Problems with growing healthy Arabidopsis plants - light intesity?

Dr. Kuzma,

It sounds as though your difficulty in the walk-in chamber may result from too much or too little light intensity. I am not a scientist, but we hear of this problem occasionally. I am guessing that in your reach-ins, the plants are only 8-10" away from your lamps and much further in the walk-in chamber. If both are truly set at 200 microeinsteins, this is usually measured at 6" from the lamps and the intensity diminishes further away. Alternatively, your walk-in may be equipped with much higher light intensity and be providing too much light. Try measuring your light intensities in all chambers with an independent meter and comparing the levels.

Best Regards,
Karl Lundy
Sales Manager
Percival Scientific, Inc.
800-695-2743 ext. 36

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Today's Topics:

1. problems with growing healthy Arabidopsis plants (Monika Kuzma)
2. Bioinormatics courses - Montreal, Edmonton (Brian Fristensky)


----------------------------------------------------------------------

Message: 1
Date: Tue, 6 Feb 2007 15:47:22 -0500
From: "Monika Kuzma" <[Only registered users see links. ]>
Subject: [Arabidopsis] problems with growing healthy Arabidopsis
plants
To: <[Only registered users see links. ].indiana.edu>
Message-ID: <000901c74a30$00826660$[Only registered users see links. ]>
Content-Type: text/plain; charset="iso-8859-1"

Hello

I'm writing to see if anyone has come across these types of problems with
growing of Arabidopsis plants and knows the reasons for these problems.



We grow Arabidopsis plants in two ways. For some experiments they are grown
in trays with 36 slots filled with soil-less mixes such as Pro-mix (Plant
Products) or Sunshine mix (JVK). For other experiments plants are grown in
individual pots ranging in size from 2.25" to 4". Plants in trays are
usually grown in reach-in two shelf growth chambers (MTR30, Conviron) and
plants in individual pots are grown in walk-in chambers (PGV36, Conviron).
All chamber have the same growth conditions of 22C, 50-70% RH, 18hr light
(150-200 uE) and 6hr dark. Plants are watered with RO water daily from the
top as needed, trying not to over-water and allowing soil to dry up a little
between waterings, especially when the plants get a little bigger . All
plants are fertilized twice weekly with 20-20-20 (plant products) (1g/L)
solution starting at about 1 week after transplant. All plants are started
on ½ MS agar plates for 1 week before transplanting into soil media.



Only in plants that are grown in the walk-in chambers (in individual pots
rather than trays) we see the following 2 problems:



1). During vegetative growth at about 4-5 leaf stage the main meristem dies
off, senesces and stops further production of leaves. These plants do not
bolt or continue to grow.



2) Plants grow nicely until bolting time. At bolting the main stem
produces sick abnormal flower. The buds are very small and open into tiny
flowers which become aborted and do not result in no healthy pod production.
Sometimes, healthy flowers and pods will form after a series of abnormal
flowers and sometimes not.



These two problems can happen independently or in the same experiment.



We have noticed these problems on and off over the last few years.
Generally, more so in the winter than in the summer. We have attributed
them to problems with soil because changing our soil mix from Promix to
Sunshine or vice versa would generally get rid of the problem. Recently,
however both soil mixes give us these problems. The puzzling thing is that
plants grown in trays in the smaller reach-in chambers do not show any of
these problems and the same soil media are being used.



I would welcome any suggestions or ideas on what may be at the root of the
problems



Monika Kuzma







Dr. Monika Kuzma

Manager, Gene and Trait Assessment



Performance Plants Inc.,

4th Floor, BioScience Complex,

116 Barrie Street, Suite 4600

Kingston, ON K7L 3N6

Telephone: (613) 545-0390 EXT. 18

Facsimile: (613) 545-3618

Email: [Only registered users see links. ]

Web: [Only registered users see links. ]



the promise of growth



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------------------------------

Message: 2
Date: Tue, 06 Feb 2007 17:24:13 -0600
From: Brian Fristensky <[Only registered users see links. ]>
Subject: [Arabidopsis] Bioinormatics courses - Montreal, Edmonton
To: [Only registered users see links. ]
Message-ID: <[Only registered users see links. ].umanitoba.ca>
Content-Type: text/plain


AUDIENCE: Bioinformatics Researchers and Students
The Genome Canada Bioinformatics Platform
The Applied Computational Genomics Course (ACGC)

Join the ACGC for one of two weeks -- April 13-19, 2007 at McGill University
in Montreal, Quebec OR July 25-31, 2007 at University of Alberta in
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The Bioinformatics Platform designed the ACGC to empower bioinformatics
researchers and students by teaching a hands-on course, that outlines
tried-and-proven approaches as well as new developments.

For more information visit the website:
[Only registered users see links. ]

or email [Only registered users see links. ] (Subject: ACGC Inquiry)

__________________________________________________ ______________________________
The project is supported by Genome Alberta and Genome Canada, a not-for-profit
organization which is leading Canada's national strategy on genomics with
$ 600 million in funding from the federal government.

Brian Fristensky
Department of Plant Science
University of Manitoba
Winnipeg, MB R3T 2N2 CANADA
[Only registered users see links. ]
Phone: 204-474-6085
FAX: 204-474-7528
[Only registered users see links. ]
================================================== ==

Bill Gates is powerful, but he isn't God. If he was,
Windows would show evidence of Intelligent Design.

================================================== ==



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