A B S T R A C TThe objective of this work was to evaluate the yield components and physicochemical characteristics of bunches and berries of new grape varieties for juice elaboration, which were 'Isabel Precoce' (Vitis labrusca L.) and the hybrids 'BRS Carmem', 'BRS Cora' and IAC 138-22 'Máximo' grown onto 'IAC 572' and 'IAC 766' rootstocks under tropical conditions. The yield components (number of bunches and yield per vine, as well as productivity) and the physicochemical characteristics of the bunches and berries of the eight scion-rootstock combinations were evaluated in three seasons. All data were subjected to analysis of variance and principal components analysis. The varieties 'Isabel Precoce', 'BRS Cora' and IAC 138 22 'Máximo' produced high fruit yield, with the number of bunches and yield per vine similar to one another and superior to those of 'BRS Carmem'. Significant differences occurred among varieties in the physicochemical grape characteristics. 'Isabel Precoce' and 'BRS Carmem' grapes had balanced levels of sugar and acid content, and 'BRS Cora' presented large bunches and berries, reaching high soluble solids content despite the high acidity. IAC 138-22 'Máximo' grape also had large bunches but small berries and limited potential in the accumulation of sugars. The 'IAC 766' rootstock resulted in the best performance across all four varieties evaluated, showing maximum results in terms of fruit yield and physicochemical quality attributes of grapes.

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RESUMO -Objetivou-se avaliar a influência dos porta-enxertos 'IAC 766', 'IAC 572', 'IAC 313' e 'IAC 571-6' na extração de nutrientes pelos ramos removidos na poda e pela colheita dos cachos da videira 'Niagara Rosada', cultivada em Votuporanga, no Estado de São Paulo, Brasil. Realizou-se a poda de produção em 18-08-2009, em que avaliaram a massa fresca e a massa seca dos ramos, visando a estimar o acúmulo de biomassa pelos ramos da videira. Na colheita, estimou-se a produtividade pela pesagem dos cachos/planta e do número de plantas/ha. As amostras de ramos e cachos foram submetidas à análise química de nutrientes e, baseado no acúmulo de massa seca dos ramos e na produtividade, estimou-se a extração de nutrientes. Obteve-se, com o porta-enxerto 'IAC 572', maior extração de nutrientes pelos ramos. Referente aos cachos, obteve-se maior extração de nutrientes com o porta-enxerto 'IAC 766'. A extração diferencial de nutrientes pela 'Niagara Rosada', em função do porta-enxerto, pode servir como base para a adubação dos vinhedos. Termos para indexação: Vitis, nutrição mineral, porta-enxerto, extração. NUTRIENTS EXTRACTION BY VINE 'NIAGARA ROSADA' GRAFTED ON DIFFERENT ROOTSTOCKSABSTRACT -The objective was to evaluate the influence of rootstocks 'IAC 766', 'IAC 572', 'IAC 313' and 'IAC 571-6' on nutrient extraction by the branches removed by pruning, and bunches harvesting of 'Niagara Rosada', grown in Votuporanga, São Paulo state, Brazil. Pruning was done in 08/18/2009, when fresh and dry mass of branches were evaluated, aiming to estimate the biomass accumulation in the branches of the vine. At the harvest, the yield was estimated by the weight of clusters/plant and the number of plants/ha. Samples of branches and clusters were submitted to chemical analyses of nutrients and, based on the accumulation of dry mass of branches and the yield the extraction of nutrients was estimated. We observed for rootstock 'IAC 572' the higher extraction of nutrients by the branches. Referring to the extraction of nutrients by the clusters, we observed a higher extraction for the 'IAC 766'. The differential extraction of nutrients by 'Niagara Rosada' depending on the rootstock, can serve as a basis for the fertilization of the vineyards.

The management of germplasm banks is complex, especially when many accessions are involved. Microsatellite markers are an efficient tool for assessing the genetic diversity of germplasm collections, optimizing their use in breeding programs. This study genetically characterizes a large collection of 410 grapevine accessions maintained at the Agronomic Institute of Campinas (IAC) (Brazil). The accessions were genotyped with 17 highly polymorphic microsatellite markers. Genetic data were analyzed to determine the genetic structure of the germplasm, quantify its allelic diversity, suggest the composition of a core collection, and discover cases of synonymy, duplication, and misnaming. A total of 304 alleles were obtained, and 334 unique genotypes were identified. The molecular profiles of 145 accessions were confirmed according to the literature and databases, and the molecular profiles of more than 100 genotypes were reported for the first time. The analysis of the genetic structure revealed different levels of stratification. The primary division was between accessions related to Vitis vinifera and V. labrusca, followed by their separation from wild grapevine. A core collection of 120 genotypes captured 100% of all detected alleles. The accessions selected for the core collection may be used in future phenotyping efforts, in genome association studies, and for conservation purposes. Genetic divergence among accessions has practical applications in grape breeding programs, as the choice of relatively divergent parents will maximize the frequency of progeny with superior characteristics. Together, our results can enhance the management of grapevine germplasm and guide the efficient exploitation of genetic diversity to facilitate the development of new grape cultivars for fresh fruits, wine, and rootstock.

The objective of this work was to evaluate the influence of rootstocks and pruning times on yield and on nutrient content and extraction by pruned branches and harvested bunches of 'Niagara Rosada' grapevine in subtropical climate. The rootstocks 'IAC 766', 'IAC 572', 'IAC 313', 'IAC 571-6', and '106-8 Mgt' were evaluated. Treatments consisted of a combination between five rootstocks and three pruning times. At pruning, fresh and dry matter mass of branches were evaluated to estimate biomass accumulation. At harvest, yield was estimated by weighing of bunches per plant. Branches and bunches were sampled at pruning and at harvest, respectively, for nutrient content analysis. Nutrient content and dry matter mass of branches and bunches were used to estimate total nutrient extraction. 'Niagara Rosada' grapevine grafted onto the 'IAC 572' rootstock had the highest yield and dry matter mass of bunches, which were significantly different from the ones observed in 'Niagara Rosada'/'IAC 313'. 'Niagara Rosada' grafted onto the 'IAC 572' rootstock extracted the largest quantity of K, P, Mg, S, Cu, and Fe, differing from 'IAC 313' and 'IAC 766' in K and P extraction, and from '106-8 Mgt' in Mg and S extraction. Winter pruning results in higher yield, dry matter accumulation by branches, and total nutrient content and extraction.