The suppression of reproduction of Tragopogon pratensis infected by the rust fungus Puccinia hysterium

Analysis of seeds collected from rust (Puccinia hysterium) infected and uninfected Tragopogon pratensis, located within the Park Grass Experiment at Rothamsted Research, has shown a significant difference in the number of seeds produced and also in the subsequent number of successful germinations between seeds set by infected and uninfected plants. This supports the hypothesis that P. hysterium significantly suppresses reproduction in T. pratensis. Furthermore, seeds from infected individuals have significantly shorter pappi and seed mid-lengths whilst having no significant difference in seed mass, indicating that seeds from infected hosts have altered growth form.