Stress-metabolites phytoalexins-stilbenoids of grape skin Rkatsiteli variety (Vitisvinifera L.) in condition gray mildew

It has been studied Change of phytoalexins - stilbenes of white wine variety Rkatsiteli grape skin in the condition of the disease gray mildew (botrytis cinerea). The samples of health and infected grapes –with 60% gray mildew, were taken in 2018 year during the technical maturity, from the same vineyard planted in eastern Georgia. The vineyard soil belongs to meadow cinnamonic – Calcariccambisols and calcic kastanozems type. Vineyard is 16 years old. Based on the HPLC/MS analysis are established the stilbenoids profiles of healthly and infected skins and has been revealed Stress-metabolite stylbenoids - accumulated as a result of the action of botrytis cinearea. The dominant stress-metabolites Stilbenoides are resveratrol and its derivatives: trans-resveratrol, transpiceid, cis-piceid, trans-piceatannol, trans-ε-viniferin. The variability of these stilbenoids concentrations in the condition of the disease -gray mildew,is different: trans-resveratrol 39.27mg kg1→57.33mg kg-1; trans-piceid 13.72mgkg-1→29.43mgkg-1 ; trans-piceatannol 5.37mg kg1→19.45mg kg-1; trans-ε-viniferin 7.22 mg kg-1→5.13mg kg-1. The stress-metabolite stilbenoids in the conditions of the disease with gray mildew, is a scientific novelty for the grape of Rkatsiteli variety. The results of the research are important for determination the correlation of the vine immunity with the phytoalexins-stilbenoids.