[Fwd: RE: genes for grazing / harvesting wheat]

[Pankaj Jaiswal]

This a forwarded message from Yan Liuling with reference to a previous 
enquiry on hollow stem stage in winter wheat.

-Pankaj

-------- Original Message --------
Subject: 	RE: genes for grazing / harvesting wheat
Date: 	Sat, 19 Aug 2006 22:09:54 -0500
From: 	Yan, Liuling <liuling.yan at okstate.edu>
To: 	Pankaj Jaiswal <pj37 at cornell.edu>, Dave Matthews
<matthews at greengenes.cit.cornell.edu>
References: 	<200608170241.k7H2fHnv002436 at greengenes.cit.cornell.edu>
<44E48CE1.5060300 at cornell.edu>



Hi Pankaj (cc: Dave),

Thank you very much for so much information and elaboration on it. When
we talk about vernalization, we always use heading time or flowering
time as outcome of vernalization. But in this particular case I need to
use the elongation stage of the first hollow stem as a creterion . In
practice, all winter varieties have a similar flowering time, no matter
how much vernalization they require, but they have signifcant
differences in reaching the elongation stage of the first hollow stem
particularly in a warm winter season. Therefore differences in earlier
developmental stages should explain vernalization effects much better
than heading or flowering itme. In Oklahoma, when the lenght of the
first hollow stem is longer than 2cM, the stem is considered detectable,
which is a signal that cattles need to take away from the field.
Compared with Zadoks scale it should be 31. This is what I can explain
right now.

Thank you again and have a nice weekend.

Liuling


------------------------------------------------------------------------
From: Pankaj Jaiswal [mailto:pj37 at cornell.edu]
Sent: Thu 8/17/2006 10:36 AM
To: Dave Matthews; Yan, Liuling
Cc: Mark Sorrells; POC-dev
Subject: Re: genes for grazing / harvesting wheat

Hi Liuling and Dave,

According to the scales developed for Triticeae by Zadoks and Haun in
early 1970's  [Haun, J.R. 1973. Visual quantification of wheat
development. Agron. J. 65: 116-119.] and [Zadoks, J.C., T.T. Chang, and
C.F. Konzak. 1974. A decimal code for growth stages of cereals. Weed
Res. 14: 415-421.] and those mentioned on the site at
http://www.usask.ca/agriculture/plantsci/winter_cereals/Winter_wheat/CHAPT10/cvchpt10.php
the actual reproductive stage (the very initiation and differentiation
of the inflorescence starts way too early. Spikelet development on the
microscopic head is usually completed by the time the first node is 0.4
inches (1 cm) above the soil surface. The terminal spikelet is produced
at about Zadoks stage 31. A rapid loss of younger, poorly developed
tillers also normally starts at this stage
(http://www.usask.ca/agriculture/plantsci/winter_cereals/Winter_wheat/CHAPT10/cvchpt10.php#stem).

Probably the stage you are looking for the hollow stem is somewhat in
the range of Zadoks 15-18, Zadoks 34-36. These stages are overlapping.
This needs confirmation.

   The booting stage is very late in that sense because by that time the
boot is already swollen, the inflorescence is well developed and ready
to exsert out for heading stage. Therefore you will have to determine
the stages for a couple of the standard cultivars and germplasms in a
couple of growth conditions to see the variability. As far as I know
after this evaluation you will be able to predict the desired stage by
taking into account the genotype and environmental effects. You will
find similar studies by

McMaster GS, Wilhelm WW, Frank AB (2005) Developmental sequences for
simulating crop phenology for water-limiting conditions. Australian
Journal of Agricultural Research 56: 1277-1288

Skiw PEJ, Jame YW, Kryzanowski L (2001) Phenological development of
spring barley in a short-season growing area. Agron. J 93: 370-379

In all due respect you can use either of the Zadoks, Feekes or Haun
scales as well to map your stages.

Considering the Zadok scale 31 the corresponding stage defined by Plant
Ontology is SE.01 one node or internode visible [PO:0007091]
http://www.plantontology.org/amigo/go.cgi?view=details&show_associations=terms&search_constraint=terms&depth=0&query=PO:0007091 

<http://www.plantontology.org/amigo/go.cgi?view=details&show_associations=terms&search_constraint=terms&depth=0&query=PO:0007091>

For other Zadok scale search the Plant Ontology for terms using 'Zadok'.
The scale is listed as a synonym where ever applicable. e.g.
http://www.plantontology.org/amigo/go.cgi?session_id=7417b1155827789&page=2&view=query&search_constraint=terms&depth=&query=zadok&action=query 

<http://www.plantontology.org/amigo/go.cgi?session_id=7417b1155827789&page=2&view=query&search_constraint=terms&depth=&query=zadok&action=query>


Please let me know if you need more help. I will be happy to hear you
feedback.

Pankaj
[Plant Ontology]