Saving Tomato Seeds Questions

[JamesL]

Originally Posted by ContainerTed

I've looked at this issue and have come to the following conclusion. I really don't have a need for this kind of "perfection". If I think the seeds I have are too infested with these internal seed pathogens, then I'll simply get some seed from a source that doesn't have the problem.

I can't afford and don't have the inclination to perform this kind of heat treatment with its precise temperature controls and all kind of other fusses. It isn't worth my time. Let the so-called professionals do this. I'll put my time to harvesting what mother nature allows me to have. I'll plant extras so that mother nature can have her share.

Fermentation should be adequate for all my needs. I also do a process where I use Comet or whatever other scouring powder I have at the moment to scrub away the gel sacs. I also do a Clorox rinse on seeds coming out of the fermentation process. But, I don't do any of these things all of the time.

It's nice to know this "heat" process in case we need to "save" a variety from extinction. But it is not for me for my everyday use. This is just my lazy "70 years young" opinion. But, I know and respect that you may choose a different view.

Agree with you completely Ted!

[greyghost]

I agree with you, too, Ted. I think the value of the discussion, especially
to new gardeners/seed savers, is that some pathogens could be passed on
with the seed. It pays to know what diseases your plants/fruits may have
and hopefully, not pass them on to others. I guess I feel lucky I've never
gotten bacterial speck or similar diseases through traded or purchased seed.

[JamesL]

Originally Posted by greyghost

James, Thanks for posting that link. I was surprised at the number of possible
seed borne diseases for tomatoes.

Agreed. It surprised me too the first time I read it.

[carolyn137]

Originally Posted by JamesL

Agreed. It surprised me too the first time I read it.

If you look closely at that list you'll see that some of the pathogens listed are said to be seedborne but are only found on the exterior of the seed, mainly the fungal ones, but bacterial, viral and viroid ones are on the interior only.

I think I referred to Dr. Helene Dillard above and what she showed was that fermentation was effective in removing almost all of the fungal ones from the seed exterior, and that infection is quantititative so that lessens the chances that actual infection will occur.

And as I also noted, studies such as hers have not been done with oxidative methods. Several folks have tried, and failed to find the efficacy of oxidative methods for tomatoes and Imention that b'c there is data for other kinds of seeds. But then Dr, Dillard had large grants, from either Heinz or Campbells. to fund her research.

Carolyn

[BlackBear]

Originally Posted by carolyn137

If you look closely at that list you'll see that some of the pathogens listed are said to be seedborne but are only found on the exterior of the seed, mainly the fungal ones, but bacterial, viral and viroid ones are on the interior only.

I think I referred to Dr. Helene Dillard above and what she showed was that fermentation was effective in removing almost all of the fungal ones from the seed exterior, and that infection is quantititative so that lessens the chances that actual infection will occur.

And as I also noted, studies such as hers have not been done with oxidative methods. Several folks have tried, and failed to find the efficacy of oxidative methods for tomatoes and Imention that b'c there is data for other kinds of seeds. But then Dr, Dillard had large grants, from either Heinz or Campbells. to fund her research.

Carolyn

ahhh yes ! light bulb going off !

It is the total inside and outside pathogens ...Plus other environmental grow conditions/stresses...... ( plus variety selected genetic disease resistance )

that will decide the chance of the disease to express itself in the cultivare.



Normally the fermentation or oxidation method for outside fungal treatment is enough

in normal healthy cultivation environment for plants to grow and reach maturity and produce fruit.

It is the tried and true standard way. the Gold Standard.


..I am just wondering if there is any justification in saying if you also had heat treated seeds that were devoid of the inside bacterial / viral pathogens as well.........(most of these pathogens which we would never be aware of ...and still have good production ! ) would one not increase the chances of a healthier plant and get a potentially a better production ???

I don't know if it is worth it for everybody ...but I think there are a lot of " Tomatovillians "

who would like to get all the best factors lined up to increase the outcome ...chances.

If a plant does not have to spend resources to fight/defend against disease with a disease response ( even invisible to the normal eye )...will it actually grow / produce better ?


oh geese I can't believe I said that ............

[ChrisK]

These links might be useful. I was just looking this topic up because I'm having an issue with a vascular wilt and wasn't sure if I should save seed from those plants.

Instructions for bleach or hot water:

vegetablemdonline.ppath.cornell.edu/NewsArticles/HotWaterSeedTreatment.html

ohioline.osu.edu/hyg-fact/3000/3085.html

www.highmowingseeds.com/SB-Seedborne-Disease-and-Its-Control.html

[BlackBear]

Originally Posted by JamesL

Hot water treatment is tricky. I would also not suggest it unless you have a PID controller and the ability to set up a proper hot water bath.
http://vegetablemdonline.ppath.corne...Treatment.html

That being said it is useful to have in your bag of tricks if you think a seed source is questionable.

The link is good ...and the awareness of seed bourne pathogen internal that heat treatment fixes is interesting ...........does anybody know of some dreaded pathogen that for some reason will not be fixed with the standard heat treatment of 50C/ 122F @25 minutes ???

[FLRedHeart]

Originally Posted by BlackBear

The link is good ...and the awareness of seed bourne pathogen internal that heat treatment fixes is interesting ...........does anybody know of some dreaded pathogen that for some reason will not be fixed with the standard heat treatment of 50C/ 122F @25 minutes ???

Interesting subject. A scientific answer would require a survey of the literature
to answer that question for each individual pathogen to characterize its
individual behavior and a variety of circumstances, for example a spore might
withstand a much greater temperature than the corresponding organism:

Most sources quote that heat treatment is especially useful for bacterial
diseases present in the seed endosperm. It is also used to control viral and
fungal disease, but typically in industry seeds are treated with fungicides and
other biocidal chemicals, even in addition to different heat treatments.

Since we are dealing with living organisms, I think looking for a yes/no answer
is an oversimplification. My impression is that heat treatment reduces all these
pathogens to minimal levels if it doesn't eliminate them, but there are no
guarantees in nature. Some pathogens are more stubborn than others, and
each seed presents a different microscopical situation. I would liken it to
chemotherapy in which you get a great success rate and appear cancer-free,
but somewhere, there could be lurking something that for some random
reason persisted. Life, (including viruses) is tenacious.*

Perhaps a virus could have a greater chance of persisting.

I heat treat all of my seeds by the standard 25 min @ 122 F, and have
never had a wholesale problem of seed mortality. It is true that older
seed seems to have lower germination rates after applying a heat treatment,
but to say anything more, a controlled experiment under the specific
conditions is the way to go. After all, it is older seed, and I don't know the
conditions it was stored under. If only 6/10 germinate instead of 9/10, how
would I know why since I don't run a replicated, controlled statistically
meaningful experiment comparing heat treated to non-heat treated of
uniformly produced and stored control seeds. The literature claims that seed
over 2 years old really can suffer greater mortality. I take the researchers'
word for it so far as sounding plausible. If someone stuck me in a bath of
122 F for 25 minutes, I'm pretty sure I wouldn't even live 5 minutes. But I
would be sure to binge on unsaturated fatty acids if I had advanced notice,
and do whatever I could to increase my odds of survival. Who knows, life
usually finds a way to surprise!

* "Life is tenacious." Apparently I'm getting old, since "tenacious" is not the
word I want here. There is a quote that is more of a one line zinger with a
synonym to tenacious that I was looking for, but my memory is on holiday :-(

[BlackBear]

so after heat treatment of 122f/50 C @25 minutes .........

one may possibly loose some seeds and possibly not all pathogens would be eradicated from inside the seed....but the resulting viable seeds from the process have a better start and chance in regards to disease ........as the fermentation and oxiclean methods would not remove the pathogens bourne inside the seed itself.

[FLRedHeart]

Originally Posted by BlackBear

so after heat treatment of 122f/50 C @25 minutes .........

one may possibly loose some seeds and possibly not all pathogens would be eradicated from inside the seed....but the resulting viable seeds from the process have a better start and chance in regards to disease ........as the fermentation and oxiclean methods would not remove the pathogens bourne inside the seed itself.

Yes, the temperature was probably determined by trial and error more than
anything else, just giving seeds thermal treatments to just before a serious
viability issue developed.

It may be overwhelmingly effective for most problems. But take for example,
Tomato Mosaic Virus. For that one the recommended treatment is for a longer
period of time @ 158 F under dry conditions. Different thermal situation.

Heat treatments done properly I've heard is not supposed to have a negative
effect on the growth of the plant. I'm sure there are studies on this, but I
never read any. In our situation, though, when we swap seeds or deal with
small outfits, frequently old seed shows up. I suspect there is a negative
effect on the eventual plant or yield, but again, these are impressions and
really would need to be proven by experiment. Plus as long as the variety
produces we then start over with our fresh home-grown seeds next time,
so I consider it the cost of getting a new free variety.

[Gerardo]

A run of the mill lab water bath can handle the 50 C in its sleep, alas, I think it's a bit silly to acquire one just for this purpose.

The pyrex + hot kettle appears straightforward and relatively easy to set up in any kitchen. Thanks for the link to the senior gardening hot water treatment.

[carolyn137]

Just some observations about this thread.

First, Black Bear, you are in BC, Canada, and your main problem there are the foliage diseases, just ask others from BC, and Tania, who is in BC as well, who has that superb data base website has the same foliage disease problems as well.

From the first post I did here I've continued to follow the thread and I am truly surprised that several of you are still suggesting hot water bath treatments, but not surprised with those who say to forget it, with which I agree.

It all depends on where you live and what the most prevalent tomato diseases are, and whether you are a hobby gardener or a commercial large scale gardener. Just look in any of the catalogs where for a single variety seed is offered with and without hot water treatment and for what price. Almost all commercial growers that I know will request the hot water treatment specifically for its ability, when done properly, to inactivate most of the bacterial pathogens in the endosperm of the seed,

And I say most, since new pathogens are being discovered all the time.

Those in the south and along the Gulf coast up into lower CA have other pathogens to think of and the several gemini viruses are a major problem.

https://www.google.com/?gws_rd=ssl#q...i+tomato+virus

The insect vectors for most of those are only found in the south, or were until recently.

Then there's new info on the Potato Spindle VIROID, not virus, which also can infect tomatoes, and here in the US.

https://www.google.com/?gws_rd=ssl#q...e+tuber+viroid

And now a link from the above Google Search

http://vegetablemdonline.ppath.corne...rus_Potato.htm

My professional life was one of teaching and doing research and I've had more than my share of trying to keep water bath temps where they should be and for how long they should be kept to accomplish the procedure under way. It is not easy and I didn't have any seeds to worry about in terms of losing viability and there's lots of info on the net as to the degree of loss of viability that can occur.

I think it's a complete waste of time for a hobby gardener to try to inactivate something in the endosperm of a tomato seed when not all possible pathogens have even been studied that might end up there as opposed to the known fungal pathogens on the seed surface which are well known and DATA is available to indicate the efficacy of fermentation in lowering that fungal burden but is NOT available for any of the oxidative or bleach methods.

Summary? I think the suggestion to use hot water tratment to inactivate what is not even known to reside in the endosperm except for those viruses already tested and studied, which is not all of them and VIROIDS can't be tested b'c they are not the same as viruses and have to show genetic recombination within the endosperm to form a viable particle, whereas viruses can replicate independently.....is not a good idea.

I could be stronger that that in what I say, but won't. You have to know WHAT it is you want to inactivate to start with and that simply is not known for especially those viruses and viroids that can only be studied in PLANT cell culture, which introduces yet another barrier to making progress in this area.

Carolyn, now asking Freda to take a look at her few tomato plants in containers in the back yard to see if any deer had breakfast there or with all the rain if they need a shot of fertilizer and if they need to be sprayed with a good antifungal b'c of all the rain,

[ChrisK]

Posted elsewhere is a simple method of using a thermos. You need an accurate thermometer too.

Get the water to the temp you want in the thermos and put the seeds in for the desired length of time. I can confirm that over the 25 min it will lose maybe 1 degree.

There are tons of papers that describe surface sterilization of tomato seeds with bleach.

Originally Posted by Gerardo

A run of the mill lab water bath can handle the 50 C in its sleep, alas, I think it's a bit silly to acquire one just for this purpose.

The pyrex + hot kettle appears straightforward and relatively easy to set up in any kitchen. Thanks for the link to the senior gardening hot water treatment.

[AlittleSalt]

Carolyn, you have really helped me to understand. Thank you.

I have a related - but totally separate question:

I got cherry tomato seeds from a swap that do not grow well. The germination rate is poor, the plants grow stunted. and produce only a few tomatoes at best. My question is, "If I were to save seeds from those few tomatoes, do those seeds have much of a chance to grow healthy productive plants when planted next growing season?"

The seeds are not rare or anything (Black Cherry) and I'm thinking that it would be better to toss the seeds I have and just buy some more. But, I am curious about the question above.

[carolyn137]

Originally Posted by AlittleSalt

Carolyn, you have really helped me to understand. Thank you.

I have a related - but totally separate question:

I got cherry tomato seeds from a swap that do not grow well. The germination rate is poor, the plants grow stunted. and produce only a few tomatoes at best. My question is, "If I were to save seeds from those few tomatoes, do those seeds have much of a chance to grow healthy productive plants when planted next growing season?"

The seeds are not rare or anything (Black Cherry) and I'm thinking that it would be better to toss the seeds I have and just buy some more. But, I am curious about the question above.

Robert, the major reason I have never participated in a swap and never will, is b'c you have no idea where those seeds came from, geographically re possible tomato diseases, nor who donated the seeds and how they might have processed them.

Only once had I set out several plants of the same variety, and I knew who produced them, but not how they processed them until it was too late, and I could see no evidence of any foliage diseases and they were so stunted I pulled all of them.

All to say I would definitely NOT save seeds from any fruits, rather, I would buy new seeds,

http://t.tatianastomatobase.com:88/w...b=General_Info

Why not buy them from Tomato Growers since it was Linda's late husband Vince who bred them, Tania says from a natural cross but Vince bred them, not from a natural cross.

When looking at seed availabiity Tania has not updated for 2015 but most of those places I'm sure still have them.

I talked to Linda about them and suggested what Vince might have used, but obviously she was not willing to speak to that. I was one of a few who bought seeds when they were first listed it and the germination was horrible. When I asked linda about it, she's been a long time friend and I've sent many seeds to her for trial, she said that that first batch of seeds had too many immature seeds in it and that's why the germination was so bad. They had not contracted out seed production for it, did it themselves and didn't have that much experience doing it.

However, saving seeds from fruits that did appear gave close to 100% germination when sowed, so indeed it was an immature seed situation at first.

So buy some new seeds and get rid of those stunted plants.

Carolyn