Sources of resistance exist in Prunus, but are not abundant. This provides a unique source of germplasm for future breeding programs worldwide. Similar success has not yet occurred in attempt to genetically modify other Prunus species, although these efforts are ongoing. In peach, infected trees may exhibit color-breaking symptoms in the blossoms. This appears as darker pink stripes on the flower petals and can be useful for early season surveys.
Some trees show no symptoms on leaves or fruit.
In Chile, several of the infections have been asymptomatic, and infection were discovered only through rigorous testing of trees. Not all infection in Prunus are characterized by a ring symptom on leaves. Several cultivars show yellowing line patterns and blotches, or necrotic ring symptoms on expanded leaves. Leaf distortion has also been observed. The leaves of some peach trees in France infected with plum pox produce a yellowing vein clearing that turns necrotic and causes leaf drop.