Re: Re: HYB: Freezing Iris Seeds
- Subject: Re: [iris-talk] Re: HYB: Freezing Iris Seeds
- From: j*@aol.com
- Date: Fri, 24 Aug 2001 13:09:23 EDT
In a message dated 8/24/01 9:35:13 AM Eastern Daylight Time, rives@home.com
writes:
<Paul has stated the difference between the freezing techniques
correctly. The human seed is frozen and stored in liquid nitrogen, the
iris seed is frozen much more slowly in the regular freezers.
Any moisture in either sample will form ice crystals that could disrupt
the germ plasma. The longer the sample takes to freeze, the larger the
crystal. The larger the crystal, the greater the damage. And the lower
the germination percentage.
Liquid nitrogen is very cheap (relatively speaking) and ice crystals do
not get a chance to form, the freezing is that fast. The seed/egg/embryo
are stored in liquid nitrogen. Hence the high recovery rate.
Cryogenic freezing would work in both circumstances of course. I
suspect that anyone who wishes to propagate (irises) via tissue culture
would have access to liquid nitrogen. Alternatively, if you just want
to ensure a very high germination rate from previously frozen material,
use liquid nitrogen to freeze the seeds initially, then move the seeds
to your regular freezer immediately. Do not allow to thaw.>
Paul, Sandra, Walter and others, thanks for an interesting discussion. I
have learned a great deal about the effects of freezing/thawing on cellular
structure and the process used when freezing human embryos...fascinating.
It's amazing what one can learn on iris-talk! I guess seeds from tropical
plants could be frozen and remain viable using liquid nitrogen (not that I
intend to try it, just curious).
Judy Hunt in Louisville, KY, Zone 6
------------------------ Yahoo! Groups Sponsor ---------------------~-->
FREE COLLEGE MONEY
CLICK HERE to search
600,000 scholarships!
http://us.click.yahoo.com/zoU8wD/4m7CAA/ySSFAA/2gGylB/TM
---------------------------------------------------------------------~->
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
