engleski

Grape chemical composition evaluation of autochthonous Croatian cultivar cv. Škrlet bijeli clonal candidates

Nowadays is well-known that within cv. Škrlet bijeli population exist certain genetic variability as a consequence of exposure to natural mutation. This is leading to different economic values of genotypes making some of them worthy of further propagation. Experimental collection of autochthonous grapevine cv. Škrlet bijeli clonal candidates on rootstock Kober BB was established in period from year 2001. to year 2004. Besides a variety of economic characteristics that were evaluated, samples of four perspective clonal candidates (ŠK-29, ŠK-33, ŠK-57 and ŠK-69) were collected. The aim of this work was to identify if there are differences in grape quality of four selected clonal candidates. The grape quality was established by nine quality parameters in two harvests (2005 and 2006). Clonal candidates ŠK-29, ŠK-33, i ŠK-69 were virus free while ŠK-57 was positive for GLRV1. Values for grape quality parameters (four clonal candidates) were determined in ranges as folowes: sugar content 17.0 – 22.6 °Brix, total acidity expressed as tartaric acid 6.4 - 8.9 g/L, pH 2.81 - 3.40, tartaric acid 5.4 - 8.8 g/L, malic acid 0.8 - 3.3 g/L, citric acid 0.067 - 0.216 g/L, reducing sugars 172 - 275 g/L, glucose 78.1 - 136.1 g/L and fructose 84.8 - 136.1 g/L. ŠK-29 in comparison to other candidates had higher sugars (º Brix) and pH values, the lowest tartaric acid content and total acidity/reducing sugars ratio. The negative correlation was established for tartaric (-0.44, - 0.78), malic acid (-0.56, -071) in comparison to sugars (°Brix) and pH, respectively. The study confirmed existance of significant variability between clonal candidates and some of them were selected for continuetion of individual clonal selection.

grapevine; Škrlet bijeli; clonal selection; grape; chemical composition

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