Rootstock-scion interaction:5. Effect on the evolution of Cabernet Sauvignon grape ripening

Abstract ?The rootstock effect on grapevine yield components, grape must and wine composition and wine sensory characteristics were evaluated in previous studies. This experiment carried out over five years had the objective to determine the effect of the rootstock on the evolution of variables related to sugar and acidity contents of the juice during grape ripening. The treatments consisted of Cabernet Sauvignon grapevine grafted on rootstocks such as Rupestris du Lot, 101-14 Mgt, 3309 C, 420A Mgt, 5BB K, 161-49 C, SO4, Solferino, 1103 P, 99 R, 110 R, Gravesac, Fercal, Dogridge and Isabel. The berries were sampled during the grape ripening period, on nine datesduring the summer of each year. Taken to the laboratory, they were hand crushed and the juice was centrifuged to separate the solid and liquid phase, where the supernatant was then used for physicochemical analyses. The data were submitted to Principal Component Analysis (PCA) and polynomial regression analysis. The main results show that, at grape maturity, the PCA discriminated mainly the juices of CS/101-14 Mgt, CS/SO4 and CS/Gravesac, which had high density, total soluble solids, total soluble solids/titratable acidity ratio and pH, and CS/Dogridge and CS/Fercal, which had high titratable acidity. The density, total soluble solids, titratable acidity, total soluble solids/titratable acidity ratio increased as grape ripened, but the titratable acidity decreased. However, the increase or decrease rates were lower at the end of the grape ripening cycle according to the variable, and the total soluble solids having the highest increase (116.3%) and the titratable acidity the highest decrease (68.3%). Index terms: Vitis vinifera, viticulture, juice, maturation, composition.Interacao entre porta-enxerto e copa: 5. Efeito na evolucao da maturacao da uva Cabernet SauvignonISSN 0100-2945 DOI: http://dx.doi.org /10.1590/0100-29452019138PropagationResumo - Trabalhos anteriores avaliaram o efeito do porta-enxerto sobre os componentes de producao da videira, da composicao do mosto e do vinho, e das caracteristicas sensoriais do vinho. Neste experimento, conduzido durante cinco anos, o objetivo foi determinar o efeito do porta-enxerto na evolucao de variaveis relacionadas a teores de acucar e acidez do mosto da uva Cabernet Sauvignon enxertada sobre os porta-enxertos Rupestris du Lot, 101-14 Mgt, C 3309, 420A Mgt, K 5BB, C 161-49, SO4, Solferino, P 1103, R 99, R 110, Gravesac, Fercal, Dogridge e Isabel. As bagas foram amostradas na maturacao da uva, em nove datas dos meses de verao de cada ano. No laboratorio, elas foram esmagadas a mao, sendo o mosto centrifugado para separar a fase solida da liquida, e o sobrenadante, utilizado para as analises fisico-quimicas. Os dados foram submetidos a Analise de Componentes Principais (ACP) e a analise de regressao polinomial. Os principais resultados mostram que, na maturidade, a ACP discriminou principalmente os mostos de CS/101-14 Mgt, CS/SO4 e CS/Gravesac ─ que tiveram elevada densidade, solidos soluveis totais, relacao solidos soluveis totais/acidez titulavel e pH ─ e CS/Dogridge e CS/Fercal, que tiveram elevada acidez titulavel. A densidade, os solidos soluveis totais, a acidez titulavel e a relacao solidos soluveis totais/acidez titulavel aumentaram a medida que a uva amadurecia, mas a acidez titulavel diminuiu. No entanto, as taxas de crescimento ou de diminuicao foram menores no final do ciclo de maturacao da uva, de acordo com a variavel, sendo que o maior aumento foi constatado nos solidos soluveis totais (116,3%) e a maior diminuicao, na acidez titulavel (68,3%).Termos para indexacao: Vitis vinifera, viticultura, mosto, maturacao, composicao.