Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

First report of Tragopogon dubius witches' broom disease associated with a subgroup 16SrI-B phytoplasma in Iran.

Abstract

In a survey conducted for phytoplasma diseases in 2014, T. dubius witches' broom disease was observed in vineyards and green areas of Bajgah and Zarghan localities (Fars province, Iran). The characteristic symptoms of T. dubius witches' broom were flower virescence and phyllody, crown proliferation and witches' broom. Since the symptoms were suggestive of phytoplasma infection, plants were assayed for presence of phytoplasma by PCR amplification. Based on the results of PCR assays and BLAST and phylogenetic analysis of the nucleotide sequences, the causal agent was identified as a 16SrI-B subgroup phytoplasma ('Candidatus Phytoplasma asteris'). This is thought to be the first report of natural occurrence and partial molecular characterisation of a phytoplasma associated with T. dubius witches' broom disease. A 16SrI-B subgroup phytoplasma has previously been reported as causal agent of rapeseed phyllody disease in Zarghan.