• Most fungi reproduce Asexually and Sexually by spores • is most common method & produces genetically identical organisms • Fungi reproduce SEXUALLY when conditions are poor & nutrients scarce 2 Spores

• Spores are an adaptation to on land • Ensure that the will disperse to new locations • Each contains a reproductive cell that forms a new organism • Nonmotile • Dispersed by wind 3 Fungi are Spore-ific!!!

• Spores - asexual (product of ) or sexual (product of ) in origin. • Purpose of Spores – Allows the to move to new food source. – Resistant stage - allows fungus to survive periods of adversity. – Means of introducing new genetic combinations into a population Reproduce by spores

• Spores may be Formed: – Directly on hyphae – Inside sporangia – On Fruiting bodies

Penicillium hyphae

Amanita fruiting body Pilobolus sporangia Sporangio-aplanospores Hyphal growth from spore

Germinating spore

mycelium • Mycelia have a huge surface area • More surface area aids digestion & absorption of food 7 Zoospores

• Zoospores are MOTILE SPORANGIOSPORES - and the sporangia in which they form are called ZOOSPORANGIA.

• The protoplasm of zoospores is NOT surrounded by a wall - in some respects they resemble

flagellate protozoa. 8


• Because zoospores are motile, the fungi that produce them will require water at some stage during their life cycle.

9 Formation of conidia

• Conidia develop by SEPTATION and FRAGMENTATION of a hypha.

10 ASexual Reproduction

11 Asexual Reproduction

Asexually, fungi produce thousands of genetically identical haploid spores, usually on modified cells of the hyphae. When these spores are placed in favourable environmental conditions, they germinate and grow new hyphae, each of which can form a mycelium and produce thousands of new asexual spores Three types of Asexual Reproduction

• Fragmentation – part of the mycelium becomes separated & begins a life of its own • – a small cell forms & gets pinched off as it grows to full size – Used by

• Asexual spores – production of spores by a single mycelium 13 Asexual spores

• Fungi produce two major types of asexual spore:

• Sporangiospores: • ENDOGENOUS - formed and contained within a . • Formed as a result of the CLEAVAGE OF PROTOPLASM around nuclei. Followed by formation of a wall around

each nucleate portion of protoplasm. 14

Asexual spores

• Characteristic of fungi belonging to the and OOMYCOTA. • Two main types - ZOOSPORES (motile) and APLANOSPORES (non-motile)

• Conidia: • EXOGENOUS - often formed at the tip of supporting hyphae called a CONIDIOPHORES • Characteristic of fungi belonging to the ASCOMYCOTA and . 15 ASEXUAL REPRODUCTION

• Fruiting Bodies are modified hyphae that make asexual spores • An upright stalk called the Sporangiosphore supports the spore case or Sporangium


• Types of Sporangia Fruiting Bodies: – Basidia – Sporangia – Ascus

Basidia 17 Fruiting Bodies

Both are composed of hyphae

mycelium 18

19 SEXUAL REPRODUCTION • Used when environmental conditions are poor (lack of nutrients, space, moisture…) • No male or fungi • Some fungi show dimorphism – May grow as MYCELIA or a –LIKE state (Filament at 25oC & Round at 37oC) Dimorphic Fungi 20 SEXUAL REPRODUCTION • Haploid 1n hyphae from 2 mating types (+ and -) FUSE (Fertilization) • Forms a hyphae with 2 nuclei that becomes a ZYGOTE • The zygote divides to make a SPORE

+ -

21 SPORE FORMS Generalized Life Cycle of a Fungus