Asexual & Sexual Reproduction in Fungi

Asexual  Reproduction in Fungi

 This can be accomplished in several ways

1. A parent cell can divide into two daughter cells by central constriction abd

formation of new cell wall- (conidium)

Transverse fissure forming new cell wall

2. Somatic vegetative cells may bud to produce new organisms. This is common in

yeasts.

3. The most common method of asexual reproduction is spore production. Asexual

spore formation occurs in an individual fungus through mitosis and subsequent

cell division. There are several types of asexual spore.

a. Hypha can fragment to form cells that behave as spores. These cells are

called arthroconidiao or athrospores.

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Fragmentating hypahe

Arthroconidia

(Arthrospores)

b. If the cells are surrounded by a thick wall before separation, they are

called chlamydospores

Terminal Chlamydospores

Chlamydospores with a hypha

c. If the spores develop within a sac ( sporangium/ sporangia) at a hyphal tip,

they are called sporangiospores

Sporangiospores

Sporangium

Sporangiosphore

d. If the spores are not enclosed in a sac but produced at the tips or sides of

the hypha, they are called comdiospores.

coniodospores

coniodosphore

e. Spores produced from a vegetative mother cell by budding are called

blastospores.

Blastospores

Sexual Reproduction in Fungi

Involves the union of compatible nuclei. Some fungal are self-fertilizing and produce

asexually compatible gametes on the same mycelium- homothallic

Other species require out crossing between different but sexually compatible myceliaheterothallic.

Sexual reproduction yields spores. For example in the zygomycetes the zygote develops a

zygospore, in the ascomycetes, an ascospore, in the basiocomycetes a basidiospore.

Fungal spores are important for several reasons:

1. The size, shape colour and number are useful in the identification of fungal

species.

2. For fungal dissemination