Some Photomicrographs for Teaching Stuff

I got a request from a photo editor for a number of illustrations of fungi for a  teaching CD on biological diversity.  I had occasion, therefore, to sort through a number of slides for illustrations that might be useful or interesting to biology students.  Of course, I  generally take the position that ANYTHING on fungi is interesting if it is presented in the right way. Mind you, it always helps  if you have decent slides to help to make your points.  

I eventually sent the photo editor over a hundred illustrations , mostly of microfungi, from which to make his selection. They were sent electronically as JPEGs.   So it was cheap, quick and easy for him to bring them up on his computer for evaluation.   We're spoiled!  In the old days I would have sent custom copy slides or originals  by courier (expensive) and worried about them until they were returned (stress).  And I certainly wouldn't have sent a hundred of my best slides in the mail.

At any rate, this month I have included several of the illustrations  I sent off.   I’ll give a short legend on these to explain a little but I can’t give the whole story as it takes too much time and space.    I may add other illustrations from this selection from time to time  in the months that follow.    Or not!

1. Amoebophilus   (= amoeba lover)     Division Zygomycota

Amoebophilus simplex (click here) amoebo1.jpg (7205 bytes)      

        

I discovered this fungus a number of years ago by accident while looking for parasites of rotifers which were my consuming interest at the time.  It turned out to be not only interesting and unusual but the fungus had never been described before.  

2.  Uncinula necator  causes powdery mildew of grapes.  Division Ascomycota

Ascoma (cleistothecium) of Uncinula necator   click here)   uncinu2.jpg (50440 bytes)                                                                              

If you are a gardener you will find that a number of your ornamentals and even your lawn grass will be attacked by powdery mildews. There are tens of thousands of species of higher plants attacked by the powdery mildew group. These diseases are is so-named as the fungi produce a white powdery growth on affected plants. Leaves will become malformed and distorted and the plants are very unattractive and might even die. Phlox, Zinnia, Lilac, Roses, Forget-Me-Nots, are only a few of the many ornamentals attacked. The white powder is the ‘dispersal spore’ stage that spreads the disease from leaf to leaf and to other plants of the same species. As well, in later stages you see tiny dark dots, less than 0.5 mm across, amongst the white powder. This is the ascoma sexual stage (cleistothecium) that allows the fungus to persist over hard times (winter cold, summer heat etc.).  Surprisingly under the microscope this stage in powdery mildews can be quite attractive

  This is a commercially important disease causing economic losses.

3. Arthrobotrys oligospora             Division Deuteromycota                                                                             

       wpe41F.jpg (27819 bytes)                                                                                      

Fungi attack a great variety of other microorganisms.   Amongst the microorganisms attacked are nematodes, sometimes called roundworms.  Nematodes are not segmented and are not related to annelid worms.   They vary in length from  about 100 microns to several millimetres. 

Some fungi have developed remarkable ways of capturing and killing nematodes.  The Constricting Ring (Special of the Month Nov 99) and the Haptoglossa Gun Cell (Special  of the Month July 2000) are examples of sophisticated methods of attack and exploitation.   The Adhesive Network of Arthrobotrys oligospora  is one of the most common and successful of the devices used by fungi to capture nematodes.