Essential oil components of Citrus cultivar‘MALTAISE DEMI SANGUINE’ (Citrus sinensis) as affected by the effects of rootstocks and viroid infection

ABSTRACT ‘Maltaise demi sanguine’ cultivars are usually grafted on sour orange rootstock. Nonetheless, this rootstock is highly susceptible to Citrus tristeza virus (CTV). A trial was set up in order to present new rootstocks as an alternative to sour orange. The effects of eight citrus rootstocks upon the volatile flavor components of the “Maltaise demi sanguine” peel were investigated in both healthy plants and those inoculated with Citrus exocortis viroid (CEVd) and Hop stunt viroid (HSVd). Rootstocks and viroid infection had no significant effect on essential oil yields. Oil components were analyzed by GC-MS. Total of 69 compounds were identified, representing 99% of the total oil. Limonene was the major component in all samples (59.53–95.34%). Principal components and hierarchical cluster analyses revealed that essential oils from plants grafted on Alemow and Carrizo citrange showed the most variable compositions in cases of healthy plants and those inoculated with CEVd. For those plants infected by HSVd, Cleopatra mandarin seemed to be the most affected. Overall, the combined effect of CEVd infection and the use of rootstocks Alemow, Carrizo citrange, and Volkamer lemon had the most pronounced chemical variability