AUTHOR=D’Onofrio Claudio 

TITLE=Introgression Among Cultivated and Wild Grapevine in Tuscany

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.00202

DOI=10.3389/fpls.2020.00202

ISSN=1664-462X

ABSTRACT=<p>Wild grapevine, <italic>Vitis vinifera</italic> L. subsp. <italic>sylvestris</italic> (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 (<italic>Vitis vinifera</italic> L. subsp. <italic>sativa</italic>) and to non-<italic>vinifera</italic> and non-<italic>vitis</italic> genotypes. The identity analysis revealed that some individuals were redundant genotypes, suggesting natural vegetative propagation. In addition, four of the supposed <italic>V.v. sylvestris</italic> were in fact naturalized <italic>V.v. sativa</italic>. The majority of putative <italic>sylvestris</italic> genotypes had chlorotype A, while the remainder had chlorotype D, as the majority of <italic>Vitis vinifera</italic> subsp. <italic>sativa</italic> cultivated in Italy. Some of the recovered <italic>sylvestris</italic> genotypes appeared to be natural crosses with cultivated grapevine varieties in Tuscany, and their chlorotype suggests a higher pollen flow from <italic>sativa</italic> to the <italic>sylvestris</italic> genotypes than in the opposite direction. In addition, other genotypes appeared to be crosses within <italic>sylvestris</italic>, <italic>sylvestris</italic>-<italic>sativa</italic> or <italic>sylvestris</italic>-<italic>sylvestris</italic> siblings, or equivalent relationships. These relationships suggest a noticeably level of sexual reproductive activities among <italic>sylvestris</italic> and <italic>sylvestris</italic>-<italic>sativa</italic> genotypes. A cluster and structure analysis clearly differentiated the true <italic>sylvestris</italic> from the <italic>sativa</italic>, and the non-<italic>vinifera</italic> or non-<italic>vitis</italic> genotypes, and also highlighted a possible introgression of <italic>sylvestris</italic> 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 <italic>sylvestris</italic>. The results also highlight that the GrapeReSeq 18K Vitis genotyping chip are suitable for non-<italic>vitis</italic> genotyping and that the range of SNPs heterozygosity in <italic>sylvestris</italic> appears to be up to 6% less and does not overlap the heterozygosity range of <italic>sativa</italic> genotypes.</p>