Daily Account #8

5/10- today was learning about fungi continued, this time with Noelle.

fungi can be anywhere from commensal to parasitic (all fall somewhere on that scale). we learned about several different kinds of fungal relationships:

1) fungus + root = mycorrhiza, whereby fungi takes carbon from the root of the plant and helps to transfer water and minerals in turn.

2) lichens = a fungus + a green alga or a cyanobacteria
they get wet and absorb pollutants, especially sulfur gases. that's why they are sparsely populated in urban areas with pollution.
there might be about 15-20 species of lichens on campus- you would find these to be more resistant to pollution than the kinds you would find in the forest.

3) hollyhock rust (Puccinia malvacearum) is a plant parasite. this fungi will not kill its host plant, can be very orange in color, the spores reinfect the plant that it is on (commonly hollyhock), and the hollyhock plant we looked at near the UW Farm also had white flies on the bottom.

4) powdery mildews are also plant parasites. they are very opportunistic- so they might appear when a plant is already weak or vulnerable. they go into cells and absorb the nutrients from living cells. the white color you see are hyphae. the mildew is just piles of spores that can break off easily (from wind, etc) and travel around- they are probably asexual spores.

we learned that birch trees must have micorrhyzal fungi, as do most wild trees. ectomycorrhiza means that it is outside of the root, while endomycorrhiza means that it is inside of the root. ecto- actually reshapes the root itself, to make it more short and stubby, which we saw on the roots of baby birch trees.

an interesting fact we learned was that if you fertilize a plant really well, they can kick their mycorrhizae out, because they're getting all their necessary nutrients.

mycorrhizae produce mushrooms to reproduce, like porcini, chanterelle, etc.

we spent the last few minutes talking about lichen- whose morphology can change in polluted areas. in other words, what you find in the city will look different from what you find in the forest, even if the species is the same.

they can grow on rock and other surfaces that are hard for others to grow on, as well as grow in harsh conditions. they are a primary successional species.

species list:
Puccinia malvacearum
powdery mildew diseases are caused by many different species of fungi in the order Erysiphales

Posted on May 19, 2012 08:51 PM by akumar