Grape Phylloxera

Vitis vinifera cultivars are characterized by an incomplete life cycle of the pest without the formation of leaf galls. The primary damage is caused by the root form, whose activity triggers the formation of swellings that are colonized by pathogenic fungi and bacteria, leading to the decay of the root system.

External symptoms include leaf dwarfing and yellowing, reduced shoot growth, and premature leaf drop. Affected areas often spread in circular patches from the primary infestation center.

European grape varieties lack natural resistance, so breeding is conducted through the introgression of Rdv genes (from Rdv1 to Rdv8) derived from American species. To evaluate the material, a scoring scale is used, where 0 points corresponds to immunity, precluding the formation of galls on the roots.