or small and produce hyaline and smooth or
angular zygospores with apposed suspensors
[Fig.8.3(27)] that are surrounded by hyphae in
a few species(Kirk et al. 2008 ).The bases of the
sporangiophores are often inflated [Fig.8.3
(24)], and the colony may produce a garlic- or
onionlike odor(Hoffmann et al. 2011 ; Petkovits
et al. 2011 ). These fungi are discussed and illu-
strated by Gams ( 1976 ,1977a,b) and Zycha
et al. ( 1969 ).
Mortierellomycotina is based on the phylo-
genetic analysis of a multigene data set com-
posed of 18S and 28S rRNA, actin,a- andb-
tubulin, and RPB1 and RPB2 genes (Hoffmann
et al. 2011 ), a separation supported by an anal-
ysis of fungal sterols (Weete et al. 2010 ).The
cardinal morphological traits for this subphy-
lum are the lack of a columella, basally inflated
sporangiophores, and the morphology of the
zygospore(Degawa and Tokumasu 1998 ; Kuhl-
man 1972 ). Some taxa produce a characteristic
odor andcolonies with a more or less regular,
flattened, wavy or undulate growth pattern
(Petkovits et al. 2011 ).
Petkovits et al. ( 2011 ) and Wagner et al.
( 2013 ) analyzed a phylogeny of Mortierellaceae
and observed that the clades did not correlate
with the sections ofMortierella[Gams1977a;
illustrated in Gams (1977b)]. The data set was
composed of 90 reference and type strains,
representing 53 different species ofMortierella
and four taxa from Dissophora, Gamsiella
[Fig.8.3(24)], andLobosporangium [Fig.8.3
(23)], from Mortierellales. Additional isolates
(more than 400) were included in a data set of
Mortierellales that demonstrated that the order
includes unresolved taxa, including species
complexes. Nagy et al. ( 2011 ) found 55 % of
the described taxa ofMortierella[Fig.8.3(26)],
but there may eventually be 127 species world-
wide by the time all members of the genus are
described. Kirk et al. ( 2008 ) estimate that
approximately 85Mortierellaspp. have been
described. Hibbett and Glotzer ( 2011 ) revealed
that of all the species of the Mortierellales
described in the last 140 years by taxonomists,
approximately 50 % of these taxa were found in
6 years by molecular ecologists.
One taxon,Aquamortierella(Embree and
Indoh 1967 ), has appendaged sporangiospores
and is known only in aquatic habitats. Other
taxa in Mortierellales areDissophora, a psy-
chrophile found on dung and in soil (Benny
1995 ; Thaxter 1914 ),Echinochlamydosporium,
which colonizes soybean cyst nematode
juveniles (Jiang et al. 2011 ), and Gamsiella
[Fig. 8.3(24)] and Lobosporangium [Fig. 8.3
(23)], both isolated from soil or humus
(Benny and Blackwell 2004 ). The aforemen-
tioned taxa are all known from one or two
reports in the literature. The majority of the
species, however, are members of the genus
Mortierella[Fig.8.3(26)] (Gams1977a). Spor-
ocarps ofModicella [Fig.8.3(25)] have been
collected numerous times in the field and sev-
eral reports have been published on the genus.
Modicella has two known species that have
never been cultured (Gerdemann and Trappe
1974 ).Nothadelphiais a genus that is parasitic
on a species ofMortierella; it may be a member
of Mortierellales, but its true affinities are
unknown (Degawa and Gams 2004 ).- Mucoromycotina
a) Endogonales
This order was validated by Benjamin ( 1979 ).
The members of Endogonales [Fig. 8.4(28,
29)] are either saprobes or ectomycorrhizal
(Warcup 1990 ) and reproduce by forming
zygospores with apposed suspensors [Fig.8.4
(29)] in uni- or multizygosporic sporocarps
[Fig. 8.4(28)]. Historically the members of
Endogonales have been associated with the
endomycorrhizal fungi (Morton and Benny
1990 ). Initially, members of Endogonales (as
the family Endogonaceae) were in the order
Mucorales (Hesseltine and Ellis 1973 ). The
members of Endogonales consisted only of
sporocarpic taxa inEndogone(Thaxter 1922 ),
including species now in Glomeromycota
(Schu ̈ssler et al. 2001 ).
The zygospores ofEndogone pisiformisLink
have been studied ultrastructurally from sporo-
carps collected in the field [Fig.8.4(28, 29)] (Gib-
son et al. 1986 ). Cultures made from germinating
zygospores and grown on ordinary laboratory
culture media only form mycelium (Dalpe ́ 1990 ).
Sporocarps ofE. pisiformishave been produced in
Zygomycetous Fungi: Phylum Entomophthoromycota and Subphyla Kickxellomycotina,... 233