Could orchids indicate truffle habitats? Mycorrhizal association between orchids and truffles

Abstract

Each member of the Orchidaceae family is in symbiosis with fungi. It has been explicitly stated that some forest orchid species are mycorrhizated by ectomycorrhizal fungi con- nected to trees, instead of classic orchid symbionts. These orchids supply their required nutrients via fungi. Our investigation aimed at analysing the data of a computerized database on hypo- geous fungi. This database contains the data on hypogeous fungi gathered in the Carpathian basin, and also the coenological releves made in their quadrat. We have found 16 hypogeous fungal genera with close presence of orchids (genus Cephalanthera and genus Epipactis), that is l3 % of all releves. In case of two fungal genera (Tuber and Hymenogaster) the orchid co-oc- curence proved to be more frequent than average, so these fungal taxons were supposed to be in mycorrhizal connection with the orchids. Tuber maculatum, and Tuber excavatum species were identified based on nrITS sequence analysis of three orchid individuals. Tuber maculatum