Basidiomycetes

Rohan was playing cards with his cousins.

They were having fun time, laughing and joking together in between their game.

And suddenly Rohan noticed something and exclaimed - “Oh! So this is the club shape”.

His cousins confusingly asked - “What”?

He told them - “You know, there are some fungi called as club fungi!” One of the cousin asked - “But why are they called so?”

“Because they have club-shaped structures called as basidium”

Let us see what makes these club-fungi special.

Basidiomycetes is the class of fungi commonly called as club-fungi.

They are called so, because they produce club shaped reproductive structure called as basidium which bears 4 spores (basidiospores) at its tip.

It starts with formation of a primary mycelium which develops by germination of basidiospores, just like a plant start its life from a seed.

Primary mycelium have manokaryotic cells (contains single haploid nuclei) and it multiplies by oidia, conidia and pycniospores.

The primary mycelium does not contain distinct sex organs but fusion takes place between a spore and a hyphae or two hyphae cells of different mating types.

Plasmogamy (fusion of protoplasms) takes place resulting in formation of a dikaryon while karyogamy (fusion of nucleus) is delayed for long.

The phase between plasmogamy and karyogamy is called as dikaryophase and it produces a new mycelium, called as secondary mycelium.

Secondary mycelium gives rise to basidium in which karygomay and meiosis takes place

Each basidium produces four basidiospores that are produced exogenously at tips of fine outgrowth called sterigmata.

Advance forms of basidiomycetes may produce fruiting bodies called basidiocarps

One such advanced form is mushroom.

Agaricus campestris is commonly known as mushroom, they are edible and often grows in rings, called as 'fairy rings’.

It has underground assimilative part and what we see as mushroom above ground is reproductive part or basidiocarp.

These basidiocarps or fruiting bodies are formed from secondary mycelium under abundant food and favorable conditions.

Young fruiting bodies that are just arising from soil are known as button.

Button is spherical in shape and covered by thin membrane called as velum which ruptures during growth.

And remains of velum is left on stipe like a ring, called as annulus.

While on undersurface of cap-like pileus there are several plate-like structures called as gills or lamellae

These gills extend from central to edge of pileus like spokes of a wheel and they contain innumerable basidiospores.

Many other fungi also produces basidiospores, hence included in class basidiomycetes.

Lets see some examples of basidiomycetes.

Puccinia causes rust diseases in plants like wheat, sorghum, pea, coffee etc.

Ustilago causes smut diseases producing thick-walled black colored spores called as smut spores

Polyporus species causes wood rots and they are examples of bracket fungi or shelf fungi.

These bracket fungi grow on tree trunks, logs, timbers etc.

Clavatia produces an anticancer substance called as clavicin.

Toadstools are poisonous mushrooms and Amanita caesarea which was used to kill Roman emperor Caesar is an example.

Amanita phalloids (death cup), A. muscaria produces an alkaloid muscarine.

Gynomitra esculenta produces heat labile toxin.

Psilocybe mexicana has hallucinogenic properties and called as sacred fungi because it was used by Mexican Indians for religious ceremonies.

Puffballs at young state and honey mushrooms (Armitaria mellea) are edible examples.

Revision

Basidiomycetes is a class of fungi that includes members showing club-shaped structures called as basidium which bears four basidiospores.

They show two types of primary and secondary mycelium in their body.

Agaricus campestris is commonly known as mushroom and it is well known edible example of basidiomycetes.

Other members like Puccinia and Ustilago cause diseases like rusts and smuts respectively.

Toadstools are poisonous while bracket fungi (Polyporus species) are found growing on tree trunks, logs, timbers.

Puffballs ( Lycoperdon species) and honey mushrooms (Armitaria mellea) are examples of edible mushrooms.

The End