Identificação e caracterização de castas minoritárias de Vitis vinifera na Região Demarcada do Douro
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2018-04-13
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Uma das vantagens competitivas de Portugal na área da vitivinicultura assenta na existência de um elevado número de castas autóctones e na sua consequente variabilidade genética. Nos últimos anos, as preocupações relativas à problemática das alterações climáticas e suas consequências na fileira vitivinícola têm levado alguns autores a defenderem que uma possível estratégia poderá passar pela exploração do potencial agronómico e enológico de castas minoritárias. Este estudo, realizado no âmbito do projeto INNOVINE&WINE, teve como principais objetivos a identificação molecular de castas minoritárias presentes numa vinha velha da Região Demarcada do Douro, com recurso a seis marcadores microssatélites, a sua caracterização ampelográfica pelo método morfológico de acordo com a Organisation Internationale de la Vigne et du Vin, assim como a avaliação do seu potencial vitícola e enológico através da determinação de vários parâmetros agronómicos e avaliação qualitativa do bago em termos de polifenóis totais, antocianinas, taninos, álcool provável e pH. A identificação de castas com recurso aos seis marcadores moleculares descritos pela OIV resultou em apenas 56 acessos identificados, do total de 98 analisados, tendo correspondido a 19 castas presentes na Coleção Ampelográfica Nacional. Os resultados obtidos para o vigor, número de lançamentos/m2 , produtividade e peso médio do cacho revelaram-se baixos na sua generalidade, mas aceitáveis atendendo à idade da parcela. À exceção das castas Camarate, Cornifesto e Roseira, todas apresentaram Índices de Ravaz baixos o que significa que se encontravam em desequilíbrio vegetativo/produtivo manifestando sinais de senescência. No que diz respeito à riqueza em compostos fenólicos, destacou-se a casta Vinhão que revelou ter simultaneamente o conteúdo mais elevado em taninos, antocianinas e polifenóis totais. De forma conclusiva, verificou-se a existência de um número considerável de castas na parcela de vinha velha estudada que se caracterizou por apresentar um nível qualitativo elevado associado a baixas produtividades. A informação recolhida e compilada no presente estudo constitui um ponto de partida na preservação do património vitícola para a promoção da competitividade e sustentabilidade do sector vitivinícola nacional através da utilização de castas autóctones minoritárias.
Portugal’s enormous grapevine biodiversity translates into one of the country’s major advantages regarding vitiviniculture. In the last few years concerns about climate change and its consequences in the wine sector have led some authors to defend that a possible strategy may consist in exploring the agronomical and enological potential of minor grape varieties. This study, performed under the project INNOVINE&WINE, had the following main objectives: molecular identification of minority grapevine cultivars present in an old vineyard of the Douro Controlled Designation of Origin using microsatellite markers, their ampelographic characterization by means of the morphologic method from the Organisation Internationale de la Vigne et du Vin as well as the assessment of their viticultural and enological potential, both by data concerning agronomic characteristics and grape quality evaluation by analyzing total polyphenols, anthocyanins, tannins, pH and probable alcohol. The identification of grape varieties using the six molecular markers, described by the OIV, resulted in only 56 identified accesses, out of the 98 that were analyzed, corresponding to 19 grape varieties present in the National Ampelographic Collection. The results obtained concerning vine vigor estimation, bunch average weight, shoot number/m2 were low but acceptable considering the vine’s age. With the exception of the Camarate, Cornifesto and Roseira varieties, Ravaz Indexes were also low which means they were in a vegetative/productive imbalance, showing signs of senescence. Regarding phenolic compound richness, Vinhão was found to have the highest content in tannins, anthocyanins and total polyphenols. In conclusion, a considerable number of grape varieties were found in the vineyard in study, which was characterized by a high qualitative level associated with low yields. The information collected in the present study about minor varieties is a starting point to preserve genetic resources not only in homage to cultural heritage but also to diversify the market promoting competitiveness and sustainability of the wine sector.
Portugal’s enormous grapevine biodiversity translates into one of the country’s major advantages regarding vitiviniculture. In the last few years concerns about climate change and its consequences in the wine sector have led some authors to defend that a possible strategy may consist in exploring the agronomical and enological potential of minor grape varieties. This study, performed under the project INNOVINE&WINE, had the following main objectives: molecular identification of minority grapevine cultivars present in an old vineyard of the Douro Controlled Designation of Origin using microsatellite markers, their ampelographic characterization by means of the morphologic method from the Organisation Internationale de la Vigne et du Vin as well as the assessment of their viticultural and enological potential, both by data concerning agronomic characteristics and grape quality evaluation by analyzing total polyphenols, anthocyanins, tannins, pH and probable alcohol. The identification of grape varieties using the six molecular markers, described by the OIV, resulted in only 56 identified accesses, out of the 98 that were analyzed, corresponding to 19 grape varieties present in the National Ampelographic Collection. The results obtained concerning vine vigor estimation, bunch average weight, shoot number/m2 were low but acceptable considering the vine’s age. With the exception of the Camarate, Cornifesto and Roseira varieties, Ravaz Indexes were also low which means they were in a vegetative/productive imbalance, showing signs of senescence. Regarding phenolic compound richness, Vinhão was found to have the highest content in tannins, anthocyanins and total polyphenols. In conclusion, a considerable number of grape varieties were found in the vineyard in study, which was characterized by a high qualitative level associated with low yields. The information collected in the present study about minor varieties is a starting point to preserve genetic resources not only in homage to cultural heritage but also to diversify the market promoting competitiveness and sustainability of the wine sector.
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Vitis vinifera , vinhas velhas , identificação varietal , produtividade , qualidade