New host plants and distribution areas of ‘Candidatus Phytoplasma omanense’-related strains in Iran

During 2015-2018, total DNAs extracted from symptomatic and symptomless fruit and weed plant species in Yazd and Esfahan provinces, Iran, were subjected to direct and nested PCR using P1/P7, R16mF2/R16mR2 and R16F2n/R16R2 primer pairs. Expected amplicons were obtained only from the symptomatic plants. Real and virtual RFLP, phylogenetic and DNA analyses of partial 16S ribosomal sequences of the detected phytoplasma strains showed the presence of phytoplasmas referable to 16SrXXIX group (Cassia witches’ broom phytoplasma) in Prunus persica, Prunus domestica, Diospyros kaki and Sophora alopecuroides with yellowing, reddening, dwarfing, die-back and decline symptoms. This phytoplasma was often detected in mixed infection with others. The need for a precise survey of phytoplasmas associated to symptomatic fruit trees in Iran and a further investigation of the possible role of ‘Candidatus Phytoplasma omanense’ strains as a threat to Iranian fruit orchards are urgently needed