Introduction to Fungi, Third Edition

PLEOSPORALES
471
Fig17.11
Alternaria brassicae. (a) Conidiophores and conidia. (b) Conidia. Note the long conidial beaks.
in human food and animal feed. Spores of
Alternaria spp. are abundant in the air in late
summer and autumn and may be a cause of
inhalant allergy causing asthma. Some species,
e.g. ‘A. alternata’, A. infectoria and A. longipes are
rare opportunistic human pathogens, associated
with diseases of bone, cutaneous tissue, ears,
eyes, nose and the urinary tract (Schell, 2003).
Other species are insect pathogens.
17.2.7 Cochliobolus
In Cochliobolus, the pseudothecium is long-necked
and contains elongate, transversely septate
ascospores spirally coiled around each other
within a vestigially bitunicate ascus (see
Figs. 8.15b d).
Anamorphs associated with Cochliobolus
The genus Cochliobolus contains some of the
best-studied and most highly damaging plant
pathogens. As in other Loculoascomycetes,
the taxonomic history of this genus has
been tortuous (Sivanesan, 1987; Alcorn, 1988);
the anamorphs were formerly classified in
Helminthosporium, then transferred to Drechslera,
and are now called Bipolaris (Fig. 17.13) and