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Deuteromycetes: Structure
heterokaryosis
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Deuteromycetes: Reproduction
- Asexual
- Haploid nuclei that are genetically different occasionally fuse, leading to recombination and a new nucleus
- - The restoration of the haploid condition does not involve meiosis
- Whole sequence (plasmogamy, karyogamy, and haploidization)= parasexuality
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Deuteromycetes: Relevance
- Penicillium
- -some cheeses
- -antibiotics (Penicillin)
- -food spoilage
- Aspergillus
- -spoilage
- -attacks peanuts
- -produces aflatoxins
- One group produces ring worm and other fungal skin diseases
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Basidiomycetes: Structure
- Produce basidiospores, which are borne outside the basidium
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- Mycelium is always septate,, but the septa are perforate with a barrel-shaped margin called a dolipore with membranous caps (parenthesomes) on either side
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- Mycelium can be monokaryotic and dikaryotic during the life cycle
- Clamp connections
- Has a stipe and pileus, as well as gills
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Basidiomycetes: reproduction
Reproduce mainly through forming basidiospores
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Basidiomycetes: relevance
- Important for decomposing plant litter
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- Cause wheat rust and corn smut
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Sexual Life Cycle of Basidiomycetes
- a. Basidia form in well-defined hymenia that are exposed before the basidiospores are mature from a terminal cell of a dikaryotic hypha
- b. Karyogamyà meiosisà four haploid nuclei, which migrate into a sterigma, which enlarges at its tip to form a uninucleate, haploid basidiospore
- c. Mitosisà 8 haploid spores
- i. Post meiotic mitosis may occur in the basidium, the sterigmata, or the young spore
- d. At maturity, the basidiospores are discharged from the basidioma and are dispersed by the wind
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Sexual Life Cycle of Rust Fungi that cause Wheat Rust
- 1) Early spring: barberry bush infected by uninucleate basidiospores
- 2) The hyphae of hte basidiospores (+ and -) give rise to + and - spermogonia
- 3) when the spermatia from one strain come in contact with the receptive hyphae of the opposite strain--> plasmogamy and formation of aecia
- 4) n+n aeciospores are produced--> infect wheat (reddish streaks called uredinia)
- 5) Uredinia contain single-celled, dikaryotic urediniospores--> reinfect the wheat
- 6) Late summer and early fall: Streaks are converted to dark-colored telia containing teliospores
- 7) karyogamy occurs and teliospores overwinter
- 8) early spring: germination of teliospore--> mitosis--> basidium and four haploid basidiospores
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