Genealogy Investigation in over 2,300 Grapevine Cultivars ([i]Vitis vinifera[/i])
Résumé
Since 1997, many studies have been performed based on the inheritance of nuclear microsatellite markers to verify or uncover the parentage of several grapevine cultivars. The aim of the present study was to undertake an extended analysis using a large sample of Vitis vinifera cultivars held in the INRA "Domaine de Vassal" Grape Germplasm Repository (F-34340 Marseillan-Plage, France). We genotyped 5,516 accessions with 20 nuclear SSR markers and checked their identity. The dataset of 2,332 single genotypes identified (without synonyms, clones and mutants) was analyzed using FaMoz software. Parentages showing a LOD score higher than 18 were validated in relation to historical data available. The parentage analysis first permitted the identification of 284 genotypes showing no direct relationship with any other cultivar in the collection. Second, in approx. 1,150 genotypes, only incomplete parentages could be determined due to the absence of complementary parents in the cultivar sample. Last, the full-parentage of approx. 700 genotypes was revealed resulting in i) confirmations of the pedigree as stated by the breeder (180) or in previously published studies (80), ii) partial or complete invalidations of published pedigree (90), or iii) original discoveries (390). Compiling these parentage results improves our knowledge of the genetic constitution of the population of V. vinifera cultivars and the identification of the main genitors involved in varietal assortment evolution and grapevine breeding.