“…The search for QTLs relating to grape berry acidity has seen a lot of activity in the last decade, with some promising breakthroughs for total or titratable acidity (Liang et al, 2011;Duchêne et al, 2014;Ban, 2016), pH (Viana et al, 2013;Chen et al, 2015), MA (Chen et al, 2015;Duchêne et al, 2020) and various acid ratios in young berries (Houel et al, 2015), however in most cases there was no satisfactory marker for TA level (Liang et al, 2011;Viana et al, 2013;Chen et al, 2015;Bayo-Canha et al, 2019). This may be due to the involvement of several biochemical steps and potential sites of regulation, as well as other factors that affect berry acid levels such as potassium accumulation (Duchêne et al, 2020). Despite these challenges, two major QTLs for TA concentration on linkage groups LG7 and LG4 were stably detected using a Picovine x Ugni Blanc flb population under different environmental conditions (Houel et al, 2015).…”