Grapevine rootstocks: origins and perspectives
Résumé
Grapevines were propagated from cuttings up until the late 19th century when the soil-borne aphid phylloxera (Daktulosphaira vitifoliae [Fitch]) destroyed Vitis vinifera L. vines grown on their own roots. The damaging import of grape phylloxera to France in 1868 led to extensive international research and collaboration to save European viticulture. Numerous growers, breeders and scientists played important roles in the historic campaign against the grape phylloxera and in finding the solution to this problem, which ultimately lay in grafting European vines on American rootstocks. Nowadays, more than 80% of the vineyards worldwide use grafted plants: a scion of V. vinifera grafted onto a rootstock of single American Vitis species or interspecific hybrids of Vitis species that combine desirable features of their parentage. The majority of rootstocks used today were bred at the end of the 19th century or at the turn of the 20th century. They are mainly hybrids of four species: V. berlandieri, V. riparia, V. rupestris and V. vinifera, but secondary species have also been used. In addition to phylloxera, rootstocks contribute to the control of other soil-borne pests such as nematodes and to various abiotic constraints such as drought, salinity, limestone and mineral nutrition problems. They also strongly interact with scion genotypes and modify whole plant development, biomass accumulation and repartition, and phenology. In the context of climate change, they may be considered as a key element of adaptation. Rootstock breeding programs in the main grape growing countries around the world aim to improve pest resistance and adaptation to abiotic stresses. This article will give an overview of the history of rootstock use in the world, a brief description of the main rootstocks cultivated and some details on current breeding programs.