Introductory Mycology, week IV: Phragmobasidia

[George Wong]

In article <9609201536.AA16475 at fmppr.fmnh.org>, jmurphy at TFM.FMNH.ORG 
says...
>
>Dear mycetophiles;
>   Most introductory mycology texts have these wonderful illustrations 
of
>the various types of phragmobasidia, and upon occasion I've been lucky
>enough to make good sections of Tremella and Dacrymyces and to see the 
real
>thing.  Auricularia, however, stumps me.  Does anyone have any 
suggestions
>for techniques for visualizing individual basidia of Auricularia for the
>light microscope?  The simpler the method,  the better - this is a 
teaching
>exercise and we don't have the wherewithal to use microtomes,
>freeze-fracture, or SEMs...
>
>thanks in advance,
>
>Jack 
>******************************************
>Dr. John (Jack) Murphy
>
>Dept. of Botany         Dept. of Botany
>The Field Museum                University of Wisconsin, Madison
>Chicago, IL 60605-2496  Madison, Wisconsin  53706-1381
>(312) 922-9410 ext. 722 (608)-262-8644
>fax (312) 427-2530              jfmurph1 at facstaff.wisc.edu
>
Dear Jack:

        Regarding your question on the Auricularia basidium, I'm afraid 
that Auricularia is not a good species to use for observing a 
transversely-septate phragmobasidium.  The basidia of Auricularia species 
are very compact and held together by a gelatinous matrix that will not 
allow observation of an individual basidium regardless of how hard you 
may smash down on the coverslip.  Even when you make sections that are 
only one to several cells thick, you would still not be able to visualize 
an entire, individual basidium since it's likely that your section will 
be somewhat oblique and adjacent basidia, on the same plane, would still 
be stuck together by the gelatinous matrix, making observation of 
phragmobasidial structures impossible.
        If you want your students to see an entire transversely-septate 
basidium of the Auriculariales, you should use one of the other genera in 
this order.  Helicogloea is probably the best genus to use.  
Unfortunately, it is one of those resupinate types which are extremely 
difficult to recognize in the field.  I've collected it, but only after 
hours of searching.  Even then more than 95% of my collections usually 
turn out to be resupinate homobasidiomycetes, with, if I'm lucky, only 
one or two specimens of Helicogloea.  You might try Eocronartium 
musicola.  This is a species that grows among mosses and superficially 
resembles an unbranched fruitbody of a coral fungus.  I've never looked 
at the basidium of this species, but at least it will be a species that 
you may be able to locate without too much trouble.  If you are able to 
try this species, let me know how it works. We don't have this species in 
Hawaii and I've never looked at it under the microscope prior to moving 
to here.
        I guess I wasn't much help with your problem.  Sorry.

Sincerely,

George J. Wong
Associate Professor
of Botany
Phone: (808) 956-3940
FAX:  (808) 956-3923
Email:  gwong at uhunix.hawaii.edu