Tomato pulp experiment

Last season I tried an bit of an experiment with OP 'Westerland' seeds using tomato pulp as a means of improving germination of rose seeds. Basically, what I did was place the tomato pulp into a container with 50 rose seeds and left 50 untreated. The tomato pulp was allowed to ferment for 2 weeks and the seeds were taken out and stratified, along with the control group, for 6 weeks. The seeds were sown and the results we that 22 of the tomato pulp treated seed germinated and only of the control group germinated. That's 44% compared to just 4%. That was pretty interesting, so I decided to try it again this season with a different variety to see if the results were repeatable.

33 open pollinated 'Maurice Utrillo' seeds were placed into fresh tomato pulp and allowed to ferment for 2 weeks. 33 of the same kind of seed were placed into fresh water as a control. 'Maurice Utrillo' seed was chosen as it has traditionally proven difficult to germinate for me. After two weeks of fermentation both batches of seed were palced into moist paper towel and stratified in the fridge (starting 9th of July). Today I checked them and was struck by the condition of the seed.


After 40 days of stratification the control group is much darker and developing moulds and the pulp group look to be in far better condition. I wonder if this is part of the reason why the tomato pulp seems to improve germination? It looks like it suppresses fungal infection. The plan is to sow these seeds after 8 weeks of stratification and then compare the germination rates.

That's really interesting.
I wonder if the cultivar of tomato, and stage of maturity affects results also?

It's possible the acids in the tomato restrict the fungal development?

How do those results compare to rose seeds that are left in a hip (to ferment etc)?

Too many questions...!

Hi Wendy (it is Wendy right???)...

Here's the background thinking behind the experiment:

* Anyone who loves tomatoes knows that to save tomato seeds they first need fermenting. You do this by placing the pulp + seed into water and leaving it for about 4-5 days. This is because that jelly-like substance around the seeds contains germination inhibitors that prevent the seed germinating until they have been leached away. In the garden/natural habitat this occurs in two ways. The first way is when uneaten fruit drops to the ground and begins to ferment of its own accord. The second way is if the fruit is eaten and the seed is chemically scarified by the digetsive acids. Only after fermenting the seed do you get excellent germination of tomato seed.

* Analysis of tomato seed pulp shows that it contains enzyems (called lipases, cellulases and pectinases) which catalyze the 'breakdown' of lipids, cellulose, and pectin.

* So.... me thinking fo roses seeds thought this... rose seeds contain germination inhibitors. Many of these occur on the inside of the seed around the embryo in a thin layer of brown tissue called the testa. As the outer coating of the seed breaks down moisture can enter the seed and these germination inhibitors are removed and germination can begin. This just happens to last about the length of a winter season so the seed germinates at the beginning of spring.The outer woody part of the rose seed is in two parts joined together by a matrix. These two woody halves are said to be composed of cellulose and pectins and the matrix was said to be composed of something like pectin as well. My logic was that if the tomato pulp contained pectinase and cellulase then not only would they break down the tomato pulp but they might also breakdown the woody seed covers and maybe the suture between the two halves. In doing so it may also help to remove the germination inhibitors so the seed can germinate before fungus becomes an issue. A friend of mine has suggested to me that many rose seeds that don't germinate fail to do so because of fungus issues so in the race against the fungus, if the embryo can germinate more quickly then maybe it would improve the germination rate. Initial results seem to support this hypothesis, however, larger numbers are needed and repeat samples taken to generate any statistically significant data.

So... this is the basis of the experiment... The tomato certainly doesn't inhibit the growth of some fungus because at the end of two weeks in the pulp there is a nice healthy 'crop' of grey/white fungus growing on the surface of the pulp but maybe it does impart some kind of therapeutic effect to help give its own seedlings the best possible start... so I don't know how to account for the different conditions of the two batches of seed. They were treated in exactly the same way so the difference must be due to the pulp somehow. One theory that is bumping around in my head is that when you remove the seed from the pulp, the dark outer coat of the seed is almost completely eaten away. The difference is really quite amazing (see here: [You must be registered and logged in to see this link.] ). Maybe the fungal spores are in this layer and when it's eaten away the fungus is removed too.. or maybe the outer layer contains substances that are more suitable 'food' for fungi so when it's gone the fungi find it a less suitable place to colonise???? As you say... so many questions.

I knew it was about time to dust off the Biology Brain Cells. (And maybe a few Uni text books too. )
I presume the processes involved with a fermenting rosehip aren't as reliable as the tomato? Do they use the same enzymes? (I'm thinking about a few most-likely-over-ripe hips still on some of my bushes too.)
Certainly a lot to think about and digest.

(And yes, it's Wendy. In soggy NE Victoria.)

Is it possible other 'fruits/veg, could also used as a trial/experiment with the fermenting thought in mind. One comes to mind the, fermenting of say barley.

Might be worthwhile trialing some of the citrus fruits, pick the most sour tasting ones to start. Any with a low PH (Acid).

Pineapple has enzymes that assist in digestion... (protein.. but, still..!)

PIneapple and Paw Paw have been trialled before but I cannot remember the result of this. The reason why I thought of tomato is because the composition directly mentioned cellulases and pectinases... the two things others have discussed as being found in rose seed 'shells'.

As to all the other questions... at thispoint I do not know the answer to them... regarding the enzymes present in hips and fermenting hips... I don't know the answer. Some with a bit of time and some chooks cold test something else too Feed the hips to the chook and collect the seeds as they have passed through the system to see if this improves the germination rate (or you could eat them yourself if you are game ).

If a chook did this for me, how long would it take to pass the seeds, does one think.

Um... not sure to be honest... at least a couple of hours... would have to Google that one.

I remember the local gardeners getting there tomato plants from the local sewerage treatment plant. Some seeds are very durable.

What an interesting topic! I wonder if using oil of cloves when you stratify your seeds would help prevent or remove early fungul spores. Since the floods in Qld people have been buying and using so much oil of cloves that the shops have been having trouble keeping up with the demand.
Perhaps you would need to dilute it a great deal first.

I have a few thousand Multiflora seeds to treat with tomatoes so hoping for a good result.

I blame Simon for all this work opening hips, the seeds are so small. I am due to replace my Multiflora mother plants in a couple of years so hope the seed will be producing plenty of 6mm plus canes by then.

Multiflora will germinate like weeds without treatment, Bruce! You should try it with some Tea seeds to see if it improved the germination rate.

Got my first germination today from the control group (non-tomato-treated). This is the same result I got last time. The control group germinated first but more of the test group germinated. It certainly doesn't affect the rate of germination. Will be interesting to see if it affects the number of successful germinations though, like it did with the OP 'Westerland' seeds.