Phytoplasmas were positively identified in T. grandiflorum and T. erectum in Ontario in 2016 and later confirmed in 2019. Phylogenetic analysis supported the grouping of the phytoplasmas isolated from infected plants as a related strain of 'Candidatus Phytoplasma pruni' (subgroup 16SrIII-F) with 99% sequence identity. This subgroup of phytoplasmas is associated with various other diseases, including milkweed yellows, Vaccinium witches' broom, and potato purple top.
