Polyphenols as potential markers to differentiate juvenile and mature chestnut shoot cultures

The phenolic contents of eight in-vitro-cultivated chestnut clones (Castanea sativa Mill. and C. sativa x C. crenata Siebold & Zucc. hybrids) were analyzed both qualitatively and quantitatively. The aim of the work was to identify potential phenolic markers of: (i) juvenile or mature state; (ii) topophysical origin; and (iii) rooting capacity. A condensed tannin was detected in mature material but not in juvenile material, indicating that it could be used as a qualitative marker. Other qualitative phenolic differences were found between basal shoots and crown shoots of some clones, but it was not possible to discriminate among these materials in a general way. Canonical discriminant analysis was used for the study of quantitative markers. Differentiation between mature and juvenile material, and between materials differing in in vitro rooting capacity was possible according to the results of the analysis. Nevertheless, no significant quantitative differences were found between the phenolic content of material of basal shoot origin and that of crown shoot origin, indicating that the greater juvenility of material of basal origin compared with that of crown origin was not reflected in differences in phenolic content.