مهدی بنی هاشمیان
رضا فیفایی
حشمت الله رحیمیان
یونس ابراهیمی

Citrus Trisateza Virus is one of the most important diseases of citrus and its damage was reported from many regions in the world. It is a great threat to citrus industry in Iran that its common rootstock is sour orange. The aim of this reaserch was study the tolerance of five natural hybrid rootstocks to citrus tristeza virus. These hybrids were Shell mahaleh, Khoram abad lemon, Ramsar lemon hybrid, Off type sour orange and natural Kotra hybrid. At first 16 seedlings of each hybrid were selected and divided into two groups. The first group was grafted by free disease Thomson navel nucellar and the second group remind in seedlings form. In order to inoculation 4 seedling of every group were grafted by five infected buds and the others were without inoculation. Result showed that Thomson novel on Natural Kotra hybrid, Shell mahalleh, Khoram abad lemon hybrid, Ramsar lemon hybrid and Shell Mahalleh seedling and Natural Kotra hybrid seedling had Stem pitting and leaf symptoms. They were tested by ELISA. Finaly we found that natural Kotra hybrid, Shell mahalleh, Khoram abad lemon hybrid are fairly tolerant, Off type sour orange is tolerant and Ramsar lemon hybrid is susceptible to Citrus Tristeza Virus.