Introgression Among Cultivated and Wild Grapevine in Tuscany

Abstract

Wild grapevine, Vitis vinifera L. subsp. sylvestris (Gmelin, Hegi) is spontaneous to Europe and common in Tuscany. In this study, wild grapevines were identified in 22 populations from eight locations in Tuscan Maremma (Grosseto and Siena province). The plants were propagated by cuttings, collected in a vineyard, genotyped by nuclear simple sequence repeats (SSRs), chloroplast SSRs and single nucleotide polymorphisms (SNPs), and compared to locally cultivated varieties (Vitis vinifera L. subsp. sativa) and to non-vinifera and non-vitis genotypes. The identity analysis revealed that some individuals were redundant genotypes, suggesting natural vegetative propagation. In addition, four of the supposed V.v. sylvestris were in fact naturalized V.v. sativa. The majority of putative sylvestris genotypes had chlorotype A, while the remainder had chlorotype D, as the majority of Vitis vinifera subsp. sativa cultivated in Italy. Some of the recovered sylvestris genotypes appeared to be natural crosses with cultivated grapevine varieties in Tuscany, and their chlorotype suggests a higher pollen flow from sativa to the sylvestris genotypes than in the opposite direction. In addition, other genotypes appeared to be crosses within sylvestris, sylvestris-sativa or sylvestris-sylvestris siblings, or equivalent relationships. These relationships suggest a noticeably level of sexual reproductive activities among sylvestris and sylvestris-sativa genotypes. A cluster and structure analysis clearly differentiated the true sylvestris from the sativa, and the nonvinifera or non-vitis genotypes, and also highlighted a possible introgression of sylvestris into some Italian and French cultivated varieties. The results therefore suggest that, in addition to the primary ancient center of domestication from the Near East to Central Asia, the introgression among cultivated and wild grapevine occurred in other centers of diversification along the migration routes, contributing to the domestication processes, and suggesting that these processes are still ongoing despite the reduction in populations of sylvestris. The results also highlight that the GrapeReSeq 18K Vitis genotyping chip are suitable for non-vitis genotyping and that the range of SNPs heterozygosity in sylvestris appears to be up to 6% less and does not overlap the heterozygosity range of sativa genotypes.

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

“…Genetic diversity in the studied set of individuals, expressed through the expected and observed heterozygosities of SSR markers, was greater in vinifera than in sylvestris, as seen in previous studies [9,16,18,20]. Among sylvestris populations, the greatest heterozygosity was observed in P06 (Croatia) and the lowest for P08 (Germany), indicating heterozygosity decreased from east to west.…”

“…Cultivated varieties clustered together with wild grapes from the same area in Georgia [14]. There was introgression of Italian wild grapes in the genome of some Italian cultivated varieties, in particular some local Tuscan varieties [20]. The relatively isolated Sicilian pool of wild populations was closely related to the local cultivated germplasm [9].…”

“…Wild and cultivated grapevines form a genetic and taxonomic continuum, resulting in spontaneous hybrids [16]. Cultivated grapevine has greater overall genetic diversity and heterozygosity than wild [14,16,20] due to the fact that, during domestication, a large diversity was preferred (e.g., berry shape, aroma, yield) which ultimately favors heterozygosity. The grapevine was distributed very early following ancient trade routes that contributed to the development of a large number of varieties.…”

Population genetic analysis in old Montenegrin vineyards reveals ancient ways currently active to generate diversity in Vitis vinifera

“…Wild MNE 359 samples were found extremely close in the municipality of Gornji Ulići, so it is probable that both samples were inadvertently taken from different branches of the same individual. Wild MNE 273 samples were found at the two sides of a road in Crmnica, suggesting the occurrence of natural vegetative multiplication 41 .…”

DNA-based genealogy reconstruction of Nebbiolo, Barbera and other ancient grapevine cultivars from northwestern Italy

“…When applied on a large scale, genotyping offers information about cultivated grapevine genetic clusters 14 – 18 , and relation between currently cultivated varieties and wild Vitis vinifera subsp. sylvestris genetic pool 19 – 23 . In turn, this provides insight into domestication processes and helps us trace the evolution and dissemination of viticulture and wine culture.…”