At 3:40 PM -0400 5/2/97, Jon Monroe wrote:
>Plant-edders,
>>I'm forwarding this message from Haima Rowena J. Lucas that just appeared
>on the biolab list. Please reply to Haima. Thanks, Jon Monroe
>(monroejd at jmu.edu)
>>>>Hello everyone!
>>>>I am looking for laboratory experiments used to teach concepts on plant
>>life and processes that UTILIZES MUNGBEANS (or any of its
>>"relatives"--Leguminosae)
>>>>This is connection with my research at the Laboratory of Science
>>Education, Hiroshima University, Japan.
>>>>I would really appreciate any information.
>>>>THANKS!!!
>>>>Haima Rowena J. Lucas
>>hrjlucas at ipc.hiroshima-u.ac.jp
Haima,
I routinely use mung beans in my Plants and Human Affairs
course for the auxin-induced adventitious rooting project.
It isn't original by any means. Basically I have students
plant mungs in vermiculite (planted deeply for a nice long
hypocotyl). Two weeks later (in the greenhouse) we harvest
shoots, trim the hypocotyls to 2 cm, remove cotyledons, and
stand them in 3 oz disposable plastic cups (sorry about the
English measures...they are bought in a grocery store here
in the US), in 20 mL of IBA dilutions. For non-majors I use
0 M (d H2O) as a control, 10-7 M IBA (too low to have any
significant effect vis a vis the control), 10-5 M IBA (has
a real nice stimulation), and 10-3 M IBA (herbicidal). The
students place 10 shoots in each cup for later counting and
statistical analysis. The cups of shoots are held under
fluorescent light fixtures (10 cm above the primary leaves).
I keep the solutions at about 2 cm deep by adding d H2O as
needed to correct for evaporation. This phase of incubation
is about two weeks, but can be as short as one week under
strong light, added minerals, and warm room temperature.
In my plant physiology course this year (for majors) not only
did we do a "tighter" and "longer" dose response, but we also
did other auxins. One group was really interested in mineral
nutrition, so they compared the IBA dose response with and
without added hydroponics minerals. Interestingly, the plants
with the added minerals responded much more quickly and much
more uniformly than plants in plain IBA dilutions.
The only downside I find to using the mung beans is that when
I add the distilled water, I have to be cautious about getting
drops of water on the leaves. Necrotic lesions do appear if you
leave water standing on the leaf for very much time.
I used to do this project in test tube racks (one shoot per tube,
ten tubes per concentration) but it was wasteful of glassware
(and/or cleaning if you still do that), and watering was a very
big CHORE! The clear plastic cups are cheap, disposable, and you
get the watering done VERY quickly. I use a wash bottle in topping
off the cups.
The exercise set up is in a "Future Preparations" document and the
Worksheet for the exercise is in a "Rooting" exercise in the
Plants and Human Affairs course area on my website. There is also
the briefest of writeups in my Plant Physiology course area...
I get THEM to do the thinking, preparing, and design of the
experiments in that course. I hate cookbook stuff for majors.
At first students don't like DIY, but later they LOVE it because
THEY get to ask and answer the questions.
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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