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

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

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 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

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

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 \u2013 7 accessions, high - 13, medium - 15, low \u2013 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