Biological diversity (biodiversity) encompasses the variety of life forms occurring in nature, from the ecosystem to the genetic level, as a result of evolutionary history (Wilson 1992). The idea that fungi form a kingdom distinct from plants and animals gradually became accepted only after Whittaker (1969). Presently, the “fungi” as a mega-diverse group span three kingdoms, most belonging to the Fungi (Eumycota), while others are classified in the Protozoa and Chromista (Straminipila) (Cavalier-Smith 1998, James et al. 2006b). The word “fungi”, lower case and not in italics, is commonly used as a collective term for organisms traditionally studied by mycologists from all three kingdoms (Hawksworth 1991). The myxomycetes have also been traditionally studied by mycologists (Everhart & Keller 2008, Rojas & Stephenson 2008), and are included here.

Estimates for the number of fungi in the world range up to ca. 13.5 M species (McNeely et al. 1990, Hawksworth 1991, 2001, Hawksworth & Kalin-Arroyo 1995, Hyde 1996, Hyde et al. 1997, Tangley 1997, Groombridge & Jenkins 2002, Brusca & Brusca 2003, Rossman 2003, Crous et al. 2006, Adl et al. 2007, Kirk et al. 2008). It might be expected that the predicted numbers of fungi on Earth would have been considerably greater than the 1.5 M suggested by Hawksworth (1991),which is currently accepted as a working figure although recognized as conservative (Hawksworth 2001).

The 10th edition of Ainsworth & Bisby’s Dictionary of the Fungi (Kirk et al. 2008) provided a total of 98 998 for the number of fungal species accepted to date (excluding taxa treated under Chromista and Protozoa). Kirk et al. (2008) reported 1 039 species chromistan fungal analogues and 1 165 as protozoan in which 1 038 are regarded as protozoan fungal analogues: Percolozoa (Acrasida), Amoebozoa (Dictyostelia, Myxogastria, Protostelia), Cercozoa (Plasmodiophorida) which were previously treated as Myxomycota and Plasmodiophoromycota.

Egypt’s geographical position at the junction between two large continents (Africa and Asia), and its inclusion as part of the Mediterranean basin, has indelibly influenced both the people and the biota of the country socially, economically and biologically. Egypt is part of the Sahara of North Africa, it has an area of about 1 M km2, divided by the River Nile into a western part including the Libyan Desert (681 000 km2) and an eastern part comprising the Eastern Desert (223 000 km2), and the Sinai Peninsula (61 000 km2). The Nile basin, comprising the valley in the south (Upper Egypt) and Nile delta in the north (Lower Egypt), forms a riparian oasis (40 000 km2) that constitutes the densely inhabited farmlands of Egypt.

Kassas (2002) mentioned four gaps related to biodiversity knowledge: the number of species on Earth; the diversity of the less conspicuous organisms such as fungi, bacteria, algae, and protozoa; the role played by each species among biotic elements of ecosystems; and the human ability to assess and forecast bio-ecological degradation.