Population Genetic Analysis Infers Migration Pathways of Phytophthora ramorum in US Nurseries
Pie charts show the distribution of the two groups of NA1 isolates, as identified by Structure, among sampled states. Arrows indicate confirmed P. ramorum-positive nursery trace forwards. Blue arrows are 2004 trace forwards and red arrows are 2006 trace forwards. There were no confirmed trace forwards in 2005 or 2007.