genes for grazing / harvesting wheat

Thu Aug 17 11:36:01 EDT 2006

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

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

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

Pankaj
[Plant Ontology]

PS: The mail is copied to plant ontology mailing list at 
po-dev at plantontology.org

Dave Matthews wrote:

> Hi Liuling,
> 
> Thanks for this information!  This is the most unusual use of wheat I'd
> ever heard of.  Grazing from November thru February, then growing for grain.
> 
> Hi Mark,
> 
> I'm sure you know about this use.  And you know a lot about phenology things
> like dormancy and probably vernalization.  Any thoughts?  (You did say you
> owe me a favor.  8)
> 
> 
> I'm especially curious about the "hollow stem" stage.  Google
> (http://www.google.com/search?q=wheat+hollow+stem) says this is a
> crucial thing for grazing/grain purposes in Oklahoma and Texas.  I don't know
> how the hollow stem relates to the initiation of reproduction.  Evidently
> this means there are stems produced in the vegetative stage but they aren't
> hollow.  
> 
> We're trying to organize the growth stages of cereals into a coherent
> database, the Plant Ontology.  This database has nothing about hollow stem
> in it yet.  The closest thing (I think) is "booting"
> http://www.gramene.org/db/ontology/search_term?id=GRO:0007090
> 
> 
> Hi Pankaj,
> 
> Can you please look into whether this is significantly different and if so
> how to include in the PO?
> 
> regards,
> - Dave
> 
> 
> 
> Date: Wed, 16 Aug 2006 19:18:25 -0500
> From: "Yan, Liuling" <liuling.yan at okstate.edu>
> 
> Hi Dave,
> 
> Please find my answers followed your questions. Just try to satisfy your 
> curiosity. Also please provide your suggestions if you have. Thank you.
> 
> ________________________________
> 
> From: Dave Matthews [mailto:matthews at greengenes.cit.cornell.edu]
> Sent: Tue 8/15/2006 8:22 PM
> To: Yan, Liuling
> Subject: re: Post for a PhD
> 
> Hi Liuling,
> 
> 
>>This advertisement says,
>>
>>  Wheat cultivars in the southern Great Plains are used for dual purpose
>>  production of forage and grain, which require a longer vegetative phase for
>>  grazing of livestock.
>>
>>Interesting.  I'd never heard of this.  When is the grazing?  Winter and
>>early spring? 
> 
> 
> We usually start to plant seeds from September, or as early as possible, 
> in order to have more vegetative tissues before winter, but it cannot be 
> earlier than September because of lack of rainfall.  Cattles are brought 
> to wheat field from November when plants have a lot of tissues to feed 
> the cattles. The cattles will be taken away from the field just before 
> 1st of March.
> 
> 
>>When is the reproductive phase desired to begin?
>>Is the reproductive phase called "booting"?  (Yes I've still got a lot to
>>learn about wheat.)
> 
> 
> A cretirion for the wheat development is that the first hollow stem 
> don't elongate before 1st of March; otherwise the cattles could eat the 
> wheat heads. Based on this cretirion, I am thinking that we should 
> select strong winter varieties that have more vernalization requiremnt 
> and do not entry "the reproductive phase" (or the first hollow stem 
> never elongate before 1st March). In other word, such varieties would 
> have a longer vegetative phase and produce more biomass for the cattles. 
> 
> 
> One of the objectives in my project will be to map genes that control 
> vernalization duration. Two parental lines (Jagger and 2174) for the CAP 
> population in Oklahoma have shown different vernalization requirements: 
> three weeks of vernalization significantly accelerating apex development 
> transition for Jagger and significant vernalization effects could be 
> observed only after six weeks of vernalization treatment for 2174.
> 
> Best regards
> 
> Liuling
> 
> 

-- 
Pankaj Jaiswal
G-15, Bradfield Hall
Dept. of Plant Breeding and Genetics
Cornell University
Ithaca, NY-14853, USA

Ph. +1-607-255-3103 / 4199
fax: +1-607-255-6683