Ecological genetics of the <i>Bromus tectorum</i> (Poaceae)–<i>Ustilago bullata</i> (Ustilaginaceae) pathosystem: A role for frequency‐dependent selection?

Abstract

Frequency-dependent selection may operate at endemic disease levels in this pathosystem, but is difficult to detect because many susceptible plants escape infection. Most pathogen isolates were virulent on most host genotypes, minimizing the apparent importance of frequency-dependent selection even during epidemics.