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Cultivated grapevines (Vitis vinifera) lack resistance to powdery mildew (PM) with few exceptions. Resistance to this pathogen within V. vinifera has been reported in earlier studies and identified as the Ren1 locus in two Central Asian table grape accessions. Other PM-resistant cultivated varieties and accessions of the wild ancestor V. vinifera subsp. sylvestris were soon identified raising questions regarding the origin of the resistance. In this study, F1 breeding populations were developed with a PM susceptible V. vinifera subsp. vinifera breeding line and a PM-resistant subsp. sylvestris accession. Genotyping was carried out with five Ren1 locus linked SSR markers. A PM resistance locus explaining up to 96% of the phenotypic variation was identified in the same genomic position, where the Ren1 locus was previously reported. New SSR marker alleles linked with the resistance locus were identified. We report results of PM resistance in multiple accessions of subsp. sylvestris collected as seed lots or cuttings from five countries in the Caucasus and Central Asia. A total of 20 females from 11 seed lots and 19 males from nine seed lots collected from Georgia, Armenia, and Azerbaijan were resistant to PM. Three male and one female plant collected as cuttings from Afghanistan and Iran were also resistant to PM. Allelic analysis of markers linked with the Ren1 locus in conjunction with disease evaluation data found a high diversity of allelic haplotypes, which are only possible via recombination events occurring over a long time period. Sequence analysis of two alleles of the SSR marker that cosegregates with the resistance found SNPs that were present in the wild progenitor and in cultivated forms. Variable levels of PM resistance among the tested accessions were also observed. These lines of evidence suggest that the powdery mildew fungus may have been present in Asia for a longer time than currently thought, giving the wild progenitor V. vinifera subsp. sylvestris time to coevolve with and develop resistance to this pathogen., We gratefully acknowledge the funding support of the American Vineyard Foundation and the Louise Rossi Endowed Chair research funds. We also gratefully acknowledge the research support of Rong Hu and Nina Romero. C. M.M. was supported by fellowships from CEI Iberus and University— Government of La Rioja during her sabbatical stay. We also wish to thank Dr. John Preece and Bernie Prins of the USDA National Clonal Germplasm Repository.

BACKGROUND: Flavan-3-ol compounds are important secondary metabolites which show high antioxidant activity and are responsible for bitterness and astringency of food products. The aim of this work was to evaluate the potential for selecting grape materials with higher seed flavanol content from a breeding population. The composition and content of flavan-3-ols from 151 genotypes obtained from crossing wine grape varieties was evaluated by UPLC in three consecutive years. RESULTS: Chromatograms of flavan-3-ol compounds showed the same 12 compounds for all samples, but quantitative differences were observed between genotypes as well as parental varieties. The most abundant compounds were (−)-epicatechin and (+)-catechin followed by proanthocyanidins A2 and B2. Progeny showed higher values than the parental genotypes for every detected compound indicating directional transgressive segregation. With these results genotypes with as much as five times more flavanols than their parents could be identified. The year effect was significant; however, high correlations between years for each compound indicated that there is a strong genetic component in the determination of flavanol content. CONCLUSION: Higher contents of seed flavan-3-ols can be obtained by hybridisation, and those genotypes could be used for extracting healthy phytochemicals, adding value to seeds as a sub-product in wine elaboration. © 2016 Society of Chemical Industry.

The increase in vineyard cultivation for the production of grapes or wine is producing a considerable reduction in soil quality. This is a consequence of management practices principally based on frequent tillage and use of herbicides. This type of management disrupts fungal communities which can lead to a reduction in crop production along with an increase in diseases caused by microorganisms that habitually coexist harmlessly in the soil. The objective of this research was the evaluation of the effect of soil management practices and environmental conditions on the soil fungal communities throughout the year in vineyard. For this, the diversity of the fungal communities in soils with different agricultural practices were evaluated. The samplings were carried out in two vineyards, the first was subjected to manage based on tillage where tillage in the alleys and pesticide treatments in the rows were done. The second was managed without tillage allowing colonialization of spontaneous vegetation in the alleys; the rows, as in the other vineyard, which were treated with herbicides. The soil samples were taken every season coinciding with the key growth stages of the vineyard. The samples were processed using the traditional in vitro method. More than 193 different fungal taxa were found; of them 18% were presented in higher abundance than 1% of the total. The majority of these were generalists; however, there were differences in the relative abundance based on the soil treatment (Tr, Ta, NTr, NTa), season and weather. The fungal communities were formed by more than 60% of generalist taxa; the genus Aspergillus was the most frequent. Ten percent of the total taxa were specific to concrete environmental conditions (season and weather) and soil treatment; Penicillium and Trichoderma were the most frequent. The factor most predictive of the composition of communities was attributed to the season in which the soil samples were collected. In terms of soil management, 27% of taxa were specific of management. Significant differences in the fungal compositions of the communities were found. The fungal communities from soils treated with chemical pesticides (rows) contained a substantial number of specific taxa, being 23% of total. These results show that seasonal dynamics of fungal populations in productive vineyards are sensitive to changes caused by soil treatment., This research was supported bythe LIFE programme of the European Commission for the Environment. Project “Demonstration of biodiversity in vitivinicultural landscapes” (BioDiVine) (LIFE09 NAT / FR / 000584)

The main objective of this research was the evaluation of the variability present in a segregating wine grape population derived from a cross between Graciano × Tempranillo, two Spanish varieties, in order to select improved genotypes with potential for producing high-quality wines in a climate change scenario. For that purpose, the phenotypic segregation of 16 agronomic traits related to production and phenology and 11 enological traits related to technical and phenolic maturity was studied in the progeny for three consecutive years. All traits presented transgressive segregation and continuous variation. Year effect was significant for all traits except total, extractable and skin anthocyanins content. However, a high level of genotype consistency for enological traits was revealed by repeatabilities and correlations between years. Significant correlations among traits were observed but most associations were weak. Furthermore, the CAPS (Cleaved Amplified Polymorphic Sequence) marker for the VvmybA genotype was tested to determine whether it would be useful in indirect selection for berry anthocyanins content. The results showed that the number of homozygous and heterozygous genotypes for the functional colour allele adjusted to a 1:1 segregation ratio, and that homozygous genotypes had significantly higher anthocyanins content. Principal component analysis found eight variables that contributed up to 80 % of the phenotypic variability present in the population. Seven groups of hybrids were distinguished based on ripening time, cluster weight, berry weight and anthocyanins content by cluster analysis; and fourteen genotypes were pre-selected for further research. © 2013 Springer Science+Business Media Dordrecht., This research was funded by the Government of La Rioja through the FOMENTA 04/2008 research project. Shiren Song was initially supported by a fellowship from the Chinese Research Council and for the last 3 years by a MAE-AECID fellowship from the Spanish Government.