Ecological and sanitary characteristics of the Eurasian wild grapevine (Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi) in Georgia (Caucasian region)

This paper shows the results of the investigation on some ecological aspects and on the sanitary status of the wild Euroasiatic native grapevine (Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi) in Georgia (South Caucasus). This taxon is seriously endangered by human activities such as forest cleaning and setting fires. Moreover, invasive Vitaceae of the North American origin, imported after phylloxera (Daktulosphaira vitifoliae Fitch) when vineyards were being replanted, increase the risk to lose these spontaneous vines. The survey includes collection of data on the population structure, the plant sex ratio, the main botanical supporters of the vines and the associated flora, the presence of invasive vines of the North American origin and the incidence of phytophagous arthropods and pathogens. The phytosanitary study showed that monophagous eriophyid mites and exotic fungal diseases, such as downy (Plasmopara viticola (Berkeley and Curtis) Berlease and de Toni) and powdery mildews (Erysiphe necator -(Schweinitz) Burrill), cause symptoms on all the observed populations. The absence of symptoms caused by phylloxera, root-knot nematodes and root rot is remarkable. However, the level of detected injuries caused by these parasitic organisms does not seem to be a real problem for the survival of the populations.