Dr. Asia Khafizova, VCR Rauscedo, Italy
The issues of sustainability of wine production are the subject of increasing attention by the public opinion and the operators of the vine&wine supply chain worldwide. In 2006 the Vivai Cooperativi Rauscedo (VCR) had perceived the need to give concrete answers to the emerging requirements in terms of nursery-viticultural sustainability. For this reason, they started a fruitful collaboration with the University of Udine and the Institute of Applied Genomics with the aim of providing vine-growers with new wine grape varieties resistant to the most dangerous diseases. The first ten resistant Italian varieties, of which VCR is exclusive licensee, were created thanks to a research activity started in 1998 by the University of Udine. VCR actively participated in the last stage of this project, evaluating agronomic and enological traits of the new resistant varieties, which led to their registration in the National Catalogue in 2015: Fleurtai, Soreli, Sauvignon Kretos, Sauvignon Nepis, Sauvignon Rytos, Mertot Kanthus, Merlot Khorus, Cabernet Volos, Cabernet Eidos, Julius, and their subsequent distribution in Italy and abroad. Today, after having reached this first goal, the evaluation is focused on 7 new varieties, still created by the University of Udine from the crossing of Pinot Noir and Pinot Blanc with new and more performing resistance donors. The following varieties will be registered in the National Catalogue: 109-033 (Pinot blanc type), 109-052 (Pinot blanc type), 156-537 (Pinot noir type), 156-312 (Pinot noir type).
The wines of the resistant varieties were presented by VCR at the International PIWI Wine Award in 2017 and 2018. All the wines presented were awarded with gold (Merlot Kanthus, Merlot Khorus, Pinot noir type 156-537, Sauvignon Rytos) and silver medals. "In all cases, these are exceptional and flattering results - commented Professor Raffaele Testolin, one of the professors of the University of Udine who started the project for the establishment of resistant varieties - also because they were completely unexpected, demonstrating the high potential of the new varieties for the high quality wine production."
In the four-year period 2015-2018, grapes from the experimental plots located in different Italian and foreign regions were vinified at the VCR Experimental Centre Winery and at some national and foreign research Institutes: Abruzzo, Puglia, Tuscany, Marche, Veneto, Friuli VG, Sardinia, Lombardy, Piedmont, Sicily, Emilia-Romagna, Slovenia, France, Spain, Germany, Czech Republic, Russia. The varieties have been placed in experimental fields according to their cultivation aptitudes in different environments and in view of their possible inclusion among the varieties authorized for cultivation. The enological results obtained with the vinification of the new disease-resistant varieties are fully comparable, if not even superior, to those obtained from the V. vinifera parents, so that in blind tastings the wines of resistant varieties were not distinguishable from the parent varieties. In addition, due to their resistance to low temperatures (for some varieties up to -24°C), the registered varieties can also be used in marginal areas of viticulture, offering farmers a more profitable possibility of using them.
In 2015, VCR also launched its own breeding program to obtain new resistant varieties of wine grapes, table grapes and rootstocks. Particular attention has been paid to indigenous varieties and their clones, which represent the strength of Italian viticulture and which, with the introgression of genes of resistance to downy mildew and powdery mildew, could truly constitute a unique opportunity for the winemakers. The creation goal of these new “Autochthonous Improved Varieties” (VAMs, it. Varietà Autoctone Migliorate) is to combine tradition and innovation in their DNA: wines with an aromatic and polyphenolic profile of comparable quality and typicity to V. vinifera's parent. In the near future, resistant varieties from traditional varieties such as Glera, Nebbiolo, Sangiovese, Cannonao, Trebbiano Romagnolo and Toscano, Malvasia Istriana, Riesling Bianco, Chardonnay, Pinot Grigio, Syrah, etc. will be available on the market.
Protection strategy of resistant varieties. Understanding the concept of resistance and the related mechanisms of action is very important in order to better manage this specificity, which is unique to the new resistant varieties, and to prepare an ad hoc defence strategy. The sources of resistance to cryptogamic diseases are found in the species of wild Vitis, the American and Asian species, as well as in some varieties of V. vinifera from Central Asia. Today more than 30 QTL (Quantitative Trait Locus) responsible for resistance to downy mildew and powdery mildew are known and others are being studied and will be identified soon. The goal is to pyramidise 2-3 resistance genes to downy mildew and powdery mildew respectively in each of the new resistant varieties selected. The creation of vines with polygenic resistance is important to exclude any risk (even if almost improbable) of overcoming the resistance, that we could observe in vines with monogenic resistance. The presence of several genetic barriers to overcome complicates, in fact, the attempts of the downy mildew and of the powdery mildew to infect the vine thus ensuring a perennial high resistance to these cryptogams. For the 10 resistant varieties currently authorized for cultivation we recommend 2-3 treatments per year to be carried out following the provisional models for the identification of the periods of greatest infectious risk. These precautionary treatments are essential to prevent the appearance of hypervirulent forms of pathogen and to protect the vine from secondary diseases (Phomopsis, black rot, anthracnose), normally controlled by the same active ingredients used for the control of downy and powdery mildews. It is necessary to specify that secondary diseases can also be observed on traditional varieties in total absence of phytosanitary protection.
Despite the very high costs and the long times required for genetic improvement programs, the Vivai Cooperativi Rauscedo are firmly convinced that the road taken is the most concrete and safe way to make world of viticulture a more sustainable and environmentally-friendly and less dependent on use of plant protection products.