Stomatal restrictions to photosynthesis in grapevine cultivars grown in a semiarid environment

In the present work Schizosaccharomyces japonicus and Saccharomyces cerevisiae were inoculated simultaneously or in sequence in mixed fermentation trials with the aim of testing their ability to improve the overall quality of red wine

Grapevine downy mildew, caused by the oomycete Plasmopara viticola, is responsible for significant economic losses each year and for a large proportion of the fungicides used in viticulture.

Microbial pathogens of plant have evolved to sense, interpret, and use light to direct their development. One aspect of this evolved relationship is photolyase-mediated repair of UV-induced damage to pathogen DNA. Application of germicidal UV (UV-C) at night circumvents the blue light-driven repair of pathogen DNA and allows non-phytotoxic doses of UV-C to suppress a variety of pathogenic microbes and even certain arthropod pests without damage to vines or fruit. Lamps arrays have been designed specifically for the canopy architecture of grapevines and have been deployed on both tractor-drawn and robotic carriages for partial to near-complete suppression of powdery mildew (Erysiphe necator), sour rot (fungal, bacterial, and arthropod complex), and downy mildew (Plasmopara viticola).

In the 19th century, devastating outbreaks of phylloxera (Daktulosphaira vitifoliae Fitch), almost brought European viticulture to its knees. Phylloxera does not only take energy in form of sugars from the vine, but also affects the up- and down- regulations of genes, acts as a carbon sink and reprograms the physiology of the grapevines, including nutrient uptake and the defense system [1]. A key trait of rootstocks is the ability to perform well under high lime conditions as about 30 % of the land surface has calcareous soil. Iron deficiency not only causes the well-known problems of lime-induced chlorosis and stunted growth, but also affects the entire plant metabolism.

Recent advances in phenomics and transcriptomics have the enhanced capacity for understanding how clonally propagated perennial crops like grapevines respond to their environments seasonally and over the course of multiple years. Because most grapevines are grafted, above-ground grapevine traits reflect scion genotype and its interaction with the local environment. In addition, traits expressed by the scion reflect rootstock genotype and how that rootstock is interacting with its environment seasonally and across years. To investigate rootstock x environment interaction on shoot systems in grafted grapevines we characterized comprehensive phenotypic variation in an experimental vineyard in Mount Vernon, Missouri, USA where the grapevine cultivar ‘Chambourcin’ is growing on its own roots and is grafted to three different rootstocks (‘1103P’, ‘3309C’, ‘SO4’).