Re: frozen pollen viability, update

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Thanks Dennis for sharing your experiences and also you methods. Luckily I grabbed a large bagful of those canisters when I was still using film and use them for bleach/water treatment of the aril seeds before I plant them. Such a convenient size for all manner of uses.

Pat Toolan
PO Box 568,
Angaston
South Australia 5353
08 85 648 286

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From: i*@yahoogroups.com
To: i*@yahoogroups.com
Date: Fri, 13 Jun 2014 13:20:25 -0400
Subject: Re: [iris-species] frozen pollen viability, update

 

I try to harvest the anthers as soon as they mature.  (Bearded irises have a much longer window of opportunity to harvest them than beardless irises which often dehisce their pollen rather quickly.)  Depending on the species/cultivar this can be anywhere from 0 to 12 hours after the flower starts to open.  You'll know because the pollen will appear fluffy, or in some cases already starting to shed onto the falls.  I harvest them with tweezers & drop them into a 35mm film canister.  (Fujifilm has the best, opaque white canisters easy to write on with a Sharpie, and it wipes off easily to re-use another year.)  Use round-tip tweezers to avoid damaging the style arms.

I don't always remember to let the anthers dry out a little bit, but you should.  It doesn't have to be for long.  You just want to minimize the amount of moisture & humidity that gets captured in the 35mm canister.  It will condense during the freezing process and when you thaw it later the water droplets will destroy the pollen.  If you harvest pollen on a humid day, you want to let the canister dry out inside your air-conditioned home for a little while before you snap the lid on, for the same reasons.  You'll know thawed, wet pollen when you smell it.  It's musty & sour.  Fresh or dry pollen has a barely detectable pleasant odor.  (I suppose that varies by species/cultivar.)

Label the cannister with the name of the iris and the date (or year) you harvested it.  Don't label the lid!  Lids can get accidentally swapped.  :-)  Here's a pic http://signa.org/PC300001-pollen.jpg

Dennis in Cincinnati

On Fri, Jun 13, 2014 at 12:23 PM, Kathleen Sayce k*@willapabay.org [iris-species] <i*@yahoogroups.com> wrote:

Dennis

Thanks for mentioning this. Tossing the freezer yesterday I found 2 vials of pollen, an early flowering PCI and I unguicularis, from last year. My plan is to use them on early flowering PCIs next spring (as I had forgotten them this spring). Great reminder. 

Would you tell me more about how you stored your pollen?

Kathleen 

Pacific NW coast

On Jun 13, 2014, at 8:49 AM, Dennis Kramb d*@badbear.com [iris-species] <i*@yahoogroups.com> wrote:

6 to 8 weeks ago I asked around & around (on here, arilrobin, facebook, private emails, etc.) about the viability of very old pollen stored in the freezer.  Pretty much nobody answered.  Most respondents only keep it for 1 year.

I had about 18 anthers of Werckmeister's Clone #2 stored in my freezer.  They were from 2001.  They were still loaded with fluffy pollen.  As bloom season progressed I smeared that pollen on just about every cultivar that bloomed.  Pod after pod withered & died.  Except for those on Satan's Mistress.  I realize it's premature to jump to conclusions, but from appearances that 13 year-old pollen worked.

I had 3 anthers from Iris vinicolor from 2002.  I only applied it to 2 flowers:  one Iris fulva, and one Iris brevicaulis.  The fulva pod withered, but the brevicaulis pod is growing.  Again, I hate to be premature, but it's exciting to think that this 12 year-old pollen worked.

I have 6 anthers from Beuron (tet. pseudacorus) from 2002.  Encouraged by the other old pollen results, yesterday I started applying it to my tetra-versata flowers.  Fingers crossed!  Tetra-versata with tetra-pseudacorus could produce fertile offspring.  Fingers crossed!!!

Dennis in Cincinnati