Influence of grapevine rootstock/scion combination on rhizosphere and root endophytic microbiomes

Wine aging with oak chips is nowadays a common alternative to barrel aging, aiming to improve wine quality through the fast extraction of wood derived compounds. From the pool of wood phenols, ellagitannins have been reported to have the most significant impact on the wine’s organoleptic profile. Their final concentration in wines is influenced by several factors, with toasting level considered as one of the most important.

Irrigation is an important practice to influence vine quality, especially in Mediterranean regions, characterized by hot summers and severe droughts during the growing season. This study focused on deficit irrigation regime influence on amino acids composition of Monastrell grapevines under semiarid conditions (Albacete, Southeastern of Spain). In 2019, two treatments were applied: non-irrigation (NI) and regulated deficit irrigation (RDI), watered at 30% of the estimated crop evapotranspiration from fruit set to onset of veraison. Grape amino acids content was analyzed by HPLC. Berries from non-irrigated vines showed higher concentration of several amino acids, such as tryptophan (73%), arginine (70%), lysine (36%), isoleucine (27%), and leucine (21%), compared to RDI grapes. Arginine is, together with ammonium ion, the principal nitrogen source for yeasts during the alcoholic fermentation; while isoleucine, tryptophan, and leucine are precursors of fermentative volatile compounds, key compounds for wine quality. Moreover, NI treatment increased in a 14% the total amino acids content in grapes compared to RDI treatment. The reported effects might be because yield was 70% higher in RDI vines than in the NI ones and, therefore, the sink demand was increased in the irrigated vines. In addition, NI vines suffered more severe water stress and it is known that the amino acids synthesis and accumulation can be influenced by the plant response to stress. According to the results, the irrigation regime showed effect on amino acids concentration in Monastrell grapes under semiarid conditions. Grapes from non-irrigated vines showed a higher content of several amino acids relevant to the fermentative process and to the wine aroma compounds formation. It is demonstrated that the final content of nitrogen-related components in grapes is influenced by the irrigation regime. The convenience of the irrigation strategy to suggest will depend on the desired wine style and the target yield levels.

Plant diseases are a major obstacle to crop production. The main approaches to battle plant diseases, consist of synthetic chemicals to attack infecting pathogens. However, concerns are increasing about the effects of chemicals in the environment, leading to an increase in the use of biocontrol agents (BCAs), due to their assets, such as, antagonism, and competition. In this study, we tested the hypothesis that the introduction of Bacillus subtilis PTA-271 (Bs PTA-271) and Trichoderma atroviride SC1 (Ta SC1) produce distinctive modifications in the composition and network structure of the grapevine rhizosphere microbial community, as well as grapevine induced defenses.

According to the different concern of the ‘traditional’ and the ‘new’ wine-producing Countries, a variable importance is recognized to the climate/soil and to grapevine cultivars as factors affecting the wine quality. However, the viticultural experience can state that, within each area, climate and soil plays an incontestable role in affecting grape quality, and consequently wine quality, as well as the genetic characteristics of the cultivar.

In 2022, the area cultivated with grapes in Brazil counted 75 thousand ha. About 1/2 of the grape production is located in rio grande do sul state, in South Brazil. Nonetheless, the northeast region, especially the Sao Francisco River Valley (SFRV), is increasing its area and production, mainly pushed by table grapes. The states of bahia and pernambuco already respond for circa 1/3 of brazilian grape production.