Chironex

After reading some research about "thermodormancy" and seed germination inhibition, it is time to determine what effect, if any, the benefits of cytokinin treatment would have on banana/ensete seeds. Being largely recalcitrant, perhaps due to inhibition by abscisic acid (ABA) and thermodormancy, there appears to be a method of releasing these dormancies by stimulating ethylene production. These studies have shown positive results on breaking seed dormancy on clover, peanut and lettuce seeds.

As soon as I have secured the correct cytokinins, I plan to duplicate the experiment with banana seeds. It is hoped that these results may further improve banana seed germination responses.

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Scot

Bob

Thanks (I think) Scott I really didn't understand all you said though. I kind of got thermodormancy , but what about the ethylene thing? Should I put my unsprouted seeds in a brown bag with an apple?

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Chironex

Hmmm, why not? Try it and see what happens. Worst case scenario, they get mold on the outside of the seeds. I would suggest adding some powdered cinnamon to the bag. I would also try a paper bag and a plastic bag. Set it up by putting the seeds in a dampened (not soaked) coffee filter. Add some cinnamon powder, then fold it twice. Place this in a bag with your apple. See if they germinate quicker than a control group without the apple. Ideal temperature is around 25 C. Alternatively, you can fluctuate the temps from 17 - 25 C for 7-8 hours at the high end and 16-17 hrs at the low end.

It will be interesting to see what if anything happens. I will be using cytokinins to induce ethylene production. I may also use gibberelic acid to see if it makes any difference in germination in darkness.

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Scot

damaclese

Bob not to make fun of you but i was thinking the sam thing and it just made me laff LOL

Wouldn't it be a kick in the pants if after all the thousand of hr and millions of dollars people have spent in labs all over the world we find that just putting them with and apple in some brown paper bag did the trick i would just lafe my %#@^% off lol

O and my spellchecker said that thermodormancy is two words
thermo dormancy

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Bob

Thanks for putting this in simpler terms. The fluctuating temps did work with my Darjeeling Giant seeds. No effect with "reg" sikkimensis though as of yet. I'll try the cinnamin /apple recipe though on some Velutina seeds and see what happens. Anything with this combo can't be bad right?

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Chironex

Pauly,the spell checker is incorrect.Thermodormancy is correct. It is a combinative, single word.

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Scot

jmoore

I wasn't aware that apples produced ethylene (or ethene given its IUPAC name), at what point do they produce ethene? I always thought that bananas produce ethene when ripening, which stimulates the ripening of other bananas and indeed other fruit.

Wouldn't it be more logical to put a few banana seeds in a bag with a ripening banana?

As for sikkimensis, bloomin things, can't get them to germinate for love nor money. I'll try the ethene root, worth a go.

jmoore

Well I was wrong, apples do indeed produce ethene. I stand by my ripening banana idea, however.

damaclese

thanks for clearing that up i really need to go get a spell checker that has some sort of downloadabal area specific language data bases dose any one know of some good free-ware

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Chironex

I just wonder whether sufficient ethylene is produced to have an effect on breaking seed dormancy. But with an open mind, I move forward. I would like to ascertain whether anyone notices any difference in germination rates using this method. Note that ethylene alone will not be an end-all to breaking dormancy. There is a synergistic relationship in the presence of ethrel. This is where I will be focusing my experimentation.
Ethylene plays a hormonal-type role in directing growth, inhibiting growth, fruiting, blossoming, leaf dropping and other functions and is present in most plants. It is one of the most prevalent gases in nature. I see your logic about using a banana as an ethylene source, but I don't think it will make a difference what the source may be as ethylene is ethylene.
If you plan to try this, please set-up a companion test as a control group. Do everything the same, except do not add the apple, banana (or whatever ethylene source) to the control group.

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Scot

Chironex

OK, all of you chemists out there, I need your help, please. I want to end up with a dilution of 350 micro moles/liter of ethrel (Ethephon - 2-chlorethyl phosphonic acid) in final solution. I am starting with 1 pint containing .04 pounds per 473.16 ml, or (.33 pounds per gallon) from a 3.9% solution containing 96.1% inert ingredients. The molecular weight of this compound is 144.49401 g/mole. I need the final solution to contain .00035 moles of ethephon/liter.

How much would I need to dilute this to achieve the desired amount (350 micro moles) in my final solution?

By my calculations I would need to add 1.93757246 ml to 1 liter of water to achieve 350 micromoles dilution. Can someone please help me to verify this? (I would round it to 1.94 ml/L)


Thanks in advnce for your assistance!

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Scot

jmoore

OK here goes. The fact you have used two types of unit ie metric and imperial (US imperial at that) and sometimes together is confusing and you lose something in the conversion, so here is how I have interpreted it.

You start with 3.9% active ingredient, which is equal to 39 g / l (grams per litre) stock solution.

You need 350 micromoles in your final solution or 0.05 g / l ( based on the relative molecular mass you supplied of 144.something)

To reach that figure you divide your final mass of 0.05 grams ( as we are talking about 1 litre) by your starting concentration of 39 g / l which gives a figure of 1.28 ml / litre.

I'm sorry, but I don't understand pounds per US gallon and get especially confused when talking about pints. I think you can ignore the inert material as it's inert. On the bottle does it give a concentration as a percentage of active ingredient or a concentration in ounces per gallon?

Hope this helps.

Bob

jmoore, I get confused as well after a few pints!

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jmoore

I hear that, in fact going to have one right now. Cheers

buzzwinder

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Bill for my friend

Richard

Correct. You win this weeks proportionality quiz!

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griphuz

I'm still a little confused though about what breacks the dormancy, the cytokinnin or the ethylene?
So there are two possible experiment pathways, treatment with ethylene, and/or treatment with cytokinnin...
Regards,
Remko.

jmoore

That is the underlying issue with biology experiments, they have a lot of variables to control.

I'm sure, though that Scot will control those varibles and come out with a valid answer.

To answer your question, I suppose it could be one or the other or a mixture of the two, or something completely unrelated.

Michael_Andrew

I was kinda wondering what the effect if any there would be subjecting the seeds to the various enzymes, chemicals and the thermo dynamics of the digestive system. Anybody got a pet monkey?

Chironex

James, as you mentioned, it is the two in combination creating a synergy that trigger ethylene production and the inhibition of abscisic acid (ABA). Each of these plays a role in releasing dormancy.
Cytokinens and ethrel stimulate ethylene production in seeds. Further, the synergistic effects of ethrel and kinetin in stimulating polyribosome formation.
Significant variables are temperature, (at 35 C germination is completely inhibited) 25C is ideal; and Light (ethrel is promoted by kinetin in releasing seeds from photodormancy in light, or GA3 induced dark germination). Kinetin is capable of overcoming the inhibition of germination by high temperature, as is ethrel to a lesser extent, but the two combined have been shown to increase both the rate and percentage of germination.
Both kinetin and ethrel appear to be related to the expansion of cotyledons. They work together to assist in ATP synthesis during dormancy release in some seeds.
I should also include that these experiments were initially conducted on lettuce and Xanthium seeds. The trials I will be conducting may be the first efforts on Musa and Ensete seeds. Hopefully similar results will be realized.

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Scot