Non-targeted analysis of C13-norisoprenoid aroma precursors in Riesling

A seven years survey (2003 to 2009) has been carried out over old traditional vineyards cv. Cencibel in La Mancha region (Spain). Seven plots with more than 35 years old were sampled from veraison to harvest, measuring soluble solids (ºBaumé) and acid concentration (g/l in tartaric acid).

Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with plant roots and can help plants acquire nutrients from the soil in exchange for photosynthetic carbon. Commercial bioinoculants containing AMF are widely available and represent a potential opportunity to reduce the dependence of grapevines on agrochemicals. However, which commercially available AMF species colonize vine roots and affect vine growth remains unknown. The aim of this study was to identify the AMF species from commercial bioinoculants that colonize grapevine roots using high-throughput sequencing, and to evaluate the performance of five commercial bioinoculants and their effects on own-rooted Cabernet sauvignon.

Random sampling is often considered to be the best protocol for fruit sampling because it is assumed to produce a sample that best represents the vineyard population.

Soil physical and chemical properties affect vine nutrition, as indicated by leaf and petiole nutrient content, in a way that may directly impact wine properties.

Grapevine is grown as a graft since the end of the 19th century. Rootstocks not only provide tolerance to Phylloxera but also ensure the supply of water and mineral nutrients to the scion. Rootstocks are an important mean of adaptation to environmental conditions, because the scion controls the typical features of the grapes and wine. However, among the large diversity of rootstocks worldwide, few of them are commercially used in the vineyard. The aim of this study was to investigate the extent to which rootstocks modify the mineral composition of the petioles of the scion. Vitis vinifera cvs. Cabernet-Sauvignon, Pinot noir, Syrah and Ugni blanc were grafted onto 55 different rootstock genotypes and planted in a vineyard as three replicates of 5 vines. Petioles were collected in the cluster zone with 6 replicates per combination. Petiolar concentrations of 13 mineral elements (N, P, K, S, Mg, Ca, Na, B, Zn, Mn, Fe, Cu, Al) at veraison were determined. Scion, rootstock and the interaction explained the same proportion of the phenotypic variance for most mineral elements. Rootstock genotype showed a significant influence on the petiole mineral element composition. Rootstock effect explained from 7 % for Cu to 25 % for S of the variance. The difference of rootstock conferred mineral status is discussed in relation to vigor and fertility. Rootstocks were also genotyped with 23 microsatellite markers. Data were analysed according to genetic groups in order to determine whether the petiole mineral composition could be related to the genetic parentage of the rootstock. Thanks to a highly powerful design, it is the first time that such a large panel of rootstocks grafted with 4 scions has been studied. These results give the opportunity to better characterize the rootstocks and to enlarge the diversity used in the vineyard.