The causal phytoplasma of gentian witches'-broom, found in Iwate Prefecture in 2005, was identified phylogenetically as ‘Candidatus Phytoplasma asteris’, but not ‘Candidatus Phytoplasma pruni’, which was previously reported as the pathogen of gentian witches' broom in Japan. The causal phytoplasma was also revealed to be transmitted by Macrosteles striifrons. We propose adding ‘Candidatus Phytoplsma asteris’ to the pathogens of gentian witches'-broom.
