American Elm tree canopy.

MN Impact: Researchers Uncover How Some Elm Cultivars Are More Resistant to DED

January 18, 2019


Researchers will uncover key chemical and morphological characteristics of trees responsible for their increased resistance to diseases (reported as the number of characteristics discovered).


Dutch elm disease (DED) remains the most devastating invasive tree disease to affect Minnesota. Despite extensive research on DED, it remains unclear what mechanisms allow certain elms to be resistant while others are susceptible.

What has been done

Five cultivars and two populations of American elm (3 and 4 years old) were examined for differences in their abilities to compartmentalize and resist infection. The trees were assessed multiple times for disease severity on a 1-12 scale, based on the percentage of permanent wilt in their crown and microscopic analyses of the host-parasite interaction.