Effects of kaolin particle film on berry histological properties in two table grape cultivars ( V. vinifera L.)

BACKGROUND: Berry skin tissue is important in viticulture and enology due to the storage of phenolic compounds. Changes in the berry metabolism and environmental factors may lead to changes in skin structure and composition. OBJECTIVE: We aimed to determine the effects of kaolin-based particle film (PF) treatment on histological properties of anthocyanin accumulation in the berries of cv. Beauty Seedless and Tekirdag Seedless in two growing seasons. METHODS: PF treatment was applied 3 times beginning from the berry set. Histological structure of berries was observed with optical and transmission electron microscopy. Accumulation of anthocyanins in berry skin cells was determined microscopically and spectrophotometrically. RESULTS: In Beauty Seedless, total anthocyanin content was 512.93–605.90 mgkg –1 in control (C) and it raised to 606.98–666.44 mgkg –1 in PF treated vines. Total anthocyanin content was determined as 72.50–81.43 mgkg –1 (C) and 79.55–84.72 mgkg –1 (PF) in Tekirdag Seedless. 3 cell types were observed regarding anthocyanin localization: cells with no anthocyanin (type 1), cells with vacuolar storage (type 2) and cells with granular storage (type 3). CONCLUSION: We concluded that the PF treatment could be used for increasing anthocyanin concentration with cultivar-specific skin color in Beauty Seedless and Tekirdag Seedless grown in the semi-arid regions.