IDENTIFICATION OF HYDROXYCINNAMIC AND PHENOLIC ACIDS IN MNIUM HORNUM AND BRACHYTHECIUM RUTABULUM AND THEIR POSSIBLE ROLE IN PROTECTION AGAINST HERBIVORY

Abstract

  Observations in the field suggest that moss shoots are not commonly grazed, but immature capsule damage by slugs is abundant. In an investigation of the palatability of the mosses, Mnium hornum and Brachythecium rurabulum, to slugs in the family Arionidae it was found that the slugs ate considerably more immature capsule than leafy shoot. Phenolics have proved to be effective deterrents to molluscan feeding both in brown algae and in angiosperms. Therefore the phenolic component of the moss shoot and immature capsule was compared using HPLC, PC and TLC analysis to discover whether phenolic concentration can be correlated with low consumption. Nine phenolic compounds were identified, some within the cell and some wall-bound. Ferulic and possibly m- or p-coumaric acid were concentrated in the wall-bound fraction of the shoot. Other phenolics were concentrated within the immature capsule or were common to both moss tissues. The extraction and isolation of these compounds is discussed in relation to the form and location of a possible feeding deterrent.