red light sensitive lettuce germination experiments

[Helen J Michaels]

Hello all,

I've been running the classic germination experiments in my Botany class lab in which we expose lettuce seed to different light quality treatments (red vs blue vs green filters). In the past few years we have had really variable results in this experiment, but no problem with light vs dark comparisons. We've ordered special seed, exposed seed to far-red first, and tried elevating the temperature on a heat mat with no improvement. I am suspecting there is some change in the seed that breeders have generated. Anyone have any insights into how to get this to work? We usually check them after a week, but I am wondering if the response needs to be scored sooner and the "anomalous" results are due to the extended time frame. I've checked the archives and found a 1998 posting, but nothing more recent.
Thanks for any advice!

Helen Michaels

[Gross, Michael]

Hi,
I have had variable results too. I don't know of a good reason. I usually check germination after 48-72 hours.
Mike Gross


________________________________________
From: plant-ed...@oat.bio.indiana.edu [plant-ed...@oat.bio.indiana.edu] on behalf of Helen J Michaels [hmi...@bgsu.edu]
Sent: Tuesday, March 25, 2014 11:32 AM
To: plan...@net.bio.net
Subject: [Plant-education] red light sensitive lettuce germination experiments

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[Mark Spiro]

Helen et al.
We used to use the light-sensitive lettuce seeds from Wards for a number of
years with good results if you check them in the first 48 hours. Much later
than this time point there was essentially 100% germination in both the
dark and light treated seeds, which is not very helpful if your lab meets
once per week.

We have found two systems that work well over the course of one week.
Arabidopsis (Columbia ecotype) from Lehle seeds (arabidopsis.com) and
spores of C-fern (Ceratopteris richardii) from Carolina Biological Supply.

Both of these systems show typical red, far-red responses for germination
and are pretty easy to use. Of course they need to be examined under a
microscope to observe germination, which is a disadvantage compared to the
larger lettuce seeds.

On Tue, Mar 25, 2014 at 11:32 AM, Helen J Michaels <hmi...@bgsu.edu> wrote:

> Hello all,
>
> I've been running the classic germination experiments in my Botany class
> lab in which we expose lettuce seed to different light quality treatments
> (red vs blue vs green filters). In the past few years we have had really
> variable results in this experiment, but no problem with light vs dark
> comparisons. We've ordered special seed, exposed seed to far-red first, and
> tried elevating the temperature on a heat mat with no improvement. I am
> suspecting there is some change in the seed that breeders have generated.
> Anyone have any insights into how to get this to work? We usually check
> them after a week, but I am wondering if the response needs to be scored
> sooner and the "anomalous" results are due to the extended time frame. I've
> checked the archives and found a 1998 posting, but nothing more recent.
> Thanks for any advice!
>
> Helen Michaels
> _______________________________________________
> Plant-ed mailing list
> Plan...@net.bio.net
> http://www.bio.net/biomail/listinfo/plant-ed
>

--
Mark D. Spiro
Biology Department
Bucknell University
Lewisburg, PA 17837
Voice: 570-577-3486
FAX: 570-577-3537