Hormonal and associated metabolic changes in susceptible harvest-ripe grapes under asymptomatic and symptomatic Esca disease

A Região Demarcada do Douro, oferece uma diversidade geográfica, climática e biológica (grande número de castas em cultivo) extremamente grande e complexa, originando vinhas

Biocontrol using non-Saccharomyces yeasts is an alternative strategy to chemical additives to prevent the growth of spoilage microorganisms.

Traditional agricultural and agro-pastoral systems (prior to industrial revolution) often have the characteristic of being multiple systems, in which multiple crops are hosted simultaneously on the same plot. currently research suggests to study more in depth the potential of multiple agricultural systems in order to detect those characteristics of multiple agrarian systems that could allow modern viticulture to adapt to the challenges posed by climate change: rising temperatures with impacts on the phenological cycle of the vine, resurgence of plant deseases, extreme soil washout phenomena and hail storms, among others.

Atmospheric carbon dioxide (CO2) concentration has continuously increased since pre-industrial times from 280 ppm in 1750, and is predicted to exceed 700 ppm by the end of 21st century. For most of C3 plant species elevated CO2 (eCO2) improve photosynthetic apparatus results in an increased plant biomass production. To investigate the effects of eCO2 on morphological leaf characteristics the two Vitis vinifera L. cultivars, Riesling and Cabernet Sauvignon, grown in the Geisenheim VineyardFACE (Free Air Carbon dioxide Enrichment) system were used. The FACE site is located at Geisenheim University (49° 59′ N, 7° 57′ E, 94 m above sea level), Germany and was implemented in 2014 comparing future atmospheric CO2-concentrations (eCO2, predicted for the mid-21st century) with current ambient CO2-conditions (aCO2). Experiments were conducted under rain-fed conditions for two consecutive years (2015 and 2016). Six leaves per repetition of the CO2 treatment were sampled in the field and immediately fixed in a FAA solution (ethanol, H2O, formaldehyde and glacial acetic acid). After 24 h leaf samples were transferred and stored in an ethanol solution. Subsequently, leaf tissue was dehydrated using ethanol series and embedded in paraffin. By using a rotary microtomesections of 5 µm were prepared and fixed on microscopic slides. Subsequent the samples were stained using consecutive staining and washing solutions. Afterwards pictures of the leaf cross-sections were taken using a light microscope and consecutive measurements were conducted with an open source image software. Differences found in leaf cross-sections of the two CO2 treatments were detected for the palisade parenchyma. Leaf thickness, upper and lower epidermis and spongy parenchyma remained less affected under eCO2 conditions. The observed results within grapevine leaf tissues can provide first insights to seasonal adaptation strategies of grapevines under future elevated CO2 concentrations.

During wine storage and aging, microorganisms capable of degrading malic acid in an undesirable manner can proliferate.