Manunta, C. and M. Lafon.
In F1 hybrids, for most of the racial crosses under investigation, an intermediate value has been found for the chief component, citric acid, between the two parents, with a tendency toward the lower parental value. For other acids, no consistent rule can be stated (perhaps because of the too little quantity).
Investigating the F2 progenies of crosses between breeds with high and low acidity it should be possible to study the genes ruling the level of the synthesis of citric acid (like Nile Nyboom has made for malic acid in apples).
Such an investigation should open the best way to an improvement of good comercial breeds having the defect of a high acidity (high value of the ratio "acidityt optical residue"). Our observations on F1 hybrids already give an indication of the method to be followed.