SNP genotyping elucidates the genetic diversity of Magna Graecia grapevine germplasm and its historical origin and dissemination

Abstract

BackgroundMagna Graecia is the ancient name for the modern geopolitical region of South Italy extensively populated by Greek colonizers, shown by archeological and historical evidence to be the oldest wine growing region of Italy, crucial for the spread of specialized viticulture around Mediterranean shores. Here, the genetic diversity of Magna Graecia grape germplasm was assessed and its role in grapevine propagation around the Mediterranean basin was underlined.ResultsA large collection of grapevines from Magna Graecia was compared with germplasm from Georgia to the Iberian Peninsula using the 18 K SNP array. A high level of genetic diversity of the analyzed germplasm was determined; clustering, structure analysis and DAPC (Discriminant Analysis of Principal Components) highlighted the genetic relationships among genotypes from South Italy and the Eastern Mediterranean (Greece). Gene flow from east (Georgia) to west (Iberian Peninsula) was identified throughout the large number of detected admixed samples. Pedigree analysis showed a complex and well-structured network of first degree relationships, where the cultivars from Magna Graecia were mainly involved.ConclusionsThis study provided evidence that Magna Graecia germplasm was shaped by historical events that occurred in the area due to the robust link between South Italian and Greek genotypes, as well as, by the availability of different thermal resources for cultivars growing in such different winegrowing areas. The uniqueness of this ampelographic platform was mainly an outcome of complex natural or human-driven crosses involving elite cultivars.Electronic supplementary materialThe online version of this article (10.1186/s12870-018-1576-y) contains supplementary material, which is available to authorized users.

Marginal Grapevine Germplasm from Apulia (Southern Italy) Represents an Unexplored Source of Genetic Diversity

“…Apulia, stretching into the Mediterranean Sea, has a strategic geographical position, being located on commercial routes of ancient populations such as Phoenicians, Greeks, and Romans. A recent study remarked the central role of Magna Graecia in the spread of grapevine to Western Europe, corroborating the hypothesis that grapevine originated in the Caucasus and then spread to the regions of Southern Italy [39].…”

“…The history of the Mediterranean settlement, trade, and cultural influence supports this hypothesis. Greeks colonized the southern area of Apulia, and evidence of gene flow between Greece and Apulia has been observed [39]. Conversely, there is minor evidence of gene flow in the Gargano, due to a tardive colonization by the Greeks (from the end of V century B.C.).…”

“…In addition, the genetic diversity of the grapevine germplasm from Magna Grecia, the coastal areas of Southern Italy (i.e., Basilicata, Calabria, Campania, Apulia, and Sicily), was investigated using markers spotted onto a 18K SNP array, and provided evidence of gene flow between varieties from Greece and Southern Italy [39]. The identification of divergent loci across germplasm collections may give indications on the genetic differentiation that occurred during the transition from local adapted to modern varieties, as previously investigated in grapevine [40][41][42] and in other Mediterranean crops [43,44].…”

Genetic Relationships Among Portuguese Cultivated and Wild Vitis vinifera L. Germplasm

“…In addition, varieties bearing chlorotypes B, C, and D, found more frequently in Eastern wine varieties (B and D) and table grape varieties (C) (Arroyo-García et al, 2006;Laucou et al, 2018) were also found in Portuguese varieties (Cunha et al, 2009;Cunha et al, 2010;Castro et al, 2013;Cunha et al, 2015) supporting their multiple origins, likely including introductions from the Near East and from the Maghreb. Secondary domestication events have been proposed for grapevine along the Mediterranean basin based on differences in chlorotype frequencies (Grassi et al, 2003;Arroyo-García et al, 2006) or on the increased expected heterozygosity values detected further from the putative center of origin of the species (De Lorenzis et al, 2019).…”

A Transcriptomic Variation Map Provides Insights into The Genetic Basis of Pinus massoniana Evolution and Association of Oleoresin Yield

“…The SNP markers have been used to evaluate diversity within many species, such as Populus trichocarpa [31], Vitis vinifera [32], Ginkgo biloba [33]. SNPs called from transcriptome sequencing is a more efficient strategy for characterizing diversity in non-model or massive-genome species, since the sequences are detected on the coding regions rather than the whole genome.…”