Genetics in the history of the vine: between prejudice and research into resistant vines

In the history of mankind, science and research have had - and still have - a fundamental role. Not only to answer the questions we ask ourselves every day, but also and above all to resolve the challenges and obstacles that the world confronts us with. This applies to every field, including wine, which - as we never tire of writing - faces perhaps the toughest since civilization began: adaptation to sudden climate change and resistance to vine diseases. Challenges that the vine has already faced in the past, winning the one with the climate, but also losing the one with phylloxera, at least in Europe. In the end, it was always science, or rather genetics, that saved the vine, as Professor Attilio Scienza, professor of viticulture at the University of Milan, told the conference “Towards a new agriculture: the role of genetics and nursery gardening”, which followed the inauguration of the “VCR-Research Center” (in the coming days, the WineNews video, between research and the cuttings market), the futuristic research center of Rauscedo Cooperative Nurseries, attended by Professors Michele Morgante and Andrea Testolin of the University of Udine, Dr. Riccardo Velasco, director of Crea-Ve, and Paolo De Castro, S&D coordinator at the Agriculture Commission of the European Parliament.

“We need to make an effort to get the results of scientific research accepted, we need to publicize and communicate them, otherwise we risk everything we do remaining research locked away in a drawer. To achieve this, we need to break out of the canon, out of the norm, because we are victims of a scientific canon that has conditioned us and conditions us in the way we see the placement of plants within the effort made by Linnaeus, who in his work “Genera Plantarum”, in 1748, introduced the binomial nomenclature and the so-called Linnaean hierarchy, consisting of four categories of descending order: class, order, genus, species”, explains the Professor of Viticulture at the University of Milan. “The genus was for Linnaeus the cornerstone of classification and the criterion for classification was based on the characters of the flower. With Darwin, 100 years later, the classification became descending, natural, evolutionary, starting from a common ancestor and snubbing the value of the species, but for Linnaeus, who was a creationist, as for Darwin, who was instead an evolutionist, the limit was in the definition of species itself”, continues Attilio Scienza.

“A.R. Wallace, a contemporary of Darwin, shared Darwin’s thought and deepened the theory of speciation in its spatial aspects, introducing a then new concept, that of biogeography, according to which the evolution of the species took place over the range that had fragmented as a consequence of the disappearance of portions of land. The most important prerequisites for defining regions of origin were the availability of tertiary fossils, so as to be able to show the changes that had taken place on the surface of the earth, and the genus “Vitis” met these requirements. The climates of the United States (Cold Semiarid, Subpolar, Temperate Semiarid, Temperate Humid, Warm Arid) were found to be the origin of the speciation of the genus “Vitis”. Depending on the different climates, we have Vitis Aestivalis, Vitis Labrusca, Vitis Cinerascentes, Vitis Cordifoliae and so on. If in 1735 Linnaeus had identified two species (Vinifera and Vulpina), Michaux in 1803 described 19, and Kuntze in 1891 made the first organic classification of the genus Vitis. Before him, Planchon had lined up 10 genera and many subgenera, while Baley, in 1934, identified for North America 6 series with 30 species, and Galet, in 1988, described 17 living genera and 2 fossils and 59 species. Today”, continues Professor Attilio Scienza, “the tendency is to reduce the number of species and to include the new species found in China”.

For vine genetics, one of the most important steps concerns post-genomic taxonomy, i.e. “the classifications obtained with the analysis of nSSR,cpSSR, SNP markers, since the 2000s, which have shown that morphological and physiological differences are due to adaptation strategies (ecospecies), how the analysis of molecular traits (nuclear and chloroplastic) suggests the absence of a clear separation between Asian and American species (monophyletic origin), and therefore that the first divergence occurred in Asia and then between Europe and the USA. Studies on the speciation of the European grapevine, and therefore on the transition from Cissus to Vitis Sylvestris, suggest that a link between the two species can be identified in a geological phase between the Paleocene and Eocene (65-55 million years ago), during which the continents were still interlocked. The perfect interlocking”, Professor Attilio Scienza recalls, “was 250 million years ago, when they had already begun their estrangement (the Drift of the Continents), which would lead to the world as we know it today, allowing American and Eurasian types to coexist in Europe. The latest studies have been carried out by botanists, mostly Chinese and North American, who tell us that the genetic proximity of our wine vines is more with the American than with the European one”.

The question, then, is: where are the differences between American and Asian species? The classic distinction between the species, explains the Professor of Viticulture at the University of Milan, “is the result of ampelographic evaluations. Between the American species and the European vine, the distinction was based on the presence of two berry metabolites, ethylantranilate and malvidin di-glucoside. The common origin of the Asian and American species has recently been demonstrated by plasmid DNA analysis, which hypothesizes the primary center of origin of the genus in America and subsequent migration to Eurasia”. In short, there are no real discriminating factors between the American and Eurasian species, which are linked from the beginning and are the daughters of cross-breeding that - despite the prejudices of science itself, which have lasted a century, living in the myth of the purity of species and race - is the true salvation of the vine. This is evidenced, for example, by “the anthranilate, cinnamate and furaneol esters responsible for the foxy aroma of certain American species (essentially Vitis Labrusca and its hybrids and Vitis Rotundifolia), substances which have also been detected in Pinot Noir, and which are responsible for the fruity and berry notes of Burgundy wines: The two genes coding for the synthesis of anthranilates are differentially expressed in Vitis Labrusca and Vitis Vinifera, but the differential expression in the two species is precisely the result of mutation (from transposable elements) or genetic recombination”, explains Attilio Scienza.

In essence, genetics tells us a great deal, if not everything, about an individual and a species, be it a human being or a variety of lives, but in the past it has known the degeneration of its excesses, namely eugenics, which since the end of the nineteenth century has driven many scientists to the obsessive pursuit of species improvement, in a pursuit of purity and perfection that has little or nothing to do with human, animal and plant life. Eugenics, in this sense, “is the foundation of racism: invented by the English statistician Francis Galton, Darwin’s cousin and inspired by his work, in 1859, it was based on the concept that natural selection ensures the diversity of species and the survival of the fittest individuals, while at the same time eliminating the less fit, which should also occur, at a social level, with respect to intellectual characters”, resumes Attilio Scienza. That it was a degenerate science is testified, among many, many, by the words of Nobel Prize winner Richter who, in 1919, in the pages of “La Selection Humaine”, wrote: “after the elimination of inferior races, the first step in the path of selection is the elimination of abnormals”. In 1924, Agostino Gemelli, founder of the Catholic University, on the occasion of the First Congress of Social Eugenics, claimed that eugenics represented a precious conquest in continuous development, in an interpretation of the human being radically contrary to the Christian one”. Today, fortunately, we can espouse, without doubt, the maxim of Luigi Luca Cavalli-Sforza, who in his “Introduction to Human Genetics” in 1976, wrote: “Races exist not in our genes, but in our heads, in the societies in which we live”.

“There are, on closer inspection, many similarities between racism and discrimination between Vitis species, because for a long time physiognomy was the basis of eugenics to determine the characters of discrimination between human races, just as methyl-antranilate and malvidin di-glucosides are the chemical compounds used to discriminate American species from European vines, with many scientific studies supporting the harmfulness of the American vine”, says the Professor of Viticulture at the University of Milan. A great insight into how, rather than purity, it is precisely cross-breeding that guarantees the continuation and improvement of the species, comes from the V International Congress of Vine and Wine, in 1938, when Professor Husfeld of the Kaiser Wilhem Institut presented his research “Genetics in Viticulture”. “Through what he calls “inbreeding” (self-fertilization) of Riesling he obtains 20 million seeds, and by subsequent cross-breeding between resistant vines he arrives at 10 million seeds, from which he obtains 7 Riesling plants that tolerate downy mildew. This report was strongly contested by the French, while in Germany - to understand the spirit of the times - the government was preparing to promulgate racial laws. As if that were not enough, an American bombing raid on the greenhouses of the Kaiser Wilhem Institut in Muencheberg (Berlin) in 1943 destroyed the precious tolerant vines, but in the meantime, the existence of resistance genes in Vitis Vinifera had been empirically demonstrated”.

Since then, there has always been a certain amount of ostracism towards “hybrids”, which finally seems to be changing. “In France, in 1937, they were opposed because of the growing role they played in national wine production, and in Germany in 1938, as we have seen, they enjoyed very little popularity in the wake of the racial laws”, says Attilio Scienza. “This unpopularity lasted for decades, so much so that in 1974, in France, varieties resulting from cross-breeding were renamed “mestizos” to distinguish them from the old hybrids. In this context, the 1979 OIV resolution presented by Germany to authorize the cultivation of quality hybrids in the EEC will be fundamental. Today we can safely say that the hybrid will save viticulture, because the territorial discontinuity between the American species and the European vine and the agamic multiplication in viticultural practice prevent the spontaneous creation of resistant plants between the different species of the Vitis genus, but with the traditional genetic improvement by cross-breeding and that with the new technologies, these otherwise impassable natural barriers, which prevent natural evolution within the genus, are overcome. This fulfils Mendel’s prophecy and dream: genetics is the evolution in the hands of man”.

And yet, even today the wine myth is identified in many contexts with the concept of purity, which has first and foremost a religious significance: “to cross different species with the European vine is to contaminate the natural state of the grape, to contaminate those who produce that wine and those who consume it, it is to break that link between classical tradition and contemporaneity. Through the purity of wine made from the European vine, esoteric movements aim to restore that link between religion and wine and through this to make nature take on a higher state in order to prepare it for a relationship with the mystery. The search for varietal purity in a wine recalls the principles of so-called natural and biodynamic viticulture, through the ideological rejection of modern enology as an alchemic workshop”, explains Attilio Scienza, according to whom “the anthropological acceptance of resistant vines carries the weight of history and myth, because wine is a symbolic object, containing abstract values that are fundamental to our culture, it is endowed with a symbolic efficacy capable of producing predictable and repeated responses such as pleasure, deviance, arousing elegance, refinement. Wine is a totem drink, a myth (a tale by etymology), a social value (in relation to communication), it recalls values that are not far removed from the ideal of man: beautiful, healthy, intelligent, which even eugenics wanted to preserve from racial contamination. But why are we not shocked”, asks Scienza, “when we eat an apple, another mythical object in Western culture, which is the result of crossing (or hybridizing) the Malus Sieversii from Kazakhstan with Malus Sylvestris and Malus Orientalis? In the future”, concludes Professor Attilio Scienza, Professor of Viticulture at the University of Milan, “communication will play an essential role in defending the value of the resistant from false science, which is the source of denialism and the contemporary phenomenon of No Vax”.