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M. Dolores Loureiro, M. Carmen Martínez, Jean-Michel Boursiquot and Patrice This

`Albariño' (Vitis vinifera L.) is an important grape cultivar in Spain, morphologically diverse but subject to much misnaming. The objectives of the present work were to correct some of the more common misnamings concerning `Albariño' and to evaluate the genetic variability within this cultivar by analyzing DNA polymorphisms using randomly amplified polymorphic DNA (RAPD) markers and microsatellite techniques. Several accessions of `Albariño' (16 accessions from Misión Biológica de Galicia, one accession from El Encin, one accession from Rancho de la Merced), related cultivars (`Alvarinho', `Caíño blanco', `Cainho branco', `Loureiro'), and cultivars presumably identical to misnomers (`Savagnin blanc' and `Gewürztraminer') were analyzed using 20 RAPD markers and six microsatellite loci. Both techniques revealed polymorphism among `Albariño', `Caíño blanco', `Albariño' from Rancho de la Merced and `Loureiro'. No polymorphism was detected among the 16 `Albariño' accessions from Galicia, the `Albariño' accession from El Encin and `Alvarinho', nor among the `Albariño' accession from Rancho de la Merced, `Savagnin blanc' and `Gewürztraminer', nor between `Caíño blanco' and `Cainho branco'. These results enabled us to clarify the main misnomers concerning these cultivars. The absence of polymorphism among the true `Albariño' accessions did not allow the detection of any clonal variation. The suitability of both techniques for defining the cultivar level for grapevine is discussed.

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Summaira Riaz, Keith E. Garrison, Gerald S. Dangl, Jean-Michel Boursiquot and Carole P. Meredith

In total, 25 clones of Vitis vinifera `Pinot noir' and 22 clones of `Chardonnay' were analyzed with 100 microsatellite markers, selected from an initial screening of 228 markers. Of the 100 markers, 17 detected polymorphism within one or both of the cultivars. In `Pinot noir', 15 polymorphic markers detected 15 different genotypes, uniquely distinguished 12 clones out of the 25 and separated the remaining 13 clones into 3 groups. In `Chardonnay', 9 polymorphic markers detected 9 genotypes and uniquely distinguished 6 clones out of the 22. The remaining 16 clones were separated into 3 groups. For markers that were polymorphic in `Pinot noir' and `Chardonnay', none of the variant alleles were common to both cultivars. It is inferred from this result that the natural cross that produced `Chardonnay' probably occurred when `Pinot' was still relatively young. Many of the variant genotypes were expressed as three alleles. Further analysis revealed the presence of chimeras in which the third allele was present in leaf but not root or wood tissues, confirming that the grape apical meristem is functionally two-layered. Some clones that share the same microsatellite genotype are documented to have originated in the same locality, suggesting that the origins of undocumented clones may be traced by comparing their microsatellite genotypes with those of well-documented clones. Because clones of `Pinot noir' and `Chardonnay' are often visually indistinguishable, microsatellite genotyping may also be useful to detect identification errors in collections and nurseries.

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Manuel Di Vecchi Staraz, Roberto Bandinelli, Maurizio Boselli, Patrice This, Jean-Michel Boursiquot, Valérie Laucou, Thierry Lacombe and Didier Varès

Genetic structuring and parentage analysis were performed on a very large database comprising 2786 unique multilocus genotypes [20 nuclear simple sequence repeats (nSSRs)] of Vitis vinifera L. ssp. sativa (DC.) Hegi with a special focus on Tuscan cultivars to reveal the parentage and history of the cultivar Sangiovese, the most important cultivar of Italy. For this cultivar, the authors also analyzed clones and synonyms, investigating its genetic origin and intracultivar diversity. Known synonyms of ‘Sangiovese’ were confirmed and new ones were revealed with cultivars outside Tuscany. Some synonyms were invalidated, and unexpected homonyms were identified. The absence of true intracultivar variability leads to the rejection of a polyclonal origin for ‘Sangiovese’. The existence of an Italian genetic pool composed of ancient cultivars including Sangiovese was demonstrated by analyzing the entire set of 2786 cultivars. Ten individuals compose the kin group of ‘Sangiovese’, including two offspring: ‘Ciliegiolo’ and ‘Catarratto bianco faux’. Despite the large presence and long history of ‘Sangiovese’ in the Tyrrenian area, its kin group is unexpectedly composed of a majority of ancient cultivars that are largely diffused in far southern Italy, which leads to the hypothesis of a Sicilian origin for ‘Sangiovese’. Analysis of the Tuscan pool revealed large kin groups for cultivars Mammolo and Garganega, demonstrating their contribution to the genetic diversification in the Tyrrenian area. This work contributes to the understanding of grapevine diversification, evolution, and history in Italy and Europe.