Re: Tetraploids & Flow Cytometry
- To: hosta-open@mallorn.com
- Subject: Re: Tetraploids & Flow Cytometry
- From: h*@open.org
- Date: Sat, 10 Feb 2001 12:50:16 -0800 (PST)
Andrew:
>I have a reprint of the Flow Cytometry article and it is indeed
>worthy of a good long read, and I am a member of this robin.
I heard Ben make a lot of remarks on this robin about the significance
of his work and how we should all adore him for his effort, but he
NEVER presents any of his data or results on this robin.
Unfortunately, I don't have a copy of Ben's Flow Cytometry article -
I'm not an AHS member and I don't have any great desire to be an AHS
member. I would have a lot more respect for Ben if he would be
willing to present the results of his research.
>There are some differences between American methods and those of the
>Dutch, but I don't know whether these are significant.
I don't put a lot of faith in using flow cytometry to measure the
actual DNA concent of plants. It gets you close, but it's not the
absolute DNA content that we need to be concerned about. Flow
cytometry is quite good for seperating diploids from triploids from
tetraploids. You can scan a LOT of plants with less effort then to do
traditional chromosome counting. Lily hybridizers in Holland use flow
cytometry to find the triploid seedlings they like to use for
cutflower production. What I have a problem with is when Ben says
such a hosta has a DNA measurment of 30, another 34 and another 32 and
therefor the one with 32 is a hybrid between then other two, and makes
this conclusion solely on the DNA concentration.
If Ben and indirectly you want to promote tet hostas, then I wish Ben
would let us know just what hostas are tets so we can go and look at
them to see if we can actually see anything worth while about them.
>There are very good reasons that it is beneficial TO THE PLANT to
>have 120 chromosomes instead of 60, but I'll have to take some time
>to collect more references before I attempt to offer my more thorough
>response.
Now, Andrew, IF you are going to go head on head with me regards
tetraploid vs diploid genetics I suggest you first do a LOT of
preparation! Your statement that a plant is better off having 120
chromosomes then having 60 is nonsense that you can't support. Now,
please don't get me wrong, I don't have any bias against tet hostas,
and I do understand the value of increased gene and allelic
interactions in tets compared to diploids, but givendiversity that
already exists within hostas and their already large chromosme number
and likely amphidiploid nature, and the fact that we are dealing
mainly with the leaf as the main point of interest, I don't see that
converting hostas to the tet level (120 chromosomes) will have the
same impact as with other genera such as lilies or daylilies.
Now IF you still want to pursue breeding hostas at the tetraploid
level I suggest you forget about chemical conversion of diploids to
tets and instead look for hostas that produce unreduced gametes and
try that approach.
Joe Halinar
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