Introduction

The European Council for the Conservation of Fungi, during its fourteen years of activity, focused attention on threats and conservation problems of fungi. As a result of meetings, workshops and discussions, several regional and national Red Data lists as well as a preliminary European Red Data list (Ing, 1993), have been published.

A decline in the number of species of macrofungi has been reported from different European countries (Arnolds & Jansen 1991). Hypogeous species must also be included among the threatened fungi although hypogeous fungi form a special ecological group of macromycetes because their fruit bodies originate and remain underground until they break down naturally.

Elaphomyces is the most common genus in the northern part of Europe and includes several species that are under threat. Tuber is the best-known genus of hypogeous fungi in the Mediterranean area. Maturity of the fruit bodies of many species is indicated by a strong pleasant smell. Indeed, the aroma of truffles has attracted attention since ancient times and there are some highly valued species of the genus Tuber, such as T. melanosporum, T. brumale and T. aestivum, which have been exploited for consumption since prehistoric times. In the history of western civilisation, truffles were a frequent subject of research by natural philosophers. Because of the high culinary value assigned to these fungi even early scientists like Theophrastus, Dioscorides and Pliny tried to investigate their nature and biology (Pegler, Spooner & Young, 1993).