Severe symptoms of virescence in gladiolus flowers were observed in the Chaharmahal-Bakhtiari province of Iran in 2023. In the areas surveyed the disease incidence ranged from 5% to 40% and has a substantial economic impact, posing a serious threat to gladiolus cut flower production. Given that these disease symptoms have been reported to be associated with the presence of phytoplasmas, verifying the presence and identity of these bacteria is essential for focused disease management. Sequence analyses of the 16S rRNA, ribosomal protein (rp), and tuf genes confirmed the presence of `Candidatus Phytoplasma asteris' and `Ca. P. tritici' strains in the symptomatic plants. Restriction fragment length polymorphism indicated that the phytoplasmas in the 30 symptomatic gladiolus plant samples examined belong to subgroups 16SrI-F and 16SrI-R. These results were also confirmed through phylogenetic analysis on the three studied genes in which the two strains resulted closely related to phytoplasmas in the 16SrI-R and 16SrI-F subgroups, respectively. This is the first report of 16SrI-R and 16SrI-F phytoplasmas associated with the virescence disease in gladiolus plants.
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