|In 2008, scientists from the USDA National Forest Genetics Laboratory and Utah State University used a DNA fingerprinting technique to confirm that the Pando clone, originally identified based on morphological traits2, was indeed a single genetic entity1. In other words, this enormous clone at some point in history emerged from a single seed about the size of a flea.|
The Pando clone exists within a larger aspen stand. Although Pando completely dominates this stand spatially, there are other clones within the stand2. In the process of genotyping the Pando clone, USDA and USU scientists discovered that 52 additional clones were identified, most of which were very small (<165 ft/50 m across)5. This very high level of clonal richness was unexpected. Most of these clones were clustered at the edges of the Pando clone, suggesting that they may have arisen from a relatively recent seeding event. This finding, along with a similar pattern found in several other aspen plots in the western U.S.5, was surprising to western forest managers, who previously did not consider seed reproduction to be a significant factor in western aspen regeneration3.
Based on recent genetic work, Pando and many other clones in the western U.S. are triploid, meaning that they have three copies of their genome instead of the usual two copies (diploid)4. Interestingly, the larger clones have a strong tendency to be triploid5, suggesting that triploids have some advantage over diploids. However, triploids may also have particular physiological vulnerabilities (e.g. water stress). Understanding physiological differences between diploid and triploid aspen is a focus of current research at the University of Wisconsin (Lindroth) and Utah State University (Mock).1DeWoody J, Rowe CA, Hipkins VD, Mock KE (2008) “Pando” lives: molecular genetic evidence of a giant aspen clone in central Utah. Western North American Naturalist, 68, 493-497.
For additional information about this research please contact Dr. Karen Mock, Department of Wildland Resources, Utah State University firstname.lastname@example.org