28 research outputs found
Screening of Georgian grapevine germplasm for susceptibility to downy mildew (Plasmopara viticola)
Downy mildew, caused by the obligate biotrophic parasite Plasmopara viticola, is one of the most serious grapevine diseases with worldwide distribution. Resistant grapevines can be used to reduce damages caused by the pathogen, recently different levels of susceptibility to P. viticola were detected in some Georgian autochthonous varieties. The aim of the present work was to classify additional Georgian autochthonous varieties into different groups according to their susceptibility to the downy mildew agent in the framework of COST Action FA1003 "East-West Collaboration for Grapevine Diversity Exploration and Mobilization of Adaptive Traits for Breeding". The leaf disk assay defined by the OIV 452-1 protocol was used for screening 61 native varieties of Georgia. Screened varieties showed different degree of resistance: very high – 7 accessions, high - 13, medium - 15, low – 23, and very low - 3 accessions. The results suggest that further resistant genotypes are likely to be found within more than 500 Georgian grapevine cultivars
Evaluation of eno-carpological traits in Georgian grapevine varieties from Skra germplasm repository
Eno-carpological traits were evaluated in twenty one colored and fifteen white Georgian autochthonous grapevine varieties grown in the Skra Germplasm Repository, during two years (2012 and 2013). Mostly of the studied accessions were minor varieties originated from various Georgian provinces. The spectrophotometric method proposed in the framework of the COST action FA1003 has been adopted for total anthocyanin and polyphenol analyses in skin and seed extracts. The obtained results showed that the content of phenolic compounds as well as other eno-carpological parameters varies greatly according to the variety. In general, the total phenol contents ranged from 546.7 to 2818.4 mg∙kg-1 of grape, and anthocyanins varied from 49.5 to 2826.6 mg∙kg-1 of grape. The highest content of total phenolics and total anthocyanins was found in the variety 'Saperavi Budeshuriseburi'
Sanitary status of the Eurasian wild grapevine in the South Caucasian region
A prospecting on the sanitary status of the aerial organs and roots of the Eurasian wild grapevine, Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi, was carried out on 14 natural populations situated along river bank forests, floodplains and colluvial positions in Georgia (Marneuli, Mtskheta and Gori districts, Gardabani Protected area and Lagodekhi Reserve), Armenia (Akhtala and Tavoush regions) and Azerbaijan (Quba region). These zones are included within the Holarctic kingdom, Eurosiberian region, and to the Caucasian, Euxine and Hyrcanian biogeographical provinces. The results of study indicate that roots are free of symptoms caused by phylloxera, rot fungi and root-knot nematodes. Symptoms caused by the erineum strain of Colomerus vitis (Pagenstecher) and Calepitrimerus vitis (Nalepa) (Acari, Eriophyidae) are frequent. On the other hand, damages caused by powdery and downy mildews, Erysiphe necator (Schweinitz) Burrill and Plasmopara viticola (Berkeley and Curtis) Berlease and de Toni), respectively, show an irregular intensity on leaves belonging to different vines from each location
Study of genetic variability in Vitis vinifera L. germplasm by high-throughput Vitis18kSNP array: the case of Georgian genetic resources
Background
Georgia, in the Caucasian region, is considered the first domestication centre of grapevine. This country is characterized by high morphological variability of cultivated (Vitis vinifera L. subsp. sativa (DC.) Hegi) and wild (Vitis vinifera L. subsp. sylvestris (Gmel.) Hegi) compartments. The main objective of this study was to investigate the level of genetic diversity obtained by the novel custom Vitis18kSNP array, in order to analyse 71 grapevine accessions representative of wild and cultivated Georgian germplasms.
Results
The number of loci successfully amplified was 15,317 out of 18,775 SNP and 79 % of loci resulted polymorphic. Sixty-eight unique profiles were identified, 42 for the sativa and 26 for the sylvestris compartment. Cluster analysis highlighted two main groups, one for cultivars and another for wild individuals, while a genetic structure according to accession taxonomic status and cultivar geographical origin was revealed by multivariate analysis, differentiating clearly the genotypes into 3 main groups, two groups including cultivars and one for wild individuals, even though a considerable overlapping area was observed.
Conclusions
Pattern of genetic diversity structure presented an additional proof that grapevine domestication events took place in the Caucasian region contributing to the crop evolution. Our results demonstrated a moderate differentiation between sativa and sylvestris compartments, even though a connection between several samples of both subspecies may be assumed for the occurrence of cross hybridization events among native wild populations and the cultivated accessions. Nevertheless, first degree relationships have not been discovered between wild and cultivated individuals
Molecular investigation of Caucasian and Eastern European grapevine cultivars (V. vinifera L.) by microsatellites
Grapevine (V. vinifera L.) is one of the most widely cultivated species of agricultural interest. The domestication of wild grapes starting in the Neolithic Age, took place in the Near East area. The aim of this study was the genotyping of germplasm coming from Armenia, Azerbaijan, Georgia and Moldova by SSR markers in order to investigate the genetic relationships among samples along the East-to-West dissemination route of grapevine after the domestication. Based on the descriptive statistics Azerbaijani samples appeared having the highest genetic diversity. PCoA and STRUCTURE analysis revealed three groups: i) Central European group; ii) a group reuniting cultivars coming from Armenia, Georgia and Moldova; iii) the group of Azerbaijani cultivars (94%). The analysis of genetic relationships in our dataset provided evidence of connection among cultivars included in the proles pontica and proles orientalis and geographical origin and human uses as well
Support trees and shrubs for the Eurasian wild grapevine in Southern Caucasus
A prospecting of habitats and mechanical support host species for the climber Eurasian wild grapevine, Vitis vinifera L. subsp. sylvestris (Gmelin) Hegi, was carried out on 13 natural populations situated along river bank forests, floodplains and colluvial positions in Georgia (Marneuli, Mtskheta and Gori districts, Gardabani Protected area and Lagodekhi Reserve), Armenia (Akhtala and Tavoush regions) and Azerbaijan (Quba region) during survey of 2013. The research demonstrated that Eurasian wild grapevine (Vitis vinifera subsp. sylvestris) is found in Southern Caucasus in a wide variety of habitats always linked to water availability. Punica granatum trees are the commonest mechanical support for wild grapevine in the South Caucasus and Hedera helix often shares the same support trees. However we documented wild grapevines climbing on other 24 different species of trees and large shrubs and, further, 32 associated species. We determined, four different clusters of localities using Structure software and the Weighted Neighbor Joining tree. These clusters are characterized by specific mechanical support and accompanying species. Other vines competing for host with Eurasian wild grapevine belong to the genera Clematis, Hedera, Humulus, Smilax and Vitis ssp
Description of the Vitis vinifera L. phenotypic variability in eno-carpological traits by a Euro-Asiatic collaborative network among ampelographic collections
The grapevine intra-specific variability captured an increasing interest during the last decades, as demonstrated by the number of recently funded European projects focused on the grapevine biodiversity preservation. However, nowadays, crop plants are mainly characterized by genotyping methods. The present work summarizes the phenotype data collected among 20 ampelographic collections spread in 15 countries, covering mostly of the viticultural areas in the Euro-Asiatic range: from Portugal to Armenia and from Cyprus to Luxembourg. Together with agro-climatic characterization of the experimental site, in two years, about 2400 accessions were described, following a common experimental protocol mainly focused on the carpological and oenological traits, obtaining a general overview of the distribution of the considered phenotypic traits in the cultivated Vitis vinifera species. The most replicated cultivars were selected and, for the subset of these reference cultivars, their behavior in the different environmental conditions over sites and years was described by ANOVA methods
Description of the vitis vinifera L. Phenotypic variability in eno-carpological traits by a Euro-Asiatic collaborative network among ampelographic collections
The grapevine intra-specific variability captured an increasing interest during the last decades, as demonstrated by the number of recently funded European projects focused on the grapevine biodiversity preservation. However, nowadays, crop plants are mainly characterized by genotyping methods. The present work summarizes the phenotype data collected among 20 ampelographic collections spread over 15 countries, covering most of the viticultural areas in the Euro-Asiatic region: from Portugal to Armenia and from Cyprus to Luxembourg. Together with agro-climatic characterization of the experimental site, over two years about 2,400 accessions were described. A common experimental protocol mainly focused on the carpological and oe-nological traits was followed, obtaining a general overview of the distribution of the considered phenotypic traits in the cultivated Vitis vinifera species. The most replicated cultivars were selected and, for the subset of these reference cultivars, their behavior in the different environmental conditions over sites and years was described by ANOVA methods