Cold stress often leads to tissue damage and reduces yields in plants and grape which is cultivated in the mountainous areas; is not exception of this concept. Each year, more than 50% of grape products in areas with intense glacial cold winter and late cold of spring are destroyed. In surface of plants, a group of epiphytic bacteria called INA (Ice Nucleation Active) cause the forming of ice cores which intensify the plant sensitivity and increasing the super cooling for 2 to 4 degrees. Among these kinds of bacteria Pseudomonas syringae Van Hall be noted. For example, on the grape leaves, the existence of 108 cell/ml of INA cause frostbiting at -2OC to -4 OC. In this study, from the surface of grape leaves, P. syringae pv.syringae (Pss) strain were isolated by culturing the diluted wash solution of leaves and was detected by dehydrolyze arginine test, oxidase activity, formation of levan polymer in agar medium and having fluorescence of colonies in King B medium. The extracted Pss strain concentration were compared in the ruby (sensitive to cold), white raisins (commercial) and red currant (cold resistant). It was observed that the lowest number of bacteria was in raisins and the highest number of bacteria was in ruby red. In order to reduce frost damage in the country's vineyards provide new solutions is important but the finding scientific and practical solution is difficult without careful attention to the factors causing this problem. Therefore, in this regard for grapes and Vineyard, the relationship between co-existence bacteria and their role in induce or reduce cold stress and frost injury, can be effective in solving of this problem.
