200
E. IMRE FRIEDMANN AND MARGALITH GALUN
and is composed mainly of species of Pénicillium. In the soil of the dayas
(shallow sand basins with phanerogamic hamada vegetation), there is a
comparatively rich mycoflora composed mainly of Dematiaceae (Helminthosporium, Curvularia, Alternaria, and Stemphylium), as well as ascomycetes, Mucorineae, and some Fusarium spp. concentrated mainly in the
upper 5-cm-thick soil layer. Below this, the number of fungi sharply decreases and under 10 cm Aspergillus jumigatus Fres. (accompanied only
by a few other Aspergillus and Pénicillium spp.) is almost absolutely
dominant.
In the northern Negev Desert, Rayss and Borut (1958) and Borut
(1960) found a varied soil mycoflora. Borut listed 4 phycomycetes, 43
ascomycetes (3 Gymnoascaceae, 21 Pénicillium spp., 14 Aspergillus spp.),
and 35 deuteromycetes (4 Sphaeropsidaceae, 6 Mucedinaceae, 18
Dematiaceae, 2 Stilbaceae, 3 Tuberculariaceae, 3 Mycelia sterilia). Nour
(1956) found in virgin soils near Khartoum, Sudan species of Rhizopus,
Aspergillus, Alternaria, Curvularia, and Cladosporium.
Durrell and Shields (1960) isolated 41 micromycetes from soils of the
Neveda Test Site. The prevalent organisms were Stemphylium ilicis Tengwall, Fusarium sp., Phoma sp., and Pénicillium oxalicum Currie et Thorn.
Hunt and Durrell (1966) listed 48 species from the Death Valley, among
these were 10 species of Aspergillus, 2 of Curvularia, and 3 of
Stemphylium.
Khudairi (1969) described mycorrhizae from desert soils in Iraq, associated with roots of Phoenix dactylifera L., Zizyphus spina-christi Willd.,
and Peganum harmala L.
Fletcher and Martin (1948) found Rhizopus, Mucor, and possibly
Botrytis in desert raincrusts in Arizona, but no actinomycetes. In the
Atacama Desert, Cameron et al. (1965, 1966) and Opfell and Zeball
(1967) found a sparse mycoflora, consisting of Pénicillium sp. and
actinomycetes.
Myxomycètes also occur in deserts (Evenson, 1961). In southern Arizona, myxomycètes were "extremely common" in moist chamber cultures
of desert plant material, though the number of species was limited
[Badhamia macrocarpa (Ces.) Rost. Perichaena depressa Libert, P. vermicularis (Schw.) Rost.].
C. SOIL MICROMYCETES: ECOLOGY AND PHYSIOLOGY
Borut (1960), in agreement with other authors, points out that desert
soil micromycetes, though their number in the soil is generally less than
in nondesert regions, are generally species of world-wide distribution.
However, the species composition of desert soil mycofloras is characteris-
E. IMRE FRIEDMANN AND MARGALITH GALUN
and is composed mainly of species of Pénicillium. In the soil of the dayas
(shallow sand basins with phanerogamic hamada vegetation), there is a
comparatively rich mycoflora composed mainly of Dematiaceae (Helminthosporium, Curvularia, Alternaria, and Stemphylium), as well as ascomycetes, Mucorineae, and some Fusarium spp. concentrated mainly in the
upper 5-cm-thick soil layer. Below this, the number of fungi sharply decreases and under 10 cm Aspergillus jumigatus Fres. (accompanied only
by a few other Aspergillus and Pénicillium spp.) is almost absolutely
dominant.
In the northern Negev Desert, Rayss and Borut (1958) and Borut
(1960) found a varied soil mycoflora. Borut listed 4 phycomycetes, 43
ascomycetes (3 Gymnoascaceae, 21 Pénicillium spp., 14 Aspergillus spp.),
and 35 deuteromycetes (4 Sphaeropsidaceae, 6 Mucedinaceae, 18
Dematiaceae, 2 Stilbaceae, 3 Tuberculariaceae, 3 Mycelia sterilia). Nour
(1956) found in virgin soils near Khartoum, Sudan species of Rhizopus,
Aspergillus, Alternaria, Curvularia, and Cladosporium.
Durrell and Shields (1960) isolated 41 micromycetes from soils of the
Neveda Test Site. The prevalent organisms were Stemphylium ilicis Tengwall, Fusarium sp., Phoma sp., and Pénicillium oxalicum Currie et Thorn.
Hunt and Durrell (1966) listed 48 species from the Death Valley, among
these were 10 species of Aspergillus, 2 of Curvularia, and 3 of
Stemphylium.
Khudairi (1969) described mycorrhizae from desert soils in Iraq, associated with roots of Phoenix dactylifera L., Zizyphus spina-christi Willd.,
and Peganum harmala L.
Fletcher and Martin (1948) found Rhizopus, Mucor, and possibly
Botrytis in desert raincrusts in Arizona, but no actinomycetes. In the
Atacama Desert, Cameron et al. (1965, 1966) and Opfell and Zeball
(1967) found a sparse mycoflora, consisting of Pénicillium sp. and
actinomycetes.
Myxomycètes also occur in deserts (Evenson, 1961). In southern Arizona, myxomycètes were "extremely common" in moist chamber cultures
of desert plant material, though the number of species was limited
[Badhamia macrocarpa (Ces.) Rost. Perichaena depressa Libert, P. vermicularis (Schw.) Rost.].
C. SOIL MICROMYCETES: ECOLOGY AND PHYSIOLOGY
Borut (1960), in agreement with other authors, points out that desert
soil micromycetes, though their number in the soil is generally less than
in nondesert regions, are generally species of world-wide distribution.
However, the species composition of desert soil mycofloras is characteris-