Page 5
3. Basidiomycota. The phylum is distinguished by its reproductive structure, the club-like basidium,
which contains the products of sexual reproduction called basidiospores. Germinating basidio-
spores produce a mycelium that develops septa as it grows. Hyphae of compatible mating types
conjugate to form a secondary mycelium. A tertiary mycelium develops to form the familiar
reproductive structures of mushrooms, puffballs, and bracket fungi. Some basidiomycetes, the
rusts and smuts, are serious crop pests, while others can be used for food or medical products.
Some members of this phyla can also be deadly because of their poison (Figure 4).
4. Deuteromycota. These fungi are often termed "fungi imperfecti" because they lack structures
for sexual reproduction. Only asexual reproduction is known to occur naturally, although some
genetic recombination has occurred under laboratory conditions. Germinating spores produce
mycelia with septate hyphae. The phylum includes economically important species like the patho-
genic Penicillium (Figure 5), source of the powerful antibiotic Penicillin. It also includes an interest-
ing genus of predaceous fungi, Arthrobotrys, which actively captures and feeds upon nematodes.
Biotechnology has enabled us to use the unique biochemical makeup of these organisms to our
advantage. Fungi are important in the processing of many foods, including tea, coffee, cheese, vinegar,
beverages, and breads. They are also influential in the manufacture of industrial chemicals such as
acetone, alcohols, and citric acid, as well as in the production of antibiotics and vitamins. Last, but by
no means least, is the recycling of organic matter. Fungi are vitally important in initiating the break-
down of matter through decay, helping to return vital nutrients to the soil.
Figure 4
Basidiospores
Basidium
Trama
Hypha
Hymenial Layer
Figure 5
Conidia
Sterigma
Metula
Conidiophore
Mycellium
Hypha
