At the beginning of class, we reviewed everyone's blog posts. Then we moved onto practicing how to identify fungi from culture. Several fungal cultures were available for microscopic glass slide mounts: Aspergillus niger, Pythium ultimum, Thielaviopsis bassicola, Altenaria brassicicola, and a Cladisporium sp. We used two different techniques, squash mounts and tape mounts, to visualize them under the compound microscope. A squash mount is used with a drop of water on the glass slide, a small section of the fungus from the agar plate and squashed with a glass cover slip. A tape mount was also used with a drop of water and a piece of tape to lift the fungal structures. The squash method was a better method in order to see the fungal structures, such as conidiophores, hyphae, and spores to aid in identification.
Aspergillus niger: Observed only pigmented single celled spores using the tape mount method. Observed septated hypae, condiophores, and spores using the squash mount. Tried several squash mounts to try to observe the phialides, but was unable to obtain a good mount.
Pythium ultimum: Observed coenocytic (lacking septa) hyphae, with sporangia characteristic of Pythium sp. Causes root rot on various hosts such as cool season grasses and ornamentals.
Thielaviopsis bassicola: Observed phialides conidiophores, and aleuriospores characteristic of Thielaviopsis sp. Causes a plant disease commonly referred to as black root rot.
Altenaria brassicicola: Observed pigmented conidiophores with chains of pigmented conidia with cross and longitudinal septa in chains. Septated hyphae. Can be a plant parasite, causing leaf spots and but can also be saprophytic.
Cladisporium sp: Observed pigmented, dark conidiophores with one and two celled conidia some in chains. Can be plant parasitic on plants such as spinach causing leaf spots. Can also be saprophytic.
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| Hemacytometer |
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| Square grids of hemacytometer as seen under the compound microscope. |
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