The effect of Pyramiding resistance control genes on viral disease of Tomato yellow leaf curl virus (TYLCV) on enzymatic and non-enzymatic defense systems in different lines

Tomato yellow leaf curl viral disease (TYLCV) is one of the main limiting factors that has caused great damage to tomato crop in tropical and subtropical regions of the world. Several genes have been identified from various sources that cause plant resistance to TYLCV virus disease and have been integrated into tomato crop genotypes. Pyramiding of these genes can lead to Stable resistance and, in addition, Causes resistance to several strains of the virus. The results of this study showed that viral infection increases the level of phenol and flavonoid compounds as well as antioxidant enzymes in the host plant, while lines containing the Ty-2 and TY-1/3 genes They had lower synthesis and expression of non-enzymatic antioxidant compounds (phenol and flavonoids) and antioxidant enzymes (catalase, peroxidase, guaiacol peroxidase and polyphenol oxidase). Also, in the study of TYLCV virus genome concentration using quantitative polymerase chain reaction technique, it was observed that the lines containing two Ty-2 and TY-1/3 compared to control plants had the lowest rate of the virus genome. This matter indicates the low rate of virus replication in the host plant. According to the observations of this study, by combining different TY genes, a desirable level of resistance in desirable but sensitive tomato lines against TYLCV virus can be achieved.