5/10/12 Relationships with Fungi; Lichen

Today we discussed the role that fungi plays in the existence and survival of other species. The main species we focused on was lichen. Lichen is formed by the mutualistic relationship between fungus and other alga or cyanobacterium. Fungus provides water and breaks down cell components to readily provide carbon while the alga/ cyanobacterium fix nitrogen and provide the fungal component of lichen with necessary nutrients. Two other resulting species groups from fungal relationships are HollyHock Rusts, which are plant parasites, and Powdery Mildews; both of these are biotrophs.
Out in the field we observed these fungal relationships by analyzing plant root color and shape to determine whether or not these plants had a fungal infection. We observed a powdery mildew on a maple and learned that this occurs when spores fall on the leaves of a maple and germinate. We then observed HollyHock rust, which is a bright orange/brown color and attacks HollyHock. Every small dot of rust starts out orange and turns brown. This is how you can determine whether or not the rust is new. HollyHock is a parasite and so it reproduces asexually. There is also Wheat Rust, which attacks wheat and grass and it is also a parasite.
Lastly, we observed numerous species of lichen such as Melaniella, which is a dark lichen, crustose lichen, Usnea, Xanthoria pollycarpa, which is a yellow lichen, and hypnogymnia physodes.
This day was particularly helpful for me due to the fact that my group project is focused on lichen. It was incredibly important to understand the intricacies in identifying lichen as well as the mutualistic relationship between fungus and alga/cyanobacterium that composes it.

Species List:
Melaniella
Crustise lichen
Usnea
Xanthoria polycarpa
Hypnogymnia physodes
HollyHock Rust
Powdery Mildew
Evernia prunastri

Posted on June 3, 2012 02:05 AM by laurars13