Morphological and molecular characterization of grapevine accessions known as Albillo

Twenty-eight accessions identified under the name of Albillo or cited as a synonym of this ancient Spanish grapevine variety were characterized using 43 morphological descriptors, four different isozyme systems (CO, ACPH, GOT, and SOD) and two Amplified Fragment Length Polymorphism (AFLP) primer combinations. Genetic similarity data resulting from these analyses allowed three different groups of Albillo to be distinguished that corresponded with geographical and historical origin of representative varieties: Turruntés, Malvasía de El Bierzo, and the classical Albillo de Madrid, related to the oldest Albillo ampelographical descriptions. In addition, homonyms as well as varieties incorrectly cited as Albillo synonyms were identified. To ensure accurate variety identification, association among historical descriptions based on morphological descriptors and molecular fingerprints was required. Isozymes proved to be useful markers for varietal identification. However, only AFLP allowed distinction among closely related varieties as well as the analysis of intravarietal variation

Garnacha and Garnacha Tintorera: Genetic Relationships and the Origin of Teinturier Varieties Cultivated in Spain

Representative grapevine accessions (Vitis vinifera) cultivated in Spain under the names Garnacha and Garnacha Tintorera, as well as their synonyms, were analyzed to determine genetic diversity and relationships. Both varieties are characterized by high levels of intravarietal morphological variation. Results confirmed the monophyletic origin of the Garnacha variety, which is represented by a main genotype with several phenotypic variants, likely corresponding to somatic mutations. In contrast, Garnacha Tintorera was characterized as a genetically heterogeneous group, which included three different teinturier genotypes. Possible parentage relationships among the teinturier varieties were identified and further confirmed using microsatellites, showing that all are derived from crosses performed in the nineteenth century to improve color intensity of well-known red wine varieties

Molecular genetics of berry colour variation in table grape

The genetics and biochemistry of anthocyanins and flavonol biosynthesis and their role in plant organ pigmentation is well established in model species. However, the genetic basis of colour variation is species specific and understanding this variation is very relevant in many fruit and flower crop species. Among grape cultivars, there is a wide genetic variation for berry colour ranging from yellow-green ("white" cultivars) to dark blue berries. Berry colour results from the synthesis and accumulation of anthocyanins in the berry skin, which in plants is commonly regulated by transcription factors belonging to the MYB and bHLH families. In this work, we aimed to identify the major genetic determinants of berry colour variation in a large collection of table grape cultivars and somatic variants. The genetic analyses of berry colour in a few grape segregating progenies had previously identified a single locus on linkage group 2 responsible for colour variation. Furthermore, somatic variation for berry skin colour in cultivar Italia had been associated with the presence of a Gret1 retrotransposon in the promoter region of VvmybA1, a Myb gene whose expression is associated to skin colouration. The results show that VvmybA1 is the gene underlying the mapped locus controlling berry colour in grape. Additionally, the molecular analyses indicate that genetic and somatic berry colour variation can be associated to molecular variation at VvmybA1 in more than 95% of the analyzed cultivars. Thus, VvmybA1 is a major determinant of berry colour variation in table grape and its instability is the major cause of somatic variation for this trait. © Springer-Verlag 2006