WINETECH Technical Yearbook 2021

health benefits of the resistant wines, consumers in fact scored these novel cultivars higher than traditional cultivars in a general quality assessment. This speaks volumes for the impact the origin story has on the perception of wines, and on the consumer’s interest to minimise their environmental footprint and maintain a healthy lifestyle. Clearly well thought out marketing strategies are going to be crucial in the promotion of novel wine cultivars. Currently it is foreseen that these resistant cultivars will for the most part be used in blends and will seldom be sold as single varietal wines. The primary reason for this is that often the typical quality traits of these cultivars are somewhat lower than that of traditional cultivars. This, together with the time-consuming nature of breeding, are the two major obstacles scientists are focusing their energies on to breed varieties that can stand on their own as premium resistant cultivars. FIGURE 2. Photograph of the microvine, showing berr ies at mul t iple stages of development. The microvine does not develop tendrils, and instead forms bunches as early as five months after seedlings are planted. (Image courtesy of Laurent Torregrosa of Institut Agro Montpellier, France).

As DNA markers were discovered and used to track and incorporate resistance traits, similar work is now being performed for quality traits. DNA markers for berry size and colour, seedlessness, anthocyanin and aroma formation have already been developed. Breeders can now choose to incorporate (or not) the genetic elements responsible for the classic Muscat aroma derived frommonoterpenes, or the peppery aroma of Shiraz, in their novel cultivar. Much work remains to be completed in this sphere as currently only a handful of markers exist. However, as scientists discover and develop more and more DNA markers for quality traits, we will move toward a situation whereby a breeder can select from a library of thousands of traits, and provided they have the germplasm at their disposal can plan a breeding strategy that will result in a spectrum of not only resistance traits, but also quality traits being targeted for inclusion in the final cultivars. While advances in this field are being made every day, the issue of time remains. Regardless of the amount of genetic knowledge scientists generate, it will still take time to work through the cycles of breeding to get to the desired outcome. Indeed, the more traits one wishes to include, the more breeding cycles are likely

to be required. One exciting shortcut that has been developed that may accelerate this process, is the “microvine” (figure 2). Instead of the usual five to six years it may take for regular grapevine to produce fruit, the microvine produces its first fruits five to six months after the planting of seedlings. By incorporating microvine into their breeding programmes, breeders are therefore able to dramatically speed up the breeding process: up to 10 generations can now be grown in the time it would usually have taken to grow one. Currently microvine only exists in the Pinot noir background, meaning that all crosses made with this system will be crosses with Pinot noir. Research aimed towards generating microvine in other cultivar backgrounds would dramatically increase the scope of this tool. Armed with these new technologies breeders are far better positioned to meet the ever-growing consumer demand for more sustainable agriculture, while still maintaining a high quality product. We may be some way from the romanticism of the Perold approach, but we have more than made up for that with the scientific advancements of the last 30 years. South African researchers and breeders are now in a position to build on the ongoing international efforts and knowledge, and

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