Juvenile-to-adult vegetative phase transition in grapevine 

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.

The SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) is a key floral activator that coordinates external and internal stimuli to ensure timely flowering. During early stages of flower formation, SOC1 represses floral organ identity genes such as AGAMOUS (AG) to prevent premature organ differentiation. In addition to floral organ specification, AG has been shown to regulate fleshy fruit expansion and ripening and, as such, is an important contributor to fruit quality traits. Currently, little is known about the function and gene regulatory network of the grapevine homologs VviSOC1a and VviAG1. As such, the aim of this study was to functionally characterise both genes by overexpressing them in tomato and performing phenotypic and gene expression studies.

Consumers are increasingly requesting ready-to-eat products, which are time-saving and convenient. Offering ready-to-eat fruits and vegetables represents a quick and easy way for any consumer to add healthy products to their diet. In this study, we evaluated the aptitude of several table grape varieties to be included in the processing and packaging lines of ready-to-eat products. The following work was based on the characterization of genetic materials and varietal innovation.

The effect of cover crop on the water relations, yield and grape composition of Pinot noir vines was investigated during two seasons (2003 and 2004) in a gravely soil located in Tarragona (Spain). Seventeen-year-old vines, grafted onto R110 and trained onto a Ballerina training system, were used.

Insufficient acidity in grapes from warm(ing) climates is commonly corrected through addition of tartaric acid during vinification, and less so with other organic acids. One alternative approach involves bio-acidification with certain strains of Lachancea thermotolerans (LT) via lactic acid production during fermentation.