Using of Thermotherapy for Elimination of Tristisa virus in Thomson navel orange (Citrus sinensis L.)

Thermotherapy is one of the tristeza management methods that was used in this study. Thus 36 ͺ ‘thomson navel orange’ scions on soure orange rootstocks were placed in temperature controlled chamber (TCC) to investigate the effect of thermotherapy on elimination of Tristeza virus. At first, the scions were inoculated by grafting of infected buds and after six months tested by ELISA to ensure contamination. Plants were placed in temperatures including: 40&30, 42&32, 44&340C for eleven weeks, two weeks and 10 days, respectively. In the last temperature, 12 plants dried and in 6 of the remaining plants, there was not verified any infected by ELISA, Direct Tissue Blot Immunoassay and indicator plant tests after three months from the last experiment.Termotherapy is considered as one of the healthy ways of citrus seedlings depending on plant species and viruses infecting alone or together with shoot tip grafting (STG) leads to the production of healthy seedlings. Healthy subjects express differences in the percentage of low initial concentration of virus. The difference in results between studies and other findings show the need and basis for selecting varieties tolerant to heat.