Composition of phenolic compounds in pear leaves as affected by genetics, ontogenesis and the environment

HPLC analysis of pear (Pyrus communis L.) leaf extracts to study the phenolic composition of the pear cvs. ‘Abbé Fétel’, ‘Williams’, ‘Max Red Bartlett’, ‘Packam's Triumph’ and ‘Passa Crassana’ showed a certain homogeneity as well as quantitative differences among cultivars. The concentrations of the single compounds were influenced by environmental conditions (orchard, glasshouse, in vitro) as well as by ontogenetic leaf age. A transient accumulation of some compounds, especially flavan-3-ols, was also detected after leaf wounding, thus confirming the role of phenolic compounds in resistance to injury and stress.