The use of rootstocks is gaining importance in Indian viticulture due to problems associated with abiotic stresses, such as drought and salinity, and also to improve scion characteristics. Thompson Seedless is the only commercial cultivar grown for both fresh consumption and raisin making. Dog Ridge was the only popular rootstock used by grape growers prior to late 1990s. But this rootstock was known to induce more vigour in scions, resulting in reduced bud fruitfulness and thereby fruit yield. To identify alternate rootstocks suitable for Thompson Seedless, a study was initiated in the National Research Centre for Grapes, Pune, India during the year 2001. Five rootstocks with own rooted vines were evaluated in this study. During the initial years, Thompson Seedless grafted on Dog Ridge produced the highest yield, with good quality fruit. Over the years we could observe uneven bud sprouting, gaps on the cordon due to dead wood formation, and reduced yield in vines grafted on Dog Ridge rootstocks. In contrast, Thompson Seedless grafted on 110R performed well in terms of moderate vigour, increased fruitfulness and consistently higher yield. Dog Ridge and St. George produced a lower yield, owing to increased vigour measured in terms of pruning weight, total shoot length and cane diameter. Rootstocks 110R, 1103P and 99R are also known to increase water-use efficiency during critical growth stages of fruit bud differentiation and full bloom. No significant influence of rootstocks was observed for most of the fruit composition parameters. Larger and bolder berries were produced on Dog ridge and 110R rootstock, while they were the smallest on own rooted vines.

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The influence of 10 different rootstocks was investigated for evaluating the most suitable rootstock for table grape cultivar Fantasy Seedless. The growth performance, photosynthesis, biochemical composition, and primary nutrients' status of the scion after grafting were investigated in 'Fantasy Seedless' grafted on 10 different rootstocks. The studies on vegetative parameters revealed that the rootstock influences the vegetative growth thereby increasing the photosynthesis of a vine. The rootstock influenced the changes in biochemical constituents in the grafted vine thus helping the vine to store enough food material. The grafted vines exhibited variations in primary nutrients status highlighting the scope for selection of better rootstock for sustainable nutrition management.

Grapes are well known for their high content of phenolic compounds. Polyphenols are classified into flavonoids and non-flavonoids by their primary chemical structures of hydroxybenzene. Flavonoids mainly consist of anthocyanins, flavonoids, and flavonols whereas nonflavonoids include hydroxycinnamic and hydroxybenzoic acids. In the present study, sixteen phenolic compounds from ten red and nine white grape wine varieties were quantified using high-performance liquid chromatography. Gallic acid, Vanillic acid, Rutin hydrate, Ellagic acid, Chlorogenic acid, Sorbic acid, Catechin hydrate, Epicatechin, p-coumaric acid, Quercetin, Myricetin, Kaempferol, Piceatannol, and Resveratrol were major compounds found in red wine grapes. Among the varieties, Petit Verdot, Cabernet Franc showed maximum quantitative phenolics, whereas Cabernet Sauvignon, Niellucio, Cinsaut, and Syrah showed least quantitative phenolics in grape berries. Phenolic profile of white wine grapes showed lower concentration of phenolics than that of red wine grapes. The variety Gros Meseng showed maximum phenolics followed by Sauvignon, while the variety Colombard and Chenin Blanc showed least phenolics.

The variations in growth, powdery mildew and anthracnose incidence and biochemical changes in Thompson Seedless grapevines grafted onto Dog Ridge and 110-R rootstocks in comparison to the own rooted grape vines was investigated. Bud sprouting after pruning was achieved earlier in case of own-rooted vines. However, the vine growth pattern studied in terms of the shoot length, inter nodal length, shoot diameter and leaf area was highest in case of vines grafted onto Dog Ridge. Foliar powdery mildew and anthracnose incidence was highest in vines grafted onto Dog Ridge and own-rooted vines, respectively. The disease incidence was recorded least in vines grafted onto 110-R. The biochemical analysis was also influenced by the rootstocks. The leaves of vines grafted onto Dog Ridge recorded the highest reducing sugars and protein contents and the least total sugars and phenolic contents. The vines grafted onto 110-R topped in total phenolic contents and other phenolic derivatives.