Fw: Wheat anatomy (fwd)

Thu Dec 9 13:37:22 EST 2004

Hi POC colleagues,

Following Chapman & Peat ("An Introduction to the Grasses - including
bamboos and cereals", 1992; CAB International; ISBN: 0851988032) the
pulvinus in some members of the Poaceae does not appear to be homologous
with the pulvinus in eudicots. To quote from Chapman & Peat, p.10  under
the subtitle of "Stems" - "The nodes are usually visible as slight
swellings of the stem, but in some cases, notably tropical species the
node may be so enlarged as to form a pulvinus." Two photos are provided
- the one showing a conventional node of Bromus sterilis & the other the
swollen pulvinus of Digitaria exilis. In eudicots the pulvinus appears
to be explicitly associated with the proximal end of the petiole or
petiolule while in the Poaceae I'm unclear whether the pulvinus is
entirely formed by the nodal tissue of the culm or by both the nodal
tissue of the culm and the base of the leaf sheath or just the latter
(...another research opportunity!). 

Is this leading us to another 'sensu Poaceae' term? - Hmmm - perhaps
this is unavoidable at present. The needed definition must make a clear
distinction between the two terms.

- Leszek
*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*
P. Leszek D. Vincent Ph.D., FLS
Plant Science Unit
Res. Prof. Dept. of Horticulture
215 Curtis Hall
University of Missouri-Columbia
Columbia
MO 65211-7020
USA
Ph: (573) 884-3716; Fax:(573) 884-7850;
Email: Leszek at missouri.edu
Associate Curator, Dunn-Palmer Herbarium (UMO);
Research Associate, Missouri Botanical Garden (MO), USA;
Plant Systematist on The Plant Ontology Consortium - NSF award 0321666
*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=* 

________________________________

	From: owner-po-dev at brie4.cshl.org
[mailto:owner-po-dev at brie4.cshl.org] On Behalf Of Kellogg, Elizabeth A.
	Sent: Wednesday, December 08, 2004 3:36 PM
	To: po-dev at plantontology.org; Pankaj Jaiswal
	Subject: RE: Fw: Wheat anatomy (fwd)

	I'm not convinced of the identity between the pulvinus as the
term is applied in eudicots and term applied in wheat.  I looked at a
couple of the references that Pankaj sent,and don't quite see what the
structure is that they are referring to as pulvinus - it looks like a
part of the internode to me, but maybe it's because I can't easily see
the details of the photos.  
	   The apex of the ovary in all Triticeae is covered with
macrohairs, and these persist in the fruit.  I guess this is what is
called the brush.  I don't think I've ever heard the term "bristle"
applied to those hairs.
	Toby

		-----Original Message----- 
		From: owner-po-dev at brie4.cshl.org on behalf of Pankaj
Jaiswal 
		Sent: Wed 12/8/2004 2:11 PM 
		To: po-dev at plantontology.org; Victoria 
		Cc: 
		Subject: Re: Fw: Wheat anatomy (fwd)

		Katica Ilic wrote:

		> Hi Victoria,
		>
		> I looked through your list shortly after I received
it, just didn't
		> have time to reply. As I mentioned in my earlier
e-mail, most of the terms
		> (39 terms exactly) are already in the PO. Remaining
three terms are not in the PO,
		> and one sould be introduced, term pulvinus, to which I
provided definition
		> from K Esau.
		>
		> New term: pulvinus
		>
		> Definition: An enlargement of the petiole of a leaf,
or petiolule of a
		> leaflet, at its base. A structure that has a role in
the movements of a
		> leaf
		> or leaflet. (def from K Esau).
		>
		> I need to see where exactly this term would go into
Plant Structure
		> Ontology.
		>

		By your definition, it is the swollen part of the
petiole. Whereas in
		cereal crops, the leaf does not have a petiole. All they
have is a leaf
		sheath and leaf lamina.  However sheath can be regarded
as a structural
		homolog of petiole. I guess the wheat people are calling
is a different
		structure found at the base of the leaf sheath and the
structure seems
		to play a role in gravitropism.. I looked at fig-1 of
the following
		reference
		http://archiv.fgk.org/01/BLT/dispersion/

		Kaufman et al
http://www.jstor.org/view/00029122/di001875/00p0367d/0 are
		calling it "Leaf sheath pulvinus".

		Looks like it can have the following lineage in ontology

		leaf
		..[p] petiole
		......[p] pulvinus (PO:new term)
		..........[i] leaf sheath pulvinus (PO:new term)
		..[p] leaf sheath
		......[i] leaf sheath pulvinus (PO:new term)

		More refs:
		http://jxb.oupjournals.org/cgi/content/full/52/358/1029

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&lis
t_uids=11537463&dopt=Abstract

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&lis
t_uids=8490136&dopt=Abstract

		> The last two are terms 'crease' and term 'beard'. I
need to find out if
		> they can be synonyms of the existing terms.
		>

		If I am not wrong, the "beard" is a synonym for "awn".

		"crease is a particular type of morphological character
found in grains
		of Triticeae. I suggest creating a new term.

		Suggested lineage in PO
		        Seed
		        ..[p]..crease
		definition: the indentation on the ventral side of the
seed as found in
		the members of Triticeae

		I found one more term "brush" under "seed"
		It is often called as bristle, but in order to avoid
having confusion
		between bristle leaf and bristles found on seed, my
suggestion is to
		call it "seed bristle"

		seed bristle: fine hairs on the distal end of the seed
as found in the
		members of Triticeae

		        Seed
		        ..[p]..seed bristle (synonym: brush)

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