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. Ill give a short legend on these to explain a little but I cant 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)
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)
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
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.