Authors : Neda Rafizadeh, Behrouz Jafarpour, Mehdi Nasr Isfahani and Mahrokh Falahati Rastegar
Abstract: The Iris Yellow Spot Virus (IYSV) is one of the diseases of Iris plants in Iran, occurring annually and causing considerable losses. In this manuscript, the molecular and serological studies of the disease were taken placed for the 1st time in Iran. For this purpose, 435 samples with symptoms of chlorotic, necrotic and diamond shape lesion were collected from onion fields and 142 from ornamental plants. The infected plants were transferred into the laboratory for DAS-ELISA tests and the sap of positive plants inoculated to 4 indicator host plants Nicotiana rustica (with leaf deforming and systemic chlorotic and necrosis), N. benthamiana, N. clevelandii, N. tabacum var. samson (with systemic chlorotic and necrosis) in greenhouse conditions. The inoculated indicator plants tested for DAS-ELISA then sap of positive indicator plants inoculated to 4 onion genotypes, neishabour yellow, neishabour white, dargaz red and isfahan red (Dorche). Also for genetical analysis, the RNAs were extracted by PEG6000 precipitation and RNXTM (plus) kit. In RT-PCR tests, specific primers designed for nucleoprotein gene amplified 181 and 139 bp fragments. It was found that all of the onion fields were infected with the virus in various degrees, out of which IYSV was detected in 107 samples of onion, 7 samples of chrysanthemum flowers and a sample of Iris flowers.
Neda Rafizadeh, Behrouz Jafarpour, Mehdi Nasr Isfahani and Mahrokh Falahati Rastegar, 2012. Molecular and Serological Studies of Iris Yellow Spot Virus on Onion Plants in Iran. Agricultural Journal, 7: 180-186.