Reintroduction of Vitis vinifera subsp. sylvestris (wild grapevine) in the Kühkopf floodplain between 2015 and 2017

Das Naturschutzgebiet Kühkopf-Knoblochsaue mit 2 400 ha überflutbarer Aue eignet sich in dem potenziellen Wildreben-Verbreitungsgebiet in Deutschland (Oberrheingebiet zwischen Freiburg und Wiesbaden) aktuell bei weitem am besten zum Wiederaufbau überlebensfähiger, ausreichend heterozygoter Wildrebenbestände. Nach einer ersten Wiederansiedlung 2013 mit 65 Genotypen und 121 ausgebrachten wurzelnackten Pflanzen mit Draht-Verbissschutz wurden 2016 in einer zweiten Wiederansiedlungsmaßnahme 551 Wilde Weinreben (78 Genotypen) an 12 Standorten gepflanzt. Es handelte sich hierbei um zweijährige Topfpflanzen, die ohne Verbissschutz gepflanzt wurden. Ein Jahr nach der Pflanzung war eine durchschnittliche Überlebensrate von 69 % zu konstatieren. Die Überlebensraten variieren an den Standorten zwischen 55 und 87 %. 75 von Wildschweinen herausgewühlte Wilde Weinreben wurden wieder eingepflanzt; die Überlebensrate kann somit noch über 69 % steigen.The Kühkopf-Knoblochsaue nature reserve, with an area of 2,400 ha, is periodically flooded. It is located in the potential range of the European wild grapevine in Germany (Upper Rhine Valley between Freiburg and Wiesbaden). The nature reserve currently provides favorable conditions for reintroducining a viable, sufficiently heterozygous population. In 2013, we repopulated the nature reserve with 121 wild grapevine plants (65 genotypes), which were transplanted directly from a botanical garden. The plants were protected by wire from potential damage caused by game. A second repopulation measure in 2016 involved the transplantation of 551 plants (78 genotypes) at 12 different sites. For this second measure, we grew the wild grapevine plants in pots for two years and wire was not used for protection. One year later, the mean survival rate was 69 %, varying between 55 % and 87 % among sites. The 75 plants removed by wild boar were replanted. The survival rate may therefore exceed 69 %

Genetic Structure and Relationships among Wild and Cultivated Grapevines from Central Europe and Part of the Western Balkan Peninsula

The genetic diversity and relationship between wild (Vitis vinifera L. subsp. sylvestris (Gmel.) Hegi and cultivated (V. vinifera L. subsp. vinifera) grapevine in the western Balkan region and Central Europe have not been studied together previously, although this area has a rich viticultural past. Here, we studied wild grapevine populations sampled from their natural habitats in several countries of the western Balkan region and Central Europe. Their genetic diversity and structure were compared to cultivars that are traditionally in use in this region. A sample set of 243 accessions was genotyped at 20 nuclear microsatellite loci, including 167 sylvestris and 76 diverse vinifera cultivars. The genetic diversity of the wild grapevines was lower than that of cultivars by all genetic parameters. Both hierarchical and nonhierarchical clustering methods differentiated two main groups, indicating clear separation between wild and cultivated vines but also revealed clear gene flow between the cultivated and wild gene pools through overlaps and admixed ancestry values in the graphs. There was greater affinity to the wild grapes in Central European cultivars than in Balkan cultivars. Fine arrangement of the structure among cultivated grapevines showed differentiation among Central European and Balkan cultivars. These results confirm the divergence of wild grapes from vinifera and highlight the “crossroad” role of the western Balkan peninsula in the broader context of European viticulture