Genetic Mapping of Organic Acids in Grapevine

Climate change will significantly influence grapevine production in coming decades. Especially white wine cultivars adapted to the cooler growing regions will lose their typical levels of organic acids in certain years. Next to the adverse organoleptic change, wine quality can also decrease due to an elevated pH-value which protects the fruit to a certain extinct against microbial attack in the field. Acidity in must is also necessary for a stable vinification process and prevents wines to become flat or flabby.

The acidity profile of a white berry F1 cross population (Gf.Ga-47-42 x ‘Villard Blanc’) was recorded in five successive growing seasons under field conditions at Geilweilerhof (Palatinate, Germany). The plants differ among other things in acidity level and maturity progress. Obtained data were used for QTL analysis to identify genetic regions involved in acidity leveling using an integrated genetic map consisting of 543 loci on 19 chromosomes. Regions of major genetic influence on acidity were identified and prove to be stable over the years.

The Knowledge about genomic regions with significant impact on acidity and other quality traits will enhance and accelerate the grapevine breeding progress. Newly identified trait-linked molecular markers are intended for application in marker-assisted selection (MAS). The desired grapevines are pathogen resistant and of high wine quality potential as well as adapted to the future climate conditions.

This study is financially supported by the Federal Ministry of Food and Agriculture (BMEL) through the Federal Agency for Agriculture and Food (BLE) within the Program for Advancement of Innovations.