Association of Candidatus phytoplasma in stone fruit trees of Golestan province of Iran: a diagnostic study report

Subject Areas : Plant Pests

Mohammadreza Zarhoon ¹ (Former MSc. Student, Department of Plant Pathology, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran)
Saeed nasrollahnejad ² (Associate Professor, Department of Plant Protection, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran)
Elham Mahmoudi ³ (PhD student in Plant Pathology, Department of Plant Protection, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran)
Atena Zahedi Tabarestani ⁴ (3. PhD student in Plant Pathology, Department of Plant Protection, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran)

Received: 2023-08-15 Accepted : 2023-08-15 Published : 2023-02-20

Keywords: phylogenetic analysis, phytoplasma, Stone fruit trees, peach yellows and decline,

Abstract :

In the visits of the spring, summer, and autumn of 2021 and 2022 to the orchards of stone fruit trees in Golestan province, suspected symptoms of phytoplasma disease such as yellowness, deterioration, reddening, and small leaves were observed, and 28 samples of leaves from different hosts of stone fruit trees were collected. P1/P7 general primers were used for general PCR, and R16F2n/R16R2 primers were used for nested PCR. Infected samples amplified 1800 bp fragments in general PCR and 1250 bp fragment in nested PCR. Out of the 28 samples collected, 3 samples of peach trees had a band in the target area. The nested PCR product after sequencing was registered in the World Gene Bank with accession numbers OQ945143 and OP055811. At the same time, transplanting was done on the benchmark plant, Periwinkle, with the aim of gene storage and observation of phytoplasma symptoms. The comparison of the obtained sequences with the sequences available on the NCBI by the BLAST showed the most similarity to Aster yellows phytoplasmas, and the phylogenetic analysis of the target sequence with the maximum likelihood estimation algorithm in comparison with the different phytoplasma subgroups reported in Iran also showed the results confirmed the blast. Also, the comparison of patterns obtained from virtual RFLP identified the most similar reference pattern of the 16SrI group, subtype AD (GenBank accession: DQ286577), with a similarity coefficient of 0.77, which indicates that this strain may represent a new group. The results of this study confirm the presence of phytoplasma in peach trees in Golestan province for the first time and indicate the presence of a phytoplasma species close to Candidatus phytoplasma asteris in Golestan province.