AxR1 is a grape rootstock once widely used in California viticulture. Its name is an abbreviation for "Aramon Rupestris Ganzin No. 1", which in turn is based on its parentage: a cross of Aramon, a Vitis vinifera cultivar, with Rupestris Ganzin, a selection of the American grape species, Vitis rupestris.

It achieved a degree of notoriety in California when, after decades of recommendation as a preferred stock, its resistance to phylloxera broke down in the 1990s, resulting in the failure of a number of vineyards and requiring extensive replanting. Agriculture