiber, hopes to use the technology to maintain improved growth rates in hybrid Populus while minimizing use of irrigation water. The ability to use biochemical and molecular markers will reduce the amount of time, money and effort needed to identify and test drought-tolerant genotypes.

For more information

Contact Jerry Tuskan or Tim Tschaplinski, Oak Ridge National Laboratory, P.O. Box 2008. Oak Ridge, TN 37831-6422, 865-576-8141 (Jerry), 865-574-4597 (Tim), 865-576-8143 (fax).