Interspecific parasitism in the Gymnosperms: Unpublished data on two endemic New Caledonian Podocarpaceae using scanning electron microscopy

Abstract

Parasitism of Parasitaxus ustus (Vieillard) de Laubenfels relative to Falacatifolium taxoides (Brongniart et Grisebach) de Laubenfels is the only presently known case in the Gymnosperms. The idea of parasitism between the two species is recent. Microphotographs usings SEM were done at different levels of the host and parasite. Penetration of the parasite up to the cambium of the host is accomplished under the form of fascicular system. The haustorial apparatus is localized at the level of the cambium. Host and parasite are infested by an mycelian endophyte showing appressoria and VA. Fungal fruiting bodies (fructifications) show a characteristic conidiocarp of the Fungi imperfecti (Deuteromycotina). It seems that this unique parasite is linked to a mycelian symbiosis. © Société botanique de France 1994.