Retrospective analysis of our knowledge regarding the genetics of relevant traits for rootstock breeding 

Antagonistic yeasts applied to wine grapes must be compatible with the thereafter winemaking process, avoiding competition with the fermentative Saccharomyces cerevisiae or affecting wine flavour. Therefore, fifteen epiphytic yeasts (6 Metschnikowia sp., 6 Hanseniaspora uvarum, 3 Starmerella bacillaris) previously selected for its biocontrol ability against Alternaria on wine grapes were evaluate for possible competition with S. cerevisiae by the Niche Overlap Index (NOI) employing YNB agar media with 10 mM of 17 different carbonate sources present in wine grapes (proline, asparagine, alanine, glutamic acid, tirosine, arginine, lisine, methionine, glicine, malic acid, tartaric acid, fructose, melibiose, raffinose, rhamnose, sucrose, glucose).

The ongoing climate change implies an increasing mean air temperature, which is signified by weather extremes or sudden changes between drought and local heavy rainfalls. These changing conditions are especially challenging for the established grapevine varieties growing under cool climate conditions due to an increased risk for fungal diseases like downy mildew (DM) and Botrytis bunch rot (BBR) as well as for grape sunburn. To meet that demand, the scope of most grapevine breeding programs is the selection of mildew fungus-resistant and climatic adapted grapevines with balanced, healthy yield and outstanding wine quality.

The wine spoilage caused by Brettanomyces bruxellensis is one of the global concerns for winemakers. Detecting the presence of B. bruxellensis using routine laboratory culture techniques becomes challenging when cells enter the viable but not culturable (VBNC) state. This study aims to investigate the impact of p-coumaric acid (a volatile phenol precursor) and micronutrients on B. bruxellensis’ culturability, viability, and volatile phenol production under sulfite stress. In red wine, exposure to a high sulfite dose (100.00 mg L-1 potassium metabisulfite) resulted in immediate cell death, followed by a recovery of culturability after two weeks.

The seminar will examine the complexities and prospects of genomic research on Vitis species, characterize by exceptionally high heterozygosity and common interspecific gene flow. The seminar will showcase case studies highlighting the critical role of diploid genome references in grape research, specifically in areas such as aroma development, disease resistance, and domestication traits. It will also address the emerging focus on pangenomes within the Vitis genus, particularly in the context of genetic studies on naturally interbreeding populations.

Trichoderma is a microorganism present in many agricultural soils and some of its species could be used as natural biological control agents. In this work, the presence of natural populations of Trichoderma was estimated in soil vineyard and its biocontrol capacity against Phaeoacremonium minimum, one of the main agent causals of grapevine trunk diseases instead of using pesticides. Moreover, physicochemical variables in soil such as pH, organic matter and nutrients were evaluated to determine a possible correlation to natural populations of Trichoderma.