There are also some infamous Ascomycota a few of the worst being Aspergillus

There are also some infamous ascomycota a few of the

This preview shows page 36 - 39 out of 72 pages.

There are also some infamous Ascomycota, a few of the worst being: Aspergillus flavus , producer of aflatoxin, Candida albicans , cause of thrush, diaper rash and vaginitis, and Asexual Ascomycota, such as Penicillium or Candida species, used to be classified separately in the Deuteromycota because sexual characters were necessary for Ascomycota classification. Molecular techniques have permitted the integration of asexual fungi into the Ascomycota. The Deuteromycota is no longer recognized as a formal taxon in fungal systematics. Ascomycota produce ascus where nuclear fusion and meiosis take place. In the ascus, ascospores are formed. 36
Image of page 36
The thick-walled haploid ascospores are resistant to adverse environments but, will germinate in conducive environment to form a new haploid fungus. The body can be a single cell, as in yeasts, or a long tubular filament divided into cellular segments, which is called a hypha Ascomycota are heterotrophs and play a big role in recycling dead plant material. Some are parasitic - Pneumocystis carinii , responsible for pneumonia of humans and Ophiostoma ulmi , responsible for the demise of elm trees in North America and Europe. 4. BASIDIOMYCOTA Basidiomycota is one of two large phyla often referred to as the "Higher Fungi" ) within the Kingdom Fungi. More specifically the Basidiomycota include mushrooms, puffballs, bracket fungi, smuts, and rusts. Basidiomycota are filamentous fungi composed of hyphae. They reproduce sexually via the formation of specialized club- shaped end cells called basidia that produce basidiospores. However, some Basidiomycota reproduce asexually, and may or may not also reproduce sexually. 37
Image of page 37
Asexually reproducing by the formation of a distinctive anatomical feature clamp connection . Three sub-phyla/classes 1. Agaricomycetes: Include fungi known as mushrooms, including the bracket fungi and puffballs. 2. Ustilaginomycetes: is the class of true smut fungi . (Ustilago maydis) They are plant parasites with about 1400 recognised species in 70 genera. 3. Pucciniomycetes : the rust fungi: Puccinia sorghi, Puccinia polysora Reproduction in fungi Fungal reproduction is complex. Some fungi use more than one type of reproduction, the telemorph (sexual) and anamorph (asexual) phase. Environmental conditions trigger the genetically determined developmental programs leading to an interchange in phases. Specialized reproductive structures for sexual or asexual reproduction develop to aid spore production and their dispersal. Asxual phase: Asexual reproduction is via vegetative spores (conidia) or through mycelial fragmentation It allows more rapid dispersal than sexual reproduction. Sexual phase: Sexual reproduction with meiosis exists in all fungal phyla (except Glomeromycota- abarscula mycorhizae).
Image of page 38
Image of page 39

You've reached the end of your free preview.

Want to read all 72 pages?

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture