Changes in the composition of volatile compounds of Spartium junceum induced by the phytoplasmal disease, Spartium witches’‐broom

Abstract

In southern Italy, Spartium junceum (Spanish broom) is severely affected by a phytoplasmal disease, Spartium witches’‐broom (SpaWB). The volatile fractions extracted from flowers of healthy and diseased plants, examined by gas chromatography and gas chromatography–mass spectrometry, appeared to be quantitatively and qualitatively different. In both the healthy and the diseased plants, the main components were n‐alkanes, which occurred at a rate of 55.2% and 38.8%, respectively. The level of aliphatic acids was considerably lower in flowers of the diseased plants than in those of the healthy plants (4.5% vs. 18.7%). Sesquiterpenes were detected only in the diseased plants. It is possible that the changes in the composition of secondary metabolites of diseased plants can be related to plant defense responses. Abbreviations: AP, apple proliferation; EY, elm yellows; SpaWB, Spartium witches’‐broom