6th grade Science Project on saving seeds

[spyfferoni]

My son has been thinking about doing a science project to see if there are good alternatives to fermentation. He thinks it is sooo nasty. I was wondering if using the oxiclean method and a rinse with a chlorine bleach solution would kill pathogens on the seed coats. He will mostly be testing germination of the different methods and weigh the pros and cons. It would be difficult for a 6th grader to determine if the pathogens remained or were destroyed, so his best bet will to find some sources of information on the subject. Can anyone point me in the right direction? The science fair isn't until the Spring, but he needs to do the seed saving techniques now while we have plenty of tomatoes. Then he can do the germination tests and document them in the Spring.

Thanks,
Tyffanie

Carolyn---if you see this would you be willing to answer some questions for him if he e-mails it to you? It would be neat for him to have access to someone who has published a book on heirloom tomatoes with tips on saving seeds. Thanks.

[Sun City Linda]

Tyffanie - That is such a cool project. Good luck to him! Wintersown has a method on their site which uses a chlorine type cleanser (Comet, etc) much faster and certainly smells much better. It appeals to me because I just do a tomato or two at a time. I guess I should sow a few seeds now and make sure I didnt nuke them. LOL Linda

[Worth1]

I think seed saving is dangerous and irresponsible. seeds should only be purchased through reputable companies such as Monsanto and the like.
These so called seed savers are the reason we have all of these terrible tomato pathogens running around.

This massage was brought to you by the Commercial Seed Producers of America. (CSPA) who have hacked into Worth's computer.

CSPA

[Boutique Tomatoes]

A bleach soak works for bacterial contaimination and TSP is normally suggested for viral contamination. I don't have anything specifc on tomatoes,.but I did have these two papers on treatment of pepper seeds bookmarked.

http://www.avrdc.org/LC/pepper/pepseed.pdf

http://www.avrdc.org/LC/pepper/PMMV.pdf

Google shows lots of hits for TSP treatment of tomato seeds. TSP can be purchased at any homebrew store, it's used for sterilizing your equipment and bottles.

* A large number of the USDA's collection of pepper varieties tested positive for pepper mild mottle virus, including the some of the ones I had requested for next years grow out. They sent along the info on the TSP treatment and I went and looked at some of the research, that's why I had it handy.

They do talk about reduced germination, but nobody gives specifics. I was actually thinking of sacrificing some of this years seeds for a germination test myself. I'd hate to treat the only 20 seeds I have of a variety and find out that only a couple germinate afterwards.

[cornbreadlouie]

Originally Posted by Worth1

I think seed saving is dangerous and irresponsible. seeds should only be purchased through reputable companies such as Monsanto and the like.
These so called seed savers are the reason we have all of these terrible tomato pathogens running around.

This massage was brought to you by the Commercial Seed Producers of America. (CSPA) who have hacked into Worth's computer.

CSPA

Careful, you may get a hot-winded, threatening email in the near future....

[carolyn137]

Tyfannie, of course I'd be glad to help your son any way I can, but I don't see that he can do what no one else has done and that's to determine the effectiveness of removing pathogens from the seed coat with oxidative methods.

We know much more about removal of pathogens from the seed coat through the work of Dr. Helene Dillard but this subject was brought up at another message site and there are some very good folks there and not ONE could find any data about the effectiveness of Comet, oxi clean methods in removing specific pathogens from the tomato seed coat. besides, specialmedia would be needed to do that and you wouldn't have access to that, I don't think.

Those oxidative methods have been discussed here at Tville quite a bit and if you do a search I'm sure you can find them. I think one place to check is the Settfest thread since i think that Feldon described it there.

TSP is known to remove TMV from the surface of seeds and while it's still used I don't know why b'c tobacco grown for the last 20 years has been TMV tolerant and the only place that it's known to be a problem is in large greenhouse operations where it's transmitted manually. And there was one small out break of TMV in CA a few years ago, insect transmitted.

Turkish tobacco is still suspect.

And almost all bacterial and viral pathogens tested to date have been found in the endosperm of the seed so no method that removes surface contaminants are helpful, What is helpful for them is hot water treatment and if you look in some catalogs you'll see that that treatment is offered for large scale farmers, but the major problem is that there can be significant loss of seed viability.

Tyfannie, I have only cat kids but I think I'd seriously consider letting a child work with chlorine and Comet and certainly not TSP since it's so caustic.

Fermentation is fine, but then what questions could be asked about that that haven't been already addressed.

If I sound like someone who has judged a lot of science fairs and asked the student what the parental input was I don't think you'd be surprised, you'd have that right. All it would take from me would be to ask the student a few questions to determine if the kids knew what they were doing and why and what the rationale was.

One issue could be his trying to ID the kinds of fungi and bacteria that comprise the mat that forms atop the gunk of different tomato varieties, b'c it is different just by looking at it but that's going to take special media and equipment for which there wouldn't be easy access, if any, sayeth the retired Microbiologist here.

[spyfferoni]

Carolyn,
I think the idea for the science fair is for the kids to have a problem, research, look for a solution, make a hypothesis, have some kind of experiment, and record the results. It doesn't have to be on something that is new, or groundbreaking. They seem to judge more the scientific process and work the student did. When my older son was in 6th grade, he made a cantenna and tested it/compared it to our wireless antenna, and no antenna to see which received an internet signal the best at different distances. He went to district and then region and won 3rd place in his category. Cantennas have been used for many years, but it was the process and documentation that helped him get so far.

As for working with chemicals, I would have him work outdoors and wear gloves and safety glasses. We would skip the TSP. I would be with him the whole time, and help him out when necessary.

I appreciate your willingness to help. My ultimate goal is for my son to utilize the scientific method and to learn and apply different methods of research. Sometimes it is hard to get my kids excited about anything related to school!

Thanks everyone!

[Sun City Linda]

Good one Worth. Really caught my attention until my eyes focused on "Monsanto" CSPA also a nice touch. LInda

[dice]

Cleaning seeds with tsp without fermenting them first may work,
but I find it to be an annoying way to get the gel off the seeds.
I bet your son would, too. (Too many repeats with more tsp before
they are clean enough to dry.)

With fermentation, the separation of seeds from gel happens while you
are off doing something else, which is way less tedious.

A reasonable project is just to try any different methods that
he can find documentation for and compare germination rates,
documenting his work.

[habitat_gardener]

You could let one batch of seeds dry on paper towels (no treatment), then do fermentations of varying durations: 3 days, 6 days, 12 days, 24 days. I think it'd be interesting to take photos of the fungal mat at different stages, maybe 1-day intervals, even if you can't ID the fungi and bacteria. If a hand lens or basic microscope is available, you could look for the little tails that indicate the seeds have started to sprout, then count the percentage and test the germination rates later.

Oh! and you could also try fermenting at different (above-freezing) temperatures, if you have a thermometer and have cooler/warmer areas that are ventilated enough.

I've seen some speculation that seeds fermented long enough to darken have lower viability. You could test that hypothesis.

You could do some samples with only tomato liquid, and add water to other samples. I've found that I need to add water to some of my fermentations because if I've saved seeds from only one tomato, all the liquid evaporates within a few days if I don't add some water. I try not to add more than 1:1, but you could test varying proportions of tomato:water. Or you could use other liquids -- for instance, would orange juice or lemonade work better than water? Or sugar water?

You could also do one batch where you determine "done" by noting the temperature and time, and another where you simply observe the fungal mat that's formed to determine that fermentation has done its job. Or look at individual tomato seeds/gel every 12 or 24 hours and describe what you see. (You can remove them with tweezers and place them on a piece of glass or clear plastic.)

And you could test drying methods: drying on coffee filter paper vs. less absorbent paper plates, in small flattish clumps vs. separating the seeds more, natural air drying vs. microwave or low oven, etc.

Anyway, I think there are a lot of variables that might be fun to play around with. If I were doing something like this, my hypothesis might be that this process has a lot of leeway, so I'd look for ways to test the boundaries of what you could do "wrong" and still end up with viable seed. I'd also look at Helene Dillard's research on fermenting seeds to remove pathogens to find out what's known and maybe to get some more ideas of what'd be worth testing and fun to do.