• Login
    View Item 
    •   Home
    • Brock Theses
    • Masters Theses
    • M.Sc. Biological Sciences
    • View Item
    •   Home
    • Brock Theses
    • Masters Theses
    • M.Sc. Biological Sciences
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of BrockUCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjectsProfilesView

    My Account

    LoginRegister

    Statistics

    Display statistics

    Light and electron microscope studies of host-parasite relations in a mycoparasite

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Brock_Golesorkhi_ Roya_1981.pdf
    Size:
    2.528Mb
    Format:
    PDF
    Download
    Author
    Golesorkhi, Roya.
    Keyword
    Host-parasite relationships.
    Parasites.
    Microscopes.
    Microscopy.
    Electron microscopes.
    
    Metadata
    Show full item record
    URI
    http://hdl.handle.net/10464/1936
    Abstract
    Light microscope studies of the mycoparasite Piptocephalis virginiana revealed that the cylindrical spores of the parasite became spherical upon germination and produced 1-4 germ tubes. Generally t"l.vO germ tubes were produced by each spore. When this parasite was inoculated on its potential hosts, Choanephora cucurbitarum and Phascolomyces articulosus, the germ tube nearest to the host hypha continued to grow and made contact with the host hypha. The tip of the parasite's germ tube became swollen to form a distinct appressorium. Up to this stage the behavior of the parasite was similar regardless of the nature of the host. In the compatible host-parasite combination, the parasite penetrated the host, established a nutritional relationship and continued to grow to cover the host completely with its buff colored spores in 3-4 days. In the incompatible host-parasite combination, the parasite penetrated the host but its further advance was arrested. As a result of failure to establish a nutritional relationship with the resistant host, the parasite made further attempts to penetrate the host at different sites producing multiple infections. In the absence of nutrition the parasite weakened and the host outgrew the parasite completely. In the presence of a non-host species, Linderina pennispora the parasite continued to grow across the non-host 1).yp_hae vlithout establishing an initial contact. Germination studies showed that the parasite germinated equally well in the presence of host and non-host species. Further electron microscope studies revealed that the host-parasite interaction between P. virginiana and its host, C. cucurbi tarum, was compatible when the host hyphae were young slender, with a thin cell wall of one layer. The parasite appeared to penetrate mechanically by pushing the host-cell wall inward. The host plasma membrane invaginated along the involuted cell wall. The older hyphae of C. cucurbitarum possessed two distinct layers of cell wall and-showed an incompatible interaction when challenged vlith the parasite. At the point of contact, the outer layer of the host-cell wall dissolved, probably by enzymatic digestion, and the inner layer became thickened and developed a papilla as a result of its response to the parasite. The haustoria of the parasite in the old hyphae were always surrounded by a thick, well developed sheath, whereas the haustoria of the same age in the young host mycelium were devoid of a sheath during early stages of infection. Instead, they were in direct contact with the host protoplast. The incompatible interaction between a resistant host, P. articulosus and the parasite showed similar results as with the old hyphae of C. cucurbitarum. The cell wall of P. articulosus appeared thick-with two or more layers even in the 18-22 h-old hyphae. No contact or interaction was established between the parasite and the non-host L. pennispora. The role of cell wall in the resistance mechanism is discussed.
    Collections
    M.Sc. Biological Sciences

    entitlement

     
    DSpace software (copyright © 2002 - 2022)  DuraSpace
    Quick Guide | Contact Us
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.