Characterization of Tobacco Mosaic Tobamovirus (TMV-S) Isolated from Sunflower (Helianthus annuus L.) in Egypt

This is the first record of Tobacco mosaic Tobamovirus (TMVS) on sunflower in Egypt. It was originally isolated from naturally infected sunflower plants growing in Giza Research Station, showing systemic mosaic and spots. Both morphological characters and seed yield were reduced significantly as a result of virus infection. The effect of treatment with the virus was negative in all irradiated Sakha genotype developed through irradiation with 100, 200 and 300 Gy, as well as and Giza 102 genotype developed through irradiation with 100 Gy, because these genotypes tend to be resistant to TMV-S as ELISA test reported.