Hi Ross,
There are surprisingly few data on biomass production of Arabidopsis. In our
paper "Maximal biomass of Arabidopsis thaliana using a simple,
low-maintenance hydroponic method and favorable environmental conditions" in
Plant Physiol (1997) 115:317-319 we compare our biomass production to
others. Compared to other published reports our plants are 10 to 100 times
larger in dry weight. A lot of this has to do with daylength and
environmental conditions, but I believe it also has to with soil conditions.
Most people grow them with a very restricted root system. If you check my
hydroponics paper on the web, it has an additional figure not included in
the one cited above. From that photo you can see how massive the root system
can get if allowed to grow in an unrestricted environment. It also has a
link to where you can get rockwool.
I advise you to look at our article and photos on the web to decide if
your plants are abnormal. Personally I don't think most people concern
themselves with optimal conditions and therefore by default do not grow very
good Arabidopsis. On the other hand it may not be that important for most
people. I, however, am very interested in growth and plant stress. Stress is
defined as anything less than optimal.
I do not know of any toxicity concerns regarding rockwool. I simply
dispose of it in the trash. Please let me know if you find out that there
are problems with it.
All the best,
Grant
--
Grant R. Cramer
Associate Professor
Mail Stop 200
Department of Biochemistry
University of Nevada
Reno, NV 89557
phone: (775) 784-4204
fax: (775) 784-1650
email: cramer at med.unr.edu
web page: http://BIOCHEM.MED.UNR.EDU/faculty/grant_c/
----------
>From: Ross Koning <koning at ecsuc.ctstateu.edu>
>To: cramer at unr.edu ("Grant R. Cramer"), plant-ed at net.bio.net>Subject: Re: Growing Arabidopsis?
>Date: Mon, Aug 2, 1999, 9:07 AM
>
> Hi Grant!
>> One point I failed to make in my previous post was that
> I also remind students to handle the phytagel block
> directly rather than lift the phytgel block by pulling
> on the seedling.
>> I haven't tried rockwool yet so I'm not clear about
> growth rates and final size. The phytagel move to
> Fafard #2 for us has resulted in plants about 30-40
> centimeters (to top of inflorescence) and with perhaps
> 25 basal rosette leaves. I don't know whether that is
> "puny" or not...but I have been happy with the size
> and growth rate. We grow under lights and this size is
> almost too-big as it is (inflorescences getting crowded
> and possible cross-pollinations). So, if that IS puny
> and your method gives significantly larger plants, I'm
> not sure it would help in our situation. Please advise
> on this as it is important to know whether our plants
> are indeed abnormal or not. If I can get my hands on some
> rockwook I'll give it a try to see if I like it better.
>> I do have one other question, though, and that is safety.
> With the asbestos problem, and with parallel fiberglass
> legislation "in the works", dare we use rockwool in
> teaching? I have become quite concerned even with using
> perlite...I do use it, but have the students wet it down
> immediately to avoid its dust. And, when you are done
> with rockwool, is there any problem with disposal?
> Currently I put our greenhouse waste in my home compost
> pile (since the ECSU greenhouse is pesticide-free), but
> I think I would put rockwool in our university trash-stream.
> I'm wondering if trash contractors would have a problem
> with it mixed in with the rest of the trash.
>> ross
>> At 10:52 AM -0400 8/2/99, Grant R. Cramer wrote:
>>Ross,
>>We have tried this method as well (and about 200 others!). There are two
>>problems with this technique: One, although the roots grow in phytagel and
>>agar, they grow much more slowly than in rockwool. I suspect that aeration
>>is inadequate. Plants are downright puny when grown by this method. And two,
>>there is a big problem with transplant shock (as you pointed out), even if
>>you include the gel (because it is quite soft and floppy). These seedlings
>>are tiny and very delicate. With rockwool, you won't have aeration problems
>>and if you must transplant, you can plant in a large enough cube and the
>>material is firm enough that you can transplant without shocking the plant.
>>--
>>Grant R. Cramer
>>Associate Professor
>>Mail Stop 200
>>Department of Biochemistry
>>University of Nevada
>>Reno, NV 89557
>>phone: (775) 784-4204
>>fax: (775) 784-1650
>>email: cramer at med.unr.edu>>web page: http://BIOCHEM.MED.UNR.EDU/faculty/grant_c/>>>>----------
>>>From: koning at ecsuc.ctstateu.edu (Ross Koning)
>>>To: plant-ed at net.bio.net>>>Subject: Re: Growing Arabidopsis?
>>>Date: Sun, Aug 1, 1999, 2:21 PM
>>>>>>>> Getting the seeds to sprout on a simple mineral-
>>> phytagel plate is easy (I have used MS salts and
>>> Knopps with equal success). The problem comes when
>>> students try to move them to soil. The young seedlings
>>> can take NO root-abuse in that stage. The problem here
>>> was solved by letting the students move each seedling
>>> with the phytagel INTACT...carving out a block that
>>> included the root and planting the whole block. Once
>>> I figured that out, all my students had success with
>>> their "mystery mutant" arabidopsis plants. To get the
>>> seeds sown in the plates thinly enough I found that
>>> a SMALL quantity of seeds in a microfuge tube are held
>>> well on the walls of the tube by static electricity
>>> (or other forces). This allows the student to tap
>>> on the tube to release just one seed at a time and
>>> get them spaced apart widely in the dish so that
>>> root damage can be minimized at the transplant time.
>>>>>> ross
>> ________________________________________________________________
> Ross Koning | koning at ecsu.ctstateu.edu> Biology Department | http://koning.ecsu.ctstateu.edu/> Eastern CT State University | phone: 860-465-5327
> Willimantic, CT 06226 USA | fax: 860-465-4479
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