Genetic Diversity, Structure, and Cold Hardiness of Invasive Knotweed (Fallopia spp.) in Minnesota

Abstract

Knotweed (Fallopia spp.) is an herbaceous perennial from East Asia that was brought to Europe and North America and, despite control efforts, subsequently spread aggressively on both continents. Knotweed are known to cause structural damage, riverbank destabilization, and outcompete native species thus reducing biodiversity. Two experiments were conducted: a controlled freezing chamber study to quantify the rhizome cold hardiness of the knotweed complex and whole genome sequencing (DArTseq) of 1,249 individuals from North America, Europe, and Asia with a focus on Minnesotan populations used to measure genetic diversity, population structure, species composition, and indirectly measure asexual and sexual dispersal of knotweed. Fallopia japonica and F. sachalinensis were found to be cold hardy to -10°C and F. xbohemica to -9°C. Minnesota knotweed are genetically diverse and spread both sexually and asexually with the hybrid F. xbohemica being the most prevalent taxon in Minnesota.