Harmful Fungi

Several agricultural plants like sugarcane, maize, cereals and vegetables suffer from diseases caused by fungi.

1. Puccinia graminis (Wheat Rust)

It causes brown patches on leaf and stem of wheat plants. It decreases the yield of wheat and makes it unfit for human consumption.

2. Rhizopus or Bread Mould (grows on bread)

If the bread is exposed to warm and humid conditions, a cottony mass develops in few days. This white cotton mass later develops a greyish black colour, because of black coloured spores.

The whitish network is called mycelium. The mycelium contains thread like structures called hyphae. The root-like stuctures growing out of the hyphae penetrate the bread, and secrete digestive enzymes (extracellular digestion) and absorb the digested food.

Greyish black colour of the mould develops due to formation of sporangium which after rupturing release dark coloured spores. The spores scatter by wind and germinate after falling on a suitable substractum. This is asexual reproduction.

Sexual reproduction takes place by conjugation between two neighbouring hyphae to produce a zygospore which after a period of rest undergoes meiosis followed by several mitotic cell divisions to produce a germ sporangium having a large number of haploid unicellular spores. The germ sporangium differs from asexual sporangium, as it does not have columella. When mature, the germ sporangium bursts to release spores which germinate on meeting favourable conditions and produce a new mycelium.

3. Humans

In humans, skin diseases like ringworm and athlete’s foot are caused by fungi. Some ear infections are also caused by fungi.

Beneficial Fungi

Certain Mushrooms (such as Agaricus campestris) are edible. Yeast is used for fermentation during manufacture of bread, beer, soya sauce, cheese and wine.

Mycorrhizae are fungi associated with roots of plants. Roots benefit in getting minerals from the environment while fungi get food from the plant in return through such association.

Neurospora has been a favourite experimental material in Genetics.

Various antibiotics are derived from fungi. Penicillin is obtained from Penicillium notatum.