Electron Microscopy of the Epidermis and Cuticle of the Needles of Pinus nigra var. maritima in relation to infection by Lophodermella sulcigena

Abstract

Changes in the ultrastructure of the epidermis and cuticle of Corsican pine (Pinus nigra var. maritima (Aiton) Melville) in relation to infection of the needle by Lophodermella sulcigena (Rostr.) v Hohn were recorded throughout a growing season. Epidermal cells when young had thin walls and a thin smooth cuticle: both structures thickened with age, and the needle surface became rough. Densely packed wax tubes developed around the stomatal pore and later became scattered over the needle surface. The micro-flora present on the needles is briefly noted. Changes in the structure and micro-flora of needles as they aged are thought to contribute to the confinement of infection by L. sulcigena to the needle bases.