شناسایی و تعیین ویژگی های مولکولی فیتوپلاسمای همراه زردی و ریز برگی هلو در استان گلستان

During the spring and summer visits of the years 2021 and 2022 to the fruit orchards in Golestan province, symptoms of yellowing, leaf reddening, decline, leaf curling, and stunted leaves were observed in peach trees across the orchards. Samples showing these symptoms were collected from the orchards and transferred to the laboratory for identification of the disease agent. The disease agent was transmitted to the periwinkle indicator plant by grafting, and in the inoculated plant with the graft, symptoms of yellowing and leaf deformation were observed. After extracting DNA from the symptomatic samples using the plant genomics extraction kit from Denazist Asia, the disease agent was tracked using conventional PCR tests with the primer pair P1/P7 and nested PCR with the primer pair R16F2n/R16R2. Approximately 1250 base pair fragments obtained from nested PCR were sequenced using the Sanger sequencing method by Topaz Gene Company. Comparison of the obtained sequences with the sequences available in NCBI using BLAST software identified a 98% similarity with the phytoplasma species. Phylogenetic tree comparison using the Maximum Likelihood method and the Tamura 3-parameter model in Mega-X software, and the examination of virtual restriction fragment length polymorphism (RFLP) of the amplified region using the iphyclassifier system, showed that the phytoplasma associated with peach yellowing in Golestan province is similar to Candidatus Phytoplasma asteris belonging to the Aster Yellows group (16SrI-AD) . This is the first report of peach yellowing, leaf stunting, and tree decline disease and the characterization of the associated phytoplasma in Golestan province .