Coat protein sequence analysis of Iranian Hosta virus X (HVX) isolates

During the spring of 2011، several symptomatic hosta plants Hosta sieboldiana with mosaic، mottling and leaf deformation were observed in commercial hosta propagation greenhouses and gardens in Karaj and Tonekabon regions in Iran،. A total of 17 symptomatic samples were collected and tested for the presence of Arabis mosaic virus-ArMV، Cucumber mosaic virus-CMV، Tomato spotted wilt virus- TSWV، Impatiens necrotic spot virus-INSV and Tomato ring spot virus-ToRSV by DAS ELISA method. None of the tested samples had positive reaction with any of the antibodies. Some of symptomatic samples induced necrotic local lesions on Gomphrena globosa indicator plant in mechanical inoculations without inducing any symptom on other inoculated plants. Samples were tested for Hosta virus X (HVX) infection by reverse transcriptase polymerase chain reaction (RT-PCR) using specific primers designed for coat protein (CP) gene in this study and a DNA fragment with the expected size about 700 bp was amplified. CP sequences of Iranian HVX isolates showed 98. 5 – 99. 5 % nucleotide identity with 55 other non-Iranian HVX isolates. This is the first report of HVX occurrence in Iran and CP nucleotide sequence of five Iranian HVX isolates was determined.