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Emanuelli F.,Research and Innovation Center | Lorenzi S.,Research and Innovation Center | Grzeskowiak L.,Research and Innovation Center | Catalano V.,Research and Innovation Center | And 8 more authors.
BMC Plant Biology

Background: The economic importance of grapevine has driven significant efforts in genomics to accelerate the exploitation of Vitis resources for development of new cultivars. However, although a large number of clonally propagated accessions are maintained in grape germplasm collections worldwide, their use for crop improvement is limited by the scarcity of information on genetic diversity, population structure and proper phenotypic assessment. The identification of representative and manageable subset of accessions would facilitate access to the diversity available in large collections. A genome-wide germplasm characterization using molecular markers can offer reliable tools for adjusting the quality and representativeness of such core samples.Results: We investigated patterns of molecular diversity at 22 common microsatellite loci and 384 single nucleotide polymorphisms (SNPs) in 2273 accessions of domesticated grapevine V. vinifera ssp. sativa, its wild relative V. vinifera ssp. sylvestris, interspecific hybrid cultivars and rootstocks. Despite the large number of putative duplicates and extensive clonal relationships among the accessions, we observed high level of genetic variation. In the total germplasm collection the average genetic diversity, as quantified by the expected heterozygosity, was higher for SSR loci (0.81) than for SNPs (0.34). The analysis of the genetic structure in the grape germplasm collection revealed several levels of stratification. The primary division was between accessions of V. vinifera and non-vinifera, followed by the distinction between wild and domesticated grapevine. Intra-specific subgroups were detected within cultivated grapevine representing different eco-geographic groups. The comparison of a phenological core collection and genetic core collections showed that the latter retained more genetic diversity, while maintaining a similar phenotypic variability.Conclusions: The comprehensive molecular characterization of our grape germplasm collection contributes to the knowledge about levels and distribution of genetic diversity in the existing resources of Vitis and provides insights into genetic subdivision within the European germplasm. Genotypic and phenotypic information compared in this study may efficiently guide further exploration of this diversity for facilitating its practical use. © 2013 Emanuelli et al.; licensee BioMed Central Ltd. Source

Maul E.,JKI Institute for Grapevine Breeding Geilweilerhof | Eibach R.,JKI Institute for Grapevine Breeding Geilweilerhof | Zyprian E.,JKI Institute for Grapevine Breeding Geilweilerhof | Topfer R.,JKI Institute for Grapevine Breeding Geilweilerhof
Vitis - Journal of Grapevine Research

'Heunisch Weiss' (syn. 'Gouais blanc') contributed to a considerable increase of our varietal assortment, including renowned varieties like 'Chardonnay' and 'Riesling Weiss'. Three phenotypic variants of 'Heunisch Weiss' were discovered in the grapevine collection at the JKI Institute for Grapevine Breeding Geilweilerhof: (a) 'Heunisch Dreifarbig' (three coloured 'Heunisch'; VC prime name 'Heunisch Dreifarbig') expressing intense anthocyanin coloration on shoots, inflorescences and leaf petioles before fruit set and even red berry skin at fruit set stage; (b) 'Pekasore' (VC prime name 'Heunisch Rotgestreift'; red striped 'Heunisch';) with rose to red stripes on white berries and (c) the stenospermocarpic 'Aspirant' (VC prime name 'Heunisch Weiss Seedless'). Four cultivars proving to be homonymous in relation to 'Heunisch' were investigated at 24 loci to determine their identity or relatedness to 'Heunisch Weiss', respectively. 'Heunisch Schwarz' turned out to be a 'Heunisch Weiss' offspring. No parent offspring relationship was detected for 'Heunisch Rot', 'Haenisch Rot' = 'Pamid', and 'Heunisch Blau'. Ampelographic description was carried out for some of the accessions to trace back historical evidences. In addition five new 'Heunisch Weiss' offsprings were identified and confirmed by analysing 35 nuclear microsatellite loci. The accession 'Furmint Apiren' turned out to be a seedless bud mutant of the 'Heunisch Weiss' offspring 'Iordan'. Source

Schwander F.,JKI Institute for Grapevine Breeding Geilweilerhof | Eibach R.,JKI Institute for Grapevine Breeding Geilweilerhof | Fechter I.,JKI Institute for Grapevine Breeding Geilweilerhof | Hausmann L.,JKI Institute for Grapevine Breeding Geilweilerhof | And 2 more authors.
Theoretical and Applied Genetics

A population derived from a cross between grapevine breeding strain Gf. Ga-52-42 and cultivar 'Solaris' consisting of 265 F1-individuals was genetically mapped using SSR markers and screened for downy mildew resistance. Quantitative trait locus (QTL) analysis revealed two strong QTLs on linkage groups (LGs) 18 and 09. The locus on LG 18 was found to be identical with the previously described locus Rpv3 and is transmitted by Gf. Ga-52-42. 'Solaris' transmitted the resistance-related locus on LG 09 explaining up to 50% of the phenotypic variation in the population. This downy mildew resistance locus is named Rpv10 for resistance to Plasmopara viticola. Rpv10 was initially introgressed from Vitis amurensis, a wild species of the Asian Vitis gene pool. The one-LOD supported confidence interval of the QTL spans a section of 2.1 centi Morgan (cM) corresponding to 314 kb in the reference genome PN40024 (12x). Eight resistance gene analogues (RGAs) of the NBS-LRR type and additional resistance-linked genes are located in this region of PN40024. The F1 sub-population which contains the Rpv3 as well as the Rpv10 locus showed a significantly higher degree of resistance, indicating additive effects by pyramiding of resistance loci. Possibilities for using the resistance locus Rpv10 in a grapevine breeding programme are discussed. Furthermore, the marker data revealed 'Severnyi' × 'Muscat Ottonel' as the true parentage for the male parent of 'Solaris'. © 2011 Springer-Verlag. Source

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