Proanthocyanic polymorphism in holm oak (Quercus ilex L) in the Mediterranean region of France

We studied the proanthocyanic diversity of holm oak in France. The percentage of prodelphinidin remains constant for each individual tree, independent of age or location of the leaves. By contrast, this content can be significantly different between trees within the same population. An in-depth analysis of a Languedocian population showed a good relationship between observed and predicted sample structure, according to the hypothesis of 2 alleles, prodelphinidin 'weak' and 'strong', respectively, governing the biosynthesis of this polyphenol. We have probably observed a biochemical polymorphism comparable to that previously demonstrated for several coniferous species.