Integrated Bayesian Approaches Shed Light on the Dissemination Routes of the Eurasian Grapevine Germplasm

Abstract

The domestication and spreading of grapevine as well as the gene flow history had been described in many studies. We used a high-quality 7k SNP dataset of 1,038 Eurasian grape varieties with unique profiles to assess the population genetic diversity, structure, and relatedness, and to infer the most likely migration events. Comparisons of putative scenarios of gene flow throughout Europe from Caucasus helped to fit the more reliable migration routes around the Mediterranean Basin. Approximate Bayesian computation (ABC) approach made possible to provide a response to several questions so far remaining unsolved. Firstly, the assessment of genetic diversity and population structure within a well-covered dataset of ancient Italian varieties suggested the different histories between the Northern and Southern Italian grapevines. Moreover, Italian genotypes were shown to be distinguishable from all the other Eurasian populations for the first time. The entire Eurasian panel confirmed the east-to-west gene flow, highlighting the Greek role as a “bridge” between the Western and Eastern Eurasia. Portuguese germplasm showed a greater proximity to French varieties than the Spanish ones, thus being the main route for gene flow from Iberian Peninsula to Central Europe. Our findings reconciled genetic and archaeological data for one of the most cultivated and fascinating crops in the world.

Dual domestications and origin of traits in grapevine evolution

“…The V. vinifera accessions show a weak isolation-by-distance correlation (Fig. 1C), suggesting a disconnection between the viticultural geographic pattern and the genetic structures in the grapevine ( 20 ). This observation could be due to the extensive exchange of superior cultivars across regions and the subsequent interbreeding throughout history.…”

“…A higher level of cultural exchange characterizes the last stage since the Bronze Age and the trading of superior grapevine cultivars along trade routes. This is especially evident in the plethora of Italian cultivars with three or more genetic ancestries, but unfortunately poses a challenge to disentangle the genealogical history of each grapevine cultivar ( 20 ). Finally, genetically reliable wild grapevines from Central Asia, a region battered by climate change and social instability for the past few millennia, are no longer available to test Vavilov’s theory for a diversity center or a hypothetical turnover of grapevine types caused by Islam conversion in the region.…”

Adaptive and maladaptive introgression in grapevine domestication

“…Grapevine is among the first domesticated crops; it has been widely cultivated for both fruit (table grapes) and wine since antiquity. Historical and archaeological evidence dated the first domestication of grapevines back to 6,000 to 5,800 BC, when ancestors began to collect and propagate sylvestris in regions that may have included the South Caucasus, the northern Fertile Crescent, and the Levant ( 23 – 27 ). After their domestication, grapes were spread throughout the Mediterranean world, leading to the diversification of many locally adapted varieties that are typically clonally propagated ( 28 , 29 ).…”

Grapevine Diversity and Genetic Relationships in Northeast Portugal Old Vineyards

“…According to VIVC data, the varieties 'Hebén', 'Mouratón', 'Montua', 'Tempranillo', 'Palomino', 'Parraleta', 'Grec Rouge', and 'Trousseau Noir' are synonyms of the Portuguese varieties 'Mourisco Branco', 'Tinta Gorda', 'Diagalves', 'Aragonez', 'Malvasia Rei', 'Tinta Caiada', 'Rabigato Francês', and 'Bastardo', respectively (Table 1). Portuguese grapevine germplasm has been recently referred as the main route for gene flow from Iberian Peninsula to Western and Central Europe [43]. The variety 'Hebén' (syn.…”