بررسی نقش ویروس رگبرگ روشنی زرد مرکبات در بروز لکه‌برگی نارنگی کلمانتین

Citrus yellow vein clearing virus (CYVCV) is a new species from the genus Mandarivirus. It has spread rapidly in the neighboring countries of Pakistan, India, Turkey and China. The virus has recently been reported in Lemon (Citrus limon), sour orange (C. aurantium) and Persian lime (C. latifolia) from Iran. Vein clearing and yellowing with corresponding water-soaked appearance of the lateral veins on the lower surface of the leaves are symptoms of the virus in the susceptible hosts. Such leaves are defoliated or remain on the tree. According to recent studies, Citrus yellow vein clearing virus was associated with ring spot symptoms in different citrus varieties. Ring spot symptoms were noticed in several Clementine (C. clementina) trees in a Persian lime plot infected with yellow citrus yellow vein virus in Mazandaran province. Nucleic acid extraction was conducted from young tissues of the infected trees by SDS-Potassium acetate method. A two-step Reverse Transcription Polymerase chain reaction (RT-PCR) was carried out using Revert Aid Kit (Fermentas), PCR Master Mix (Fermentas) and CYVCV specific primer pair of coat protein gene. A target PCR product with around 600 bp was obtained. Transmission of the disease was confirmed by graft inoculation of healthy clementine plants with tissues from the infected trees in the greenhouse condition. Ring spots symptoms were appeared on leaves of clementine plants after using sour orange infected with CYVCV as a source of inoculum. On the other hand, the virus-specific symptoms were obtained after grafting healthy sour orange buds onto infected clementine trees.