Out of the 23 vine species, only some of them show any resistance to the phylloxera
(Dactulosphaira vitifoliae), mainly Vitis Rupestris, V. Berlandieri and V. Riparia.
From the crossing of one of these species, or of these species and others, there
has been obtained the majority of the mother plants that have been used in Europe
since the plague occurred. Other species, like V. Champinii, is characterized
by a greater resistance to nematodes and it has been another of the means of obtaining
mother plants by crossing.