Detection of polymorphism in ancient Tempranillo clones (Vitis vinifera L.) using microsatellite and retrotransposon markers

Tempranillo is one of the most widely cultivated grapevine varieties in Spain. After several years of clone selection, some highly recommended old clones have been identified in terms of both their qualitative and production characteristics. This study was designed to discriminate among 28 ancient clones of the cultivar Tempranillo (Vitis vinifera). DNA samples from clones were analysed using two different molecular markers; microsatellites or simple sequence repeats (SSR) and retrotransposons. The results of this study indicate that one variant genotype was expressed as three alleles. Further analysis revealed the presence of a chimera, in which the third allele was present in the leaf but not root or wood tissue, indicating a functionally double-layered apical meristem. The present research also showed that one of the retrotranposon marker was able to discriminate one grapevine clone (VP1) from the remaining clones

Identification of Vitis vinifera L. Local Cultivars Recovered in Andalusia (Spain) by Using Microsatellite Markers

11 Pàg.In Andalusia (Spain), there are different wine regions that have a great recognized tradition. In these regions, the cultivation of the vine is ancient and there are still vineyards planted with local varieties of Vitis vinifera L. that have not yet been identified. The aim of this research study was to identify 49 accessions of grapevine collected in the districts of four provinces in Andalusia (Spain). All samples were genotyped with 20 microsatellite markers in order to ascertain the identity and analyze the genetic diversity of the collected material. In total, 30 different genotypes were obtained, 22 of them which were identified with named, known varieties by comparison to the Spanish or European microsatellite databases, and eight which are referred to as new genotypes. All loci were polymorphic, and a total of 159 alleles were detected, ranging from 4 to 12 alleles per locus, with an average allele number of 7.95. The overall observed heterozygosity was 0.763 and was slightly higher than expected (0.715), while the gene diversity per locus varied between 0.167 (VVIN73) and 0.967 (VVMD5). A dendrogram representing the genetic similarities among cultivars was depicted using the UPGMA method to investigate their relationships. The eight new genotypes identified in this research work could represent ancient local varieties in danger of extinction. These new cultivars may be used to determine original wines.This research was funded by Ministerio de Ciencia y Tecnología (INIA-Spain), grants number RF2004-00014-00-00, VIN00-036-C6-5X, RF2006-00011-00-00 and RF2007-00017-00-00.Peer reviewe

Epigenetic changes detected in micropropagated hop plants

Micropropagation is a widely used technique in hops (Humulus lupulus L.). However, to the best of our knowledge, the genetic and epigenetic stability of the microplants has never been tested before. In the present study, two hop accessions were established in vitro and micropropagated for 2 years. The genetic and epigenetic stability of the in vitro plants was analyzed with several molecular techniques random amplified DNA polymorphism (RAPD), retrotransposon microsatellite amplified polymorphism (REMAP), and methylation-sensitive amplification polymorphism (MSAP). No genetic variation among control and treated plants was found, even after 12 cycles of micropropagation. Epigenetic variation was detected, first, when field and in vitro samples were compared. Nearly a 30% of the detected fragments presented the same pattern of alterations in all the vitroplants. Second, lower levels of epigenetic variation were detected among plants from the different subcultures. Part of this detected variation seemed to be accumulated along the 12 sequential subcultures tested. © 2009 Elsevier GmbH. All rights reserved

Assessment of genetic and epigenetic variation in hop plants regenerated from sequential subcultures of organogenic calli

Organogenic calli induced from internodal segments were subcultured three times. Regenerated plants obtained from each subculture were analysed by molecular methods. No major genetic rearrangements were detected in the callus-derived plants since none of the amplified fragment-length polymorphism (AFLP) loci were found to be polymorphic. However, epigenetic changes due to a demethylation process were detected by methylation-sensitive amplified polymorphism (MSAP) technique. The results allowed inference of the possible relationship among the plants derived from different calli subcultures and the in vitro control. The plants recovered from the first and second callus subcultures clustered with the in vitro control pools in the phenogram while the regenerants from the third callus subculture showed the highest genetic distance with the controls. This is the first study reporting data about the genetic stability of callus-derived Humulus lupulus L. plants

Berry color variation in grapevine as a source of diversity

Even though it is one of the oldest perennial domesticated fruit crops in the world, grapevine (Vitis vinifera L.) cultivation today is the result of both conventional breeding practices (i.e. hybridizations adopted during the last century) and vegetative propagation. Human-assisted asexual propagation has allowed the maintenance of desired traits but has largely impacted the frequency of spontaneous somatic mutations observed in the field. Consequently, many grapevine fruit attributes to date have been artificially selected, including: fruit yield, compactness, size and composition, the latter being greatly diversified in the pursuit of altering berry skin coloration. The present review provides an overview of various aspects related to grapevine diversity, with a special emphasis on grape berry skin color variation and will discuss the current knowledge of how grape skin color variation is affected by the synthesis of phenolic compounds, particularly anthocyanins and their underlying genetic factors. We hope this knowledge will be useful in supporting the importance of the berry color trait diversity in cultivated grapevines, which is used as basis for selection during breeding programs because of its application for vine growers, winemakers and consumers

Anthocyanin composition of several wild grape accessions

This study investigated the anthocyanin composition of 21 mostly Spanish wild grapevine accessions preserved at El Encín Germoplasm Bank and selected in consideration of observed ampelographic differences and molecular characterization. Sampling was carried out in 2006, 2007, and 2008. After extraction from grape skins, total anthocyanins was determined by spectrophotometry and the anthocyanin fingerprint of grapes, based on 15 anthocyanin variables, was determined by HPLC. Total anthocyanin concentration was similar to that found in winegrape cultivars. The accessions studied showed considerable variability in their anthocyanin fingerprints and it was possible to distinguish several groups, similar to previous reports on the anthocyanin fingerprint of winegrapes. The anthocyanin composition of wild grapevine accessions was similar to that of cultivated grapes. Nevertheless, the presence of wild accessions with anthocyanin fingerprints uncommon or nonexistent in Spanish cultivated varieties suggests that the genetic variability related to anthocyanins in Spanish wild grapevine populations may be higher than that of cultivated varieties commonly considered of Spanish origin. © 2010 by the American Society for Enology and Viticulture. All rights reserved

Genetics and expression of anthocyanin pathway genes in the major skin-pigmented Portuguese cultivar ‘Vinhão’ developing berries

‘Vinhão’ is an autochthonous Portuguese cultivar with an intense black-bluish skin color, highly appreciated due to this feature. This study aimed to give the first insights into the genetic background that may be responsible for the skin color properties of cv. ‘Vinhão’. For this purpose, the allelic composition of MYBA1 and MYBA2 genes was investigated, along with quantification of the expression levels of structural and regulatory genes involved in the anthocyanin biosynthetic pathway via qRT-PCR. The molecular characterization of MYBA1 and MYBA2 loci revealed that cv. ‘Vinhão’ is homozygous for the functional allele in both genes, corresponding to the most ancestral haplotype, which is consistent with the high colored phenotype that characterizes this cultivar. There were no differences in the DNA sequence of the MYBA1 promoter region between cv. ‘Vinhão’ and the grapevine reference genome Pinot Noir. The expression patterns of genes playing key functional roles in anthocyanin biosynthesis was analyzed in four developmental stages. The dynamics occurring throughout grape berry development revealed the involvement of these genes in the progression of key development events, mainly from veraison to mature berries. These findings provide the first molecular characterization focused on the skin color feature of cv. ‘Vinhão’ to improve our understanding of the genetics behind its intense skin pigmentation

Molecular characterization of berry skin color reversion on grape somatic variants

[BACKGROUND], During grapevine domestication somatic variation has been used as a source of diversity for clonal selection. [OBJECTIVE], This work provides additional information on the molecular mechanisms responsible for berry skin color reversion on a subset of somatic variants for berry skin color never investigated before. [METHODS], The berry color locus and its surrounding genomic regionwere genetically characterized through a layer-specific approach, which has already been proven to be a successful method to decipher the molecular mechanisms responsible for color reversions on somatic variants. [RESULTS], Deletions of different extent and positions were detected among less-pigmented/unpigmented variants derived from a pigmented wild-type. These deletions affected only the inner cell layer in the less pigmented variants and both cell layers in the unpigmented variants. Regarding the pigmented variants derived from an unpigmented wild-type, only one group was distinguished by the Gret1 retrotransposon partial excision from the VvMybA1 promoter. Moreover, within this latter group, VvMybA2 showed an important role regarding the phenotypic variation, through the recovery of the functional G allele. [CONCLUSIONS], This investigation focused on the berry color locus using somatic variants for berry skin color, promotes a better understanding of the evolutionary events behind their origin and variability, opening an opportunity for their use in the genetic improvement of varieties