Activitiy 1: Examination of fungal morphology

Activity 1: Examination of fungal morphology

 

Equipment/Materials

 

Transmission light microscope

Dissecting scope

Microscope slides and cover slips

Dropper bottles of H2O, Meltzer's.

razor blades

forceps

emersion oil

various fungal fruiting bodies

 

Macroscopic analysis of fungal fruiting bodies

For this part of the activity, we will look at different fungal fruiting bodies and observe their anatomical features.  This exercise will help you to categorize, and ultimately identify the various classes of fungi.

 

Exercise 1) Pick up a mushroom from around the classroom, and answer these simple questions.

            a.  What shape is the fungus?

            b.  Where are the spores produced on the fruiting body? (exposed, enclosed…)

            c.  Does the fungus have gills, pores, or none of the above?

d.  Where was the fungus growing?  (above/below ground, on the ground, on a tree, on wood, on soil, in grass, on dung…)

e. Are the tissues of the fruiting body soft (perceived easily chewable) or hard (like wood)?

 

Rudimentary questions such as these will help you categorize the type of fungus you are dealing with and allow you to further identify your fungus.  With these questions you should be able to determine whether your fungus is a…

 

Basidiomycete, Ascomycete or Zygomycete

Agaric, polypore, gasteromycete, coral fungi, etc…

Deduce whether the fungi is mycorrhizal, saprotrophic or possibly parasitic.

Has monomitic or polymitic tissues.

 

•Phylum of fungi



Zygomycota

Bread Molds

Includes: Rhizopus

and Pilobolus


Ascomycota

Includes: yeasts, Penicillin, Sordaria

cup fungi i.e. Morels


Basidiomycota

Most diverse of the macro fungi. Includes: Mushrooms, Boletes, Polypores, Puffballs, Jelly fungi, Rusts and smuts.

 

 


Exercise 2) Now try making a more precise identification of your fungus.

 

The following characteristics can help you identify Basidiomycetes

Parts:   •Spore color - spore print (Agarics and other Basidiomycetes)

•Pileus (cap)- Size, Shape, surface features, color, trama tissue, color

•Spore bearing layer - enclosed/exposed, smooth/lamellar (gilled) /poroid,

• For lamellar fungi - size, connection to stipe, number, Lamellulae, color, deliquescing.

•Stipe (stem) - presence/absence, length/diameter, connection to pileus (central/lateral), presence of an annulus or volva.

 

Flip through some of the identification guides in class to see if you can identify your fungus to a family, or genus.

 

 

Microscopic analysis of a Mushroom

For this activity you will learn how to look for the various microscopic features of a mushroom.  These are some of the more important features when trying to identify the higher fungi. Some of these features include:

 

•Spores - color, shape, features, chemical reaction

•Hymenophore (spore producing) surface - basidia or asci

•Lamellae - surface (hymenophore), trama, edge

            •Pileus - surface, trama, hyphae

            •Stipe - surface, trama

 

 

The diagram to the left represents

various anatomical features of a mushroom.

FILL IN THE BLANKS.

 

 

Exercise 3) Spore observation under a microscope. - Using your forceps, tear of a small piece of lamellae (gill) from the fungi and mount in water.  Do this again in Meltzer's Reagent.

-Add cover slip

-Gently squish the tissue under the cover slip with an eraser

-Follow these steps when mounting slides onto the microscope

1) Lower microscope stage completely and set objective lens to lowest power. 2) Carefully add the slide to the stage making sure not to snap the arm of the slide holder (this can crack or even shatter the slide).

-While observing with the lowest magnification, bring the slide into focus, and center the slide on the area of interest (usually the edge of the tissue).

-Increase the magnification to the next objective lens and follow the previous set of instructions. Spores should have been released from the squash and should be suspended in the medium between the slide and the cover slip.  Look for many floating objects that are uniform in size and shape.  Typically rounded overall.  These should be the spores.

-Compare the spores in both water and Meltzer's reagent.  Besides the color difference between the two solutions, is there any other difference you can identify?

-Describe the spores below with as many descriptive terms as possible.  Include an illustration.

 

 

 

 

 

 

 

 

 


Define these terms:

 

Hyaline -

 

Amyloid -

 

Dextrinoid -