ردیابی فیتوپلاسماهای گروه های زردی مینا (16SrI) و افژولش شبدر (16SrVI) در درختچه های شمشاد طلایی در استان خراسان رضوی

The Japanese spindle (Euonymus japonicus) is an evergreen species from the Celastraceae family that is used as a hedge in urban green spaces. Symptoms of stem fasciation and leaf yellowing were observed in some Japanese spindle shrubs in urban green areas in the city of Mashhad in the summer of 2023. Total DNA was extracted from these samples and the nested-PCR method with primer pairs P1/P7 (first round) and R16F2n/R16R2 or R16F1/R16R0 (nested round) was used to identify phytoplasma infection. A fragment of approximately 1250 base pairs was amplified from the samples. The PCR product was extracted from the agarose gel using the Epoch Life Science Kit and sequenced. After analysis with Geneious Prime® 2019.1.3 software, the sequences were submitted to Genbank with accession numbers PP814982 and PP815003. Sequence analysis of the amplified fragments from two different Japanese spindle samples showed that the phytoplasma associated with the symptoms of yellowing and stem fasciation of the shrub is 99% similar to the Aster yellows phytoplasma from the Phytoplasma 16SrI group, and the phytoplasma associated with the symptoms of stem fasciation of the Japanese spindle is 100% similar to the Clover proliferation group from the Phytoplasma 16SrVI group. A virtual RFLP analysis of the amplified fragment was performed using the iPhyClassifier software. The results showed that the phytoplasma associated with the symptoms of yellowing and stem fasciation on Japanese spindle shrubs is similar to the Phytoplasma 16Sr-B subgroup with a similarity coefficient of 0.94, and the phytoplasma associated with the symptoms of fasciation of the branches belongs to the Phytoplasma 16SrVI-A subgroup (with a similarity coefficient of 1). This is the first report of phytoplasmas associated with symptoms of fasciation in Japanese spindle shrubs in the east of the country and Razavi Khorasan province of Iran.