Genetic diversity analysis of cultivated and wild grapevine (Vitis vinifera L.) accessions around the Mediterranean basin and Central Asia.

BMC Plant Biol. 2018 Jun 27;18(1):137. doi: 10.1186/s12870-018-1351-0. Riaz S1, De Lorenzis G2, Velasco D3, Koehmstedt A4, Maghradze D5, Bobokashvili Z6, Musayev M6, Zdunic G7, Laucou V8, Andrew Walker M1, Failla O2, Preece JE4, Aradhya M4, Arroyo-Garcia R9. Author information 1 Department of Viticulture and Enology, University of California, Davis, CA, 95616, USA. 2 Department of Agricultural and Environmental Sciences, via Celoria 2, 20133, Milan, Italy. 3 Plant Sciences Department, UC Davis, Davis, CA, 95616, USA. 4 USDA-ARS, National Clonal Germplasm Repository, University of California, Davis, CA, 95616, USA. 5 Institute of Horticulture, Viticulture, and Oenology, Agricultural University of Georgia, Tbilisi, Georgia. 6 Department of Fruit Crops, Genetic Resources Institute, Azerbaijan National Academy of Sciences, AZ1106, Baku, Azerbaijan. 7 Institute for Adriatic Crops and Karst Reclimation, Split, Croatia. 8 INRA, UMR AGAP, F-34060, Montpellier, France. 9 Dpto. Biotecnología, CBGP-INIA, Campus de Montegancedo, Autovía M40 km 38, Pozuelo de Alarcón, 28223, Madrid, Spain. rarroyo@inia.es. Abstract BACKGROUND: The mountainous region between the Caucasus and China is considered to be the center of domestication for grapevine. Despite the importance of Central Asia in the history of grape growing, information about the extent and distribution of grape genetic variation in this region is limited in comparison to wild and cultivated grapevines from around the Mediterranean basin. The principal goal of this work was to survey the genetic diversity and relationships among wild and cultivated grape germplasm from the Caucasus, Central Asia, and the Mediterranean basin collectively to understand gene flow, possible domestication events and adaptive introgression. RESULTS: A total of 1378 wild and cultivated grapevines collected around the Mediterranean basin and from Central Asia were tested with a set of 20 nuclear SSR markers. Genetic data were analyzed (Cluster analysis, Principal Coordinate Analysis and STRUCTURE) to identify groups, and the results were validated by Nei's genetic distance, pairwise FST analysis and assignment tests. All of these analyses identified three genetic groups: G1, wild accessions from Croatia, France, Italy and Spain; G2, wild accessions from Armenia, Azerbaijan and Georgia; and G3, cultivars from Spain, France, Italy, Georgia, Iran, Pakistan and Turkmenistan, which included a small group of wild accessions from Georgia and Croatia. Wild accessions from Georgia clustered with cultivated grape from the same area (proles pontica), but also with Western Europe (proles occidentalis), supporting Georgia as the ancient center of grapevine domestication. In addition, cluster analysis indicated that Western European wild grapes grouped with cultivated grapes from the same area, suggesting that the cultivated proles occidentalis contributed more to the early development of wine grapes than the wild vines from Eastern Europe. CONCLUSIONS: The analysis of genetic relationships among the tested genotypes provided evidence of genetic relationships between wild and cultivated accessions in the Mediterranean basin and Central Asia. The genetic structure indicated a considerable amount of gene flow, which limited the differentiation between the two subspecies. The results also indicated that grapes with mixed ancestry occur in the regions where wild grapevines were domesticated. KEYWORDS: Domestication; Genetic structure; Microsatellite; V. vinifera subsp. sativa; V. vinifera subsp. sylvestris PMID: 29945553 DOI: 10.1186/s12870-018-1351-0 Free full text