Germinating super old seeds

[Adrian]

I use a cold frame coverd of one wintering veil fold in 3 and one wintering veil above the pots.
In the background i have put of clay balls.
The night the temperature is up 4°C > at out (minimum 2°C) and the humidity  is at 99%.
The day the temperature is up to 31°C above the pots and the minimal humidity is 30%.
I note that the humidity is more important than the temperature for the germination
It was a great sucess for the germination of my tetsukabuto seeds.Some seeds who look liked totaly flat are germinate.
But the more important before this stape is to put the seeds in water up to they sink or get fat.

[AndrewB]

I have nothing to contribute on the seed germination front. I just wanted to say way to go Joseph! And way to go for someone saving those seeds despite his early death!

Keep us up to date on the success of this!

[AndrewB]

Just learned that 4-5% alcohol soaking seeds can dramatically increase seed germination. Also 4-5% vinegar.

Similar to the 2-4% bleach.

There are a few scientific studies with graphs online from universities to back this up with data. Not sure if there is a synergistic effect of using them together, but would be curious to see a trial.

But alcohol and vinegar kind of make sense when you think about natural rotting fruits. I wonder how many inhibitors dissolve in alcohol easier that water. Some also speculate the alcohol vinegar may speed up germination and even help things like drought tolerance in corn.

https://www.csub.edu/~ddodenhoff/Bio100/literature/effectsofethanolonriceplants.pdf

https://emerginginvestigators.org/articles/presoaking-seeds-with-vinegar-improves-seed-development-and-drought-tolerance-in-maize-plants-ecc0efbf-524c-4a32-85c0-3d593827b8f9/pdf

http://www.ijsrp.org/research-paper-0315/ijsrp-p39122.pdf

I wonder if this would dramatically help hard to germinate seed such as rubus.

https://www.researchgate.net/profile/Abdul-Hameed-27/publication/287542665_Ethanol_priming_An_effective_approach_to_enhance_germination_and_seedling_development_by_improving_antioxidant_system_in_tomato_seeds/links/57016d5408aea6b7746a7cf7/Ethanol-priming-An-effective-approach-to-enhance-germination-and-seedling-development-by-improving-antioxidant-system-in-tomato-seeds.pdf

[Jeremy Weiss]

I might try this this year with my crowberry seeds (which I understand are also super hard to germinate).

[AndrewB]

Does anyone have robust protocols on how to germinate decades old pepper seeds to maximize success?

I have two packets of rare germplasm coming from ARS GRIN. I need to maximize success as I will only get one shot at this.

Last time I tried I had some seed get eaten by little worms in the peat mixture. Then I tried the baggie method and had one root but most seemed to die from too much water.

[Garrett Schantz]

https://tgrc-app.ucdavis.edu/seed_germ.aspx

I had to find this link, as I'm pretty sure some germination tricks shown here, also work with old seed.

And sure enough, they also mention old seed, briefly.



The main thing with old seed, isn't that it's no longer viable.

The cell walls, proteins and some other things are broken.

These protect the seed - AND seedlings from mold or other issues.

Plus, they provide the initial boost that gets them out of the soil and into a seedling.



Over time, those parts die off or break down.


So, it's not that they aren't viable usually.

It's mostly the case, that they dampen off or rot before they can germinate.


A lot of pepper species, take months to germinate.


GA3 may also help out.


Getting a plastic cover for seedlings, plus a tray. That helps keep up moisture.


Moisture levels for seeds - depends on the species.

Older seeds, must be sterilized and prepped to help them reduce any chances of rotting or having pre-germination issues.

Usually bacteria and things aren't issues to seeds. But, older seeds lose their coatings.

So the seeds should be sterile.


I don't know the measurements for bleach or other chemicals, for pepper seeds.

The amount and size, plus the species is a factor with that stuff.


There are some chemicals which may help restore or give proteins and things to seeds. I can't remember what they're called.

They're some form of coating.

There's also just standard, anti bacterial coatings.

I've heard of people trying out very thin layers of clay after doing sterilization and things.

But pepper seeds are very thin and small.

And old seeds have the issue of not being able to break through harder surfaces.


GA3 acid, is also pretty nice. It can also kill seeds if you overdo it.


I can try looking around for general guides.


It usually depends on exact species.

If you're germinating seeds on paper, you'd probably need to use something that won't have any paper residue sticking to it.

[Adrian]

Hi Andrew the little worm was probably the fly of the seedling.
I cover the potting soil of cellophane and i get a sucess at the majority.
Do you think that a porous material as cook clay (terracotta) for the pot can improve the breath of the root?

I know some people use sodium bicarbonate.

[Ocimum]

I have sucessfully used hydrogen peroxide to germinate bean seeds. I don't know if it would also work with peppers, and if yes, the ideal concentration.

[AndrewB]

I currently have at least one pepper seed germinating. These are from 1962. I assume kept in ideal conditions, but still. That is 61 years old!

I ended up using a modified protocol adapted from TGRC for the tomato seeds.

https://tgrc.ucdavis.edu/seedgermination

soak seeds in half-strength household bleach (final concentration ~2.7% sodium hypochlorite) for 30 mins.

 After bleaching, seeds should be rinsed for several minutes in running water, then sown directly, either on germination media (below) or in soil.

I ended up using a light hydroponics mix of seedling strength fertilizer to provide nutrients and micronutrients as well.

[Justin Jardinier]

Then I tried the baggie method and had one root but most seemed to die from too much water.

I've used the wet paper in a bag method quite a bit. I found sometimes it seemed important to make sure the paper isn't too wet - I'd squash excess water out. Also sometimes I got mould if left too long so I'd take the seeds out, rinse with H2O2 and put on new paper, sometimes even rinse new paper that way too.

Also with tomato seeds (various species) sometimes ones that didn't germinate, I then soaked in bleach, which worked really well. Some I also started with the bleach method. In both cases I used lower concentration and time than the TGRC protocol though. Like sometimes around 1:5 bleach:water ratio or even less, and usually for half an hour. Not sure if their method is better but this worked well so, seems ok to me.

With some wild pepper seeds I heard about if over a month no germination, try letting them dry a little then back to usual humidity. I did this by accident way before a month was up and some sprouted quickly after that. So, maybe protocols around that could be investigated, maybe for less critical seeds. Makes sense, maybe the natural soil would go through such cycles.

[Justin Jardinier]

Just learned that 4-5% alcohol soaking seeds can dramatically increase seed germination. Also 4-5% vinegar.

Interesting! Although... the paper you linked to 'Germination Response of Eggplant (Solanum melongena L.) Seeds to Different Vinegar Concentration as Seed
Priming Agents' indicates that even as much as 0.01% vinegar had a detrimental effect, but that 0.001% had a positive effect by the 7th day (though no different to the control by day 9).

Curiously they do mention someone else having positive, and another having negative, results at far higher concentrations:

The result of this study was in agreement with the experiment of
Borgen (2001) on vinegar in relation with concentrations' effect
and germination ability. Higher concentration have negative
effect on seed germination ability seems to be proportional to the
applied dose. In his study 0.5% of red and white wine vinegar
and 5% of white wine vinegar have simulative effect on
germination ability. In the experiments of Lövinson (1900) it
retarded the germination of peas.

Every concentration they tested above 0.001% was detrimental by day 7's results. Only 0.1% and 0.001% had more germination than the control by the 7th day (0.01% results seem anomalous in relation to 0.1%) but by day 9, all were worse than the control except 0.001% which was equal to it.

I also have doubts about this paper, when it says this:

On the 7th day the
treatment 6 (0.001%) showed higher number of seed germinated
compare other treatments but still comparable to control
treatment and treatment 4 (0.1%) while on 11th day, similar
pattern were observed in control, treatment 4 (0.1%), and
treatment 6 (0.001%). This greatly explains that the use of
vinegar as priming agent showed significant effect in
germinating seeds, particularly in increasing the number of
germination in early days such as on 7th day and 11th day.

Their words and their chart show 0.1 and 0.001 as being equal to the control on day 11, then based on that, they claim increased germination on day 11? Very strange.

Anyway the idea does seem interesting in terms of being able to use low amounts of vinegar to at least not be detrimental and maybe help against mould? I wonder maybe useful for slow germinating wild pepper seeds?

[AndrewB]

I had forgotten this thread was already started. Perhaps my newer thread can be merged here?

https://opensourceplantbreeding.org/forum/index.php/topic,867.0.html

I am sorry to hear about the lack of germination, Joseph.

I am happy to have at least one seed germinated of my 61 year old pepper seed from ARS GRIN. I still have 10 seeds left to experiment with or use the same protocol with. I'm thinking about soaking them for 10 min in the bleach solution and then putting 5 in the vinegar solution and 5 in the alcohol solution, but I'm not sure yet.

Justin, I notice they mentioned above that eggplant seeds did well with the vinegar solution, but peas did not. This is something I've been thinking about. Many tomato savers like to pre-ferment the seeds in the tomato juices, which are quite acidic. Basically, this is probably a naturally produced vinegar solution. In Peas, nothing akin to this occurs in nature to my knowledge, so those results do make sense to me. And vinegar comes after alcohol production, but I am not certain which treatment would be better than the other without rereading those papers I linked. In my mind the H+ ions of the acid could help break down dormancy barriers and stimulate germination, while alcohol could evaporate quickly and stimulate oxygen respiration?

and to reply to your comment in the other thread about soaking/drying cycles I think you are correct. At least for pepper seeds having not too much moisture and also having good drying out cycles is probably key to having any success. The question is how to germinate really old bean seeds that don't like to absorb water. Maybe the alcohol treatment would help?

[AndrewB]

Update on the 47-49 year old tomato seeds.

I tried a number of germination strategies with the seeds. Sterile conditions. Gradual rehydration. Tea from fresh seeds. M/S-Gamborg. Natural soil. Tried about 110 seeds total, with zero germination.

Today was tomato planting day. Therefore, I planted nearly all of the (700?) remaining seeds, under the same conditions as I've started tomatoes for years

Joseph, any update? Do you still have the trays where you planted these seeds? Perhaps don't give up on them yet. Maybe you can treat the soil with the alcohol concentration listed in the paper above / hydroponic fertilizer treatment (instead of water) and see if anything germinates after all this time?

[Joseph Lofthouse]

Nothing germinate from my super-old tomato seeds. I guess to be expected. They were stored in a warehouse that got super hot in the summers.

[Jeremy Weiss]

Nothing germinate from my super-old tomato seeds. I guess to be expected. They were stored in a warehouse that got super hot in the summers.

Yeah the do die after a while. I remember when I cleared out my "file cabinet" of tomato seeds I'd been accumulating since my college years (so up to 20+ years old). I tossed them ALL in a pot. exactly ONE came up, and I was shocked I got that one (more shocked that, given how even fresh tomato seed often performs poorly for me here, the resultant pant was actually quite productive).