Open Plantgrape, the official French catalogue of grapevine varieties and clones, and you will find 48 clones listed for Pinot noir alone as of 2026. The catalogue describes clones 236 and 386 as “suited to sparkling wine” and clone 115 as “suited to long ageing”. Within a single variety there are lineages with different characteristics, and growers choose the one that fits their purpose. In most cases, this difference in characteristics is taken to be the reason clones exist.
Yet the system that supports clones today does not rest on those differences. Clonal selection began as a search for yield and uniformity among vines. Once the existence of viruses became known, the framework of the system was rebuilt around disease control. What the current certification system guarantees first is that the material is not infected by viruses. Differences in characteristics sit on top of that foundation.
The technique of propagation and the system of control
In wine grapes, the word “clone” can be found to carry two meanings. One is a mother vine free from pathogenic viruses, together with its progeny. It is propagated vegetatively, as any clone is. Seen from the modern understanding of clones, however, which takes superior traits and characteristics as the selection criterion, this is the clone in a broader sense.
Vegetative propagation means multiplying a grapevine from its canes rather than from seed. It is not a modern invention. There is research indicating that it was already practised before the Common Era.
That research analysed the ancient genomes of grape seeds excavated from archaeological sites in France. Seeds genetically identical to an individual from Martigues dated to 300–200 BCE were found at the Roman-period sites of Mauguio and Lattes. Seeds genetically identical to an individual from Limoges dated to 170–240 CE were also found in a layer dated to 1100–1200 at Valenciennes, about 530 km away. If grapevines grew from seed, each individual would carry a different genotype, and the same genotype could hardly persist over centuries. The discovery of seeds with the same genotype, separated in time and place, is therefore considered evidence that vegetative propagation was practised before the Common Era.
The amount of sequence data recovered in this study was small, however, and it could not resolve differences as fine as those that distinguish clones. What is known is that the same varieties were probably multiplied by vegetative propagation.
What emerged in the modern era was not the technique of propagation. It was a system for testing the propagated vines, assigning them numbers, registering them and controlling their distribution. And this system also gave rise to the concept of the clone.
The nursery industry and viruses
What made that system necessary was phylloxera, which devastated European vineyards in the second half of the 19th century. Grafting onto resistant American rootstocks spread as the countermeasure and became established. Rootstock and scion must be compatible. In addition, because a grafted vine consists of two different plants, the whole cannot be propagated from seed. Against this background, managing the characteristics of individual plants, at a level beyond the variety, became part of modern viticulture.
Once grafting became an industry, young vines changed from something growers multiplied themselves in the vineyard into something specialist nurseries produced and sold over wide regions. Here a new problem arose. Scions taken from a mother vine carry over any viruses the mother vine harbours. As young vines came to be distributed widely, viruses began to spread along the same route.
Grohs and colleagues divide nursery production since 1900 into three periods.
From 1900 to 1950, the central theme was the technique of grafting itself, including the compatibility between rootstock and scion. From 1950 to 2000, the focus shifted to standardising the production process and to sanitary certification aimed specifically at viruses. During this period, public institutions that secured and supplied mother vines of high sanitary status were established in several producing countries. The first international certification programmes appeared in the mid-1950s. From the 2000s onwards, the focus has moved further, from viruses to grapevine trunk diseases.
The beginnings of selection and the rebuilding of the system
Clonal selection began before viruses were known. In Germany in 1876, Gustav Adolf Froelich observed Silvaner vines over several years and propagated only those that gave the most stable and highest yields. The Bavarian State Institute for Viticulture and Horticulture regards this as the first Silvaner clone. In the early 20th century, state and private breeders adopted the method, and a three-stage selection system with performance trials was established. The selection criteria were yield and uniformity among vines.
What changed the course was the discovery of viruses. From the 1950s onwards, it became clear that viruses spread through scion wood, and public institutions and certification systems to secure sanitary status were set up in many countries. In Germany, too, clones were rebuilt in the 1970s on the basis of knowledge about viral diseases, and virus-tested clones came into being.
In France, clonal selection began in earnest within this movement, with the founding of ANTAV (Association Nationale Technique pour l’Amélioration de la Viticulture) in 1962. ANTAV was reorganised as ENTAV in 1986 and merged into IFV (Institut Français de la Vigne et du Vin) in 2007.
IFV attributes the founding of ANTAV to the state of the vineyards after the Second World War. First, viral diseases were widespread. Second, several varieties were often planted mixed in a single vineyard. Third, many hybrid varieties remained that had been created to counter phylloxera and were grown without rootstocks. These three conditions raised the need for clonal selection and led to the founding of ANTAV as a dedicated institution.
The Domaine de l’Espiguette, which became the base for selection, was chosen because of its sandy soil. In sandy soil, nematode-transmitted viruses spread poorly. French clonal selection began first as an effort to secure healthy vines free from viral infection. Until 1990, the only criterion for approving a clone in France was sanitary status.
A genomic study from 2018 records another motive for clonal selection. Before clonal selection became widespread, vineyards were propagated by massal selection (choosing several vines with the desired traits within a vineyard and multiplying them). In such vineyards, genetic variation between vines was large, and fruit quality, yield and vine health were difficult to keep uniform. According to the same study, clonal selection emerged as a technique to solve this. It is described as having served to preserve the qualities of superior vines, to multiply favourable traits and to eliminate viruses.
Being healthy, being true to variety, being uniform in character. Listed side by side, these three are what the system rebuilt around sanitary status required. All of them push towards reducing the differences between one vine and another. Offering a range of lineages with different characteristics to choose from was not part of the system’s purpose.
The EU certification system and the definition of a clone
With Council Directive 68/193/EEC of 1968, the EU laid down rules for the marketing of material for the vegetative propagation of the vine. The material is managed in four categories: initial, basic, certified and standard. What separates the initial, basic and certified categories is the number of propagation steps. As propagation proceeds, material moves from initial to basic and from basic to certified, and the further upstream the material, the more frequent the virus testing required. The standard category carries no obligation of regular virus testing. Even so, standard material must meet requirements for varietal identity and purity, and the visible symptoms of specified viruses must stay below a set proportion. As of 2026, sanitary control remains at the centre of the system’s framework.
The legal definition of a clone took its present form in the 2002 amendment. Under this definition, a clone is “the vegetative progeny of a variety which is true to a vine stock chosen on account of varietal identity, its phenotypic characters and its state of health”.
With phenotype now included among the reasons for selection, the definition established the clone in a narrower sense, based on a more modern understanding. Even with phenotype included, however, a clone is not required to differ from other clones. A variety is registered after examination of whether it is distinct from other varieties, uniform and stable (DUS). A clone, by contrast, is not subject to this examination and is handled in separate lists kept by the Member States. What the definition requires extends only as far as varietal identity.
Since demonstrating a difference is not a condition for registration, comparing registered clones side by side does not necessarily reveal large differences. Researchers who analysed a long-term trial of 30 Riesling clones in Germany found that differences between clones were indeed small, and they gave a reason. Registered clones must not depart morphologically from the type of the variety, so the range of variation available is narrow from the outset.
Does this mean clonal selection does not aim to offer differences? It does not. In a 2017 resolution, the International Organisation of Vine and Wine (OIV) set out the procedure for clonal selection, and it placed among its reasons for adoption the aim to “provide the greatest possible number of clones to wine-growers, with the purpose to provide the greatest possible intravarietal variability/diversity”. IFV likewise states that clonal selection is meant not to reduce the genetic diversity of a variety but to represent it.
The policy of clonal selection is directed towards providing genetic diversity. Still, the principle that the choices sit within the typicity of the variety has not changed. For all the talk of offering diversity, what is selected today remains confined to differences that do not depart from the type.
How far “virus-free” reaches
If the framework of the system lies in sanitary status, it is worth looking at how far that guarantee actually holds.
The certification system uses the fact that nothing was found on testing as its guarantee of sanitary status. What can be found depends on the testing technology. Detection has progressed from grafting onto indicator plants, through antibody-based assays and methods that amplify and detect genetic material, to high-throughput sequencing (HTS), which reads the sequences in a sample comprehensively. The differences between these methods are covered in the article on grapevine viral diseases.
According to a 2023 review, the introduction of HTS revealed cases in which some viruses remained in plants that were supposed to have been freed of viruses through tissue culture and regeneration. This is the result of improved detection making visible what had previously gone unseen. The review states that the effectiveness of these sanitation methods is itself being called into question.
The scope of testing is also limited. The 2017 resolution mentioned above requires testing for three groups of viruses, those associated with fanleaf, leafroll and rugose wood. For the other viruses, listed as a fourth group, it states explicitly that testing “is currently not required”.
“Virus-free” means that no virus was found at the level of testing and within the scope of targets in place at the time. If the level of detection rises, part of the material certified in the past may turn out to have been guaranteed only to the standard of its time.
Summary | What a clone number guarantees
A clone number indicates two things. One is that the vine belongs to a lineage that has passed sanitary testing and viticultural and oenological evaluation. The other is a record of the mother vine from which it descends. Whether in the broad or the narrow sense, the primary meaning of a clone is proof that it does not carry the viruses designated for testing. The framework of the system lies there too. Differences in individual characteristics sit on top of that framework. Moreover, the differences selected lie within the type of the variety.
The catalogue, on the other hand, presents differences in characteristics, such as “suited to sparkling wine” or “suited to long ageing”, as reasons for choosing a clone. Most young vines already on the market meet the fundamental purpose of the clone, which is safety from pathogens. The catalogue descriptions can also be read as a sign that, because this has become taken for granted, the broader reason for the clone’s existence has become a formality. In an era when individual characteristics become the reason for choosing a clone, the system may also be required to move away from a framework rebuilt around sanitary status and respond to those demands.
However, improved testing accuracy has also opened the possibility that clones which met the standard in the past may turn out to be unfit. When that happens, can the soundness that is the primary meaning of a clone be set aside simply because its individual characteristics are excellent?
Clonal selection is said to be most efficient when carried out on vines that have not previously undergone selection, because variation within the variety is easier to find in them. In vineyards replanted in the past with clones that met the standard of their time, new clones become harder to find. If such a clone turned out not to meet the standard after all, there is a route by which it can be supplied again after sanitation. Yet cases have been reported in which viruses remain even after sanitation.
Will the clones in circulation today reliably remain available? If that question raises concern, then the more a vineyard leans on the characteristics of particular clones, the harder future replanting will become.
If being a healthy vine free of viruses holds as a premise, then paying attention to the individual characteristics that sit on top of it is reasonable. Until now, that premise has appeared to hold. The current clone system places the assurance of soundness, not individual characteristics, as its primary meaning. Now, however, it may be necessary to consider that advances in technology could erode the ground on which it stands.
