Inbreeding, Genetic Variation, and Invasiveness: The Strange Case of Bromus tectorum

Abstract

Cheatgrass (Bromus tectorum, downy brome) is arguably the most common plant in the western United States, dominating literally millions of acres of degraded rangeland; yet it is a relative newcomer, having arrived on the scene only a little over a century ago. It first entered the West as an unknown but probably small number of seeds in contaminated grain or packing material, a few years before the turn of the twen tieth century. How did it progress so rapidly from these humble beginnings to become a scourge over such a vast area? Is it still in the process of expansion? The story of how this seemingly innocuous plant has taken over huge areas of western rangelands has engaged the attention of some of our best scientific detectives, and the tale is still not completely told. Unraveling the mystery has required tools from many disciplines, and as new tools are developed and applied, the picture continues to become clearer. Our chapter of the story tells how the tools of population genetics have shed light on the causes of the cheatgrass population explosion.

Keywords

cheatgrass, Bromus tectorum, downy brome

Citation

Meyer, Susan E.; Leger, Elizabeth A. 2010. Inbreeding, Genetic Variation, and Invasiveness: The Strange Case of Bromus tectorum. Rangelands. 32(1): 6-11.