Subject: papulospores

From: [email-masked] (John (Jack) Murphy)
Date: 4 Nov 1996 07:42:04 -0800

Dear fellow mycophiles;
    Personalities aside, I am interested in the recent discussions
concerning the perithecium/pycnidium, cleistothecium/papulospore.
    As I understand it, both Basidiomycetes and Ascomycetes can from sexual
cells naked on a mycelium (e.g., Exobasidium and Taphrina).  There is a
form-order of Deuteromycetes which do the same with conidiophores - the
Moniliales.  Perithecia are flask-shaped structures containing asci;
pycnidia are flask-shaped structures containing conidiophores.
Functionally, these structures seem equivalent (whether they are homologous
or analogous I can't say, but I'd hypothesize the former).
       The introductory Mycology text by Alexopoulos, Mims and Blackwell
has no reference to conidiomata which resemble cleistothecia, which are
closed ascocarps containing asci.
    Ms. Collins suggests that the papulospore serves this function; i.e.,
it is a closed structure which contains conidia.  Ainsworth and Bisby
(1983) define the papulospore as a small rounded propagule comprising one
or more enlarged central cells surrounded by a sheath of smaller cells.
The question remains (for me, anyway), do these central cells act as
conidia?  If so, then functionally a papulospore is similar to a
cleistothecium.  I haven't browsed the library, but perhaps a reader with
experience with papulspores could comment.
   By the way, the reference to anal-retentiveness is not without
precedence in Mycology.  The interested reader might see Petersen (1976)
"Species concept in higher Basidiomycetes: taxonomy, biology, and
nomenclature." Herbette Symposium on species concept in Hymenomycetes.  Pp.
363-380.

sincerely,

Jack

*****************************************************

John (Jack) Murphy
Dept. of Botany, The Field Museum
Roosevelt Road at Lake Shore Drive
Chicago, IL   60605
(312) 241-6519

Please also crosspost email messages to  [email-masked] until
Dec. 20, 1996.

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From: David Geiser <[email-masked]>
Date: 4 Nov 1996 17:22:53 GMT

In article <v02140b02aea2779e4b7c@[192.107.185.53]> John,
[email-masked] writes:

>Ainsworth and Bisby
>cleistothecium.

If the cells act as dispersed propagules,  then I agree that it
would indicate a degree of functional similarity.  Enough to call
them analagous?  I guess so.

Another question is the phylogenetic placement of Papulaspora.  If
it's aligned with the Plectomycetes,  then is it reasonable to
suspect that the papulaspore is a modified cleistothecium?  If
it is,  then I think we're back in the realm of homology.  I
don't know of any molecular or other data on the subject.  The
AInsworth and Bisby definition sounds like a young cleistothecium
to me.

>precedence in Mycology.

Wait a minute - is the term hyphenated?  :-)

Dave Geiser,  unabashed anal-retentive

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From: Kelly Patrice Collins <[email-masked]>
Date: 6 Nov 1996 16:27:40 GMT

David Geiser <[email-masked]> wrote:

>them analagous?  I guess so.

Yes, but are they indeed to disperse propagules or are they sclerotia of 
some sort?  I am unsure and, thus far, so is the literature.

>AInsworth and Bisby definition sounds like a young cleistothecium

But the cells within do not go on to form anything that at all resembles 
spores, so I am brought back to the above question.

>Wait a minute - is the term hyphenated?  :-)

Yikes!!!  I am sorry I said that.  I did not mean for anyone to take 
offense.  I just thought it was funny that I was being called on the 
exact meaning of a term for something no one seems to know exactly what 
to call.

Sincerely, Kelly

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From: Peter Herman <[email-masked]>
Date: 6 Nov 1996 18:32:57 GMT

>AInsworth and Bisby definition sounds like a young cleistothecium

If the structure is asexual, there is no reason to suspect a 
modified cleistothecium.  The problem with sorting things out is 
the relative simplicity of fungal thalli.  If a fungus is 
producing a thick-walled resistant structure, be it sexual or 
asexual, there are a limited number of patterns it can follow to 
make such a structure from hyphae.  When you look at the cell 
arrangements and modifications involved in cleistothecia, 
parathecia, apothecia, pseudothecia, pycnidia, sclerotia and 
stromatic tissues, they can look quite similar, though the 
structures can vary a lot in gross appearance.

Peter

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From: David Geiser <[email-masked]>
Date: 8 Nov 1996 00:30:18 GMT

>some sort?  I am unsure and, thus far, so is the literature.

Then I really question their functional similarity.  In fact,
the more I think about it,  the more trouble I have with the idea
of calling any sort of asexual structure analagous to a cleisto-
thecium.  There are certainly some adaptations related specifically
to sex,  and a sclerotium-type thing isn't going to fulfill them
all.
 
>spores, so I am brought back to the above question.

Me too.  Homologous maybe,  analagous,  I don't think so.

>offense.

None was taken.  In fact,  I appreciate your bringing up an interesting
topic of discussion.

Dave Geiser

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From: [email-masked] (Eric Robb Siegel)
Date: 8 Nov 1996 11:20:58 -0800

On 8 Nov 1996, in response to Kelly Patrice Collins, David Geiser wrote, 

> to sex,  and a sclerotium-type thing isn't going to fulfill them

Yeah, but isn't it true that some species of Aspergillus were long 
recognized as making sclerotium-type things, and it was not until someone 
opened up one of those developing sclerotium-type things and found asci 
that they realized that those sclerotium-type things were cleistothecia?

For that matter, if propagule dispersal is a criterion, how does being 
locked up inside a cleistothecium aid dispersal?

Is there any chance that what Kelly has are real cleistothecia, not just 
"analogous structures"? 

Eric Siegel

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From: David Geiser <[email-masked]>
Date: 9 Nov 1996 17:23:43 GMT

In article <[email-masked]> Peter Herman, [email-masked]
writes:

>modified cleistothecium.

I really don't know if it's reasonable to suspect that a papulaspore
is derived from a cleistothecium.   However,  I do think it's
reasonable to suspect that certain asexual structures are.  Two
examples from the Trichocomataceae:  Aspergillus flavus,  which
produces sclerotia,  seems to be related to Petromyces alliaceus
(see Peterson,  S.W., 1995 Mycol. Res. 11: 1349-1355), which produces
cleistothecia in stroma that look quite like the sclerotia found in 
A. flavus and its relatives.  In fact,  P. alliaceus was first
described as sclerotial,  until Malloch and Cain (1972;  Can. J.
Bot. 50: 2613-28) found ascospores;  in describing Eupenicillium
and its asexual relatives,  Pitt (1979;  The Genus Penicillium,
pp. 41) mentions that some asexual species produce immature
cleistothecia that don't go on to produce ascospores,  and that
these structures are termed sclerotia.

Perhaps I'm making too big a deal of these examples from this
group,  but my point was that if Papulaspora is related to
cleistothecial ascomycetes,  it may be that the papulaspore
is a modified or vestigial cleistothecium.  Again,  I don't
know enough about Papulaspora to say whether or not this is
reasonable.

  The problem with sorting things out is 
>structures can vary a lot in gross appearance.

Yes,  and this is why I think molecular phylogenetic analyses
are helpful in sorting out these difficult morphological questions.
That said,  it's amazing to me how well the morphologists have done 
inferring relationships,  considering how little they have to work 
with.

Dave Geiser

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From: [email-masked] (Kathie T. Hodge)
Date: Tue, 12 Nov 1996 16:11:05 -0400

OK, here's one for you:

Mathieson described a strange thing which he proposed fairly convincingly
to be an anamorph of Cordyceps aphodii Mathieson.  It is like a
cleistothecium in that it produces phialoconidia inside a small ball of
branching, modified hyphae which grow up and around the conidiophore from
the subtending cell.  It looks vaguely like an Aegerita that's filling
itself up with phialoconidia inside.

I just encountered the thing in the literature this weekend, and I would
be very interested to hear from anyone who's actually seen it or has a
culture of it, or who can think of a genus it might fit into.  It's quite
astounding.

Mathieson describes it as "Conidial Stage A" in the following paper:
Mathieson, J. 1949. Cordyceps aphodii, a new species, on pasture
cockchafer grubs. Trans. Brit. Mycol. Soc. 32(2):113-136.

Kathie Hodge
[email-masked]