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Growth inhibiting chemicals in Drosophyllum


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#1 This Island Earth

 
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Posted 29 January 2011 - 17:46 PM

1.) Does D.lusitanicum truly produce chemicals which inhibit the growth of other D.lusitanicum ?
2.) Does it affect the growth of other plants as well ?
3.) Does it affect the germination of seeds, how far apart should seeds be placed and, can you even germinate several in the same container if so ?
4.) How far apart should established plants be from each other ?

Sorry for all the questions, I'm trying this species for the first time and don't want to mess it up from step 1.
Thanks,
-Johnny

#2 Kamil

 
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Posted 29 January 2011 - 18:55 PM

That is very interesting point. It was published in some scientific article before. Personally I can´t belive in this.

I have sown many hundrests of seeds in past, mostly all was jammed on the soil surface on sown as a group of few to square trays. In my opinion no such effect on germination. Moreover no efect on later growing as you can keep a few plants in one pot for a many of the years.

That it is true, some batch of seeds may have lower germination rate. The pre-treatment is always necessary and well recommend. Also after germination about 30% seedlings may die quicky. But that is the other story.

I wish somebody will repeat this "sowing experiment" as it looks quite interestingly.

Edited by Kamil, 29 January 2011 - 19:01 PM.


#3 zeeland

 
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Posted 30 January 2011 - 13:40 PM

I have 20 seeds of them so i can try it.
will post the results later :yes:

#4 maxxima

 
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Posted 25 January 2012 - 21:08 PM

I can't say anything about established plants as this is my first attempt but so far I haven't witnessed any problems with seedlings germinating together. The biggest one here is the oldest one,

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#5 Dave Evans

 
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Posted 26 January 2012 - 22:26 PM

No, that story doesn't even make any sense. It poisons it own soil. Right :)

#6 amphirion

 
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Posted 28 January 2012 - 17:07 PM

No, that story doesn't even make any sense. It poisons it own soil. Right :)


actually, it's not too completely far-fetched. i believe pine trees use this sort of life strategy. Although they do not release any type of chemical from their roots, they are known for shedding their leaves, which leach tannins and secondary compounds into the ground. this causes the local surface to become relatively acidic and prevents most plant life from establishing themselves within the pine tree's domain.

that being said, although Drosophyllum has the moniker, dewy pine, i do not know of any allochemical warfare that Drosophyllum uses. and as shown, multiple Drosophyllum have been germinated in the same pot. i believe the line of thought was that when the first drosophyllum germinates, it releases a germination inhibitor hormone that prevents other seed from germinating---i dont believe that it kills younger seedlings...but that's how the theory goes. like i said, it already has been "disproven" with photographic evidence, although purposeful scientific experimentation would help validate things.

#7 BobZ

 
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Posted 29 January 2012 - 00:30 AM

Here are a few papers that might help this discussion.

http://www.sciencedi...304423809001745
http://www.mendeley....um-lusitanicum/
http://www.aloj.us.e.../pdf/Bego03.pdf

#8 Kamil

 
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Posted 30 January 2012 - 11:42 AM

What I don´t understant is the ecological sense of this behaviour against own individuals. I can understand this as some kind of protection againts competitive vegetation with difficulties, even the sympatric vegetation is not frequently so dense. Certainly thanks to occasional fire, which is the main factor of its limitation. There is also many other plants which contains phytotoxic components in their tissue, but small amout and quite selective.

Another reason is Drosophyllum always germinated in rainy season, and rain must wash away many of chemical compounds if there are any.

There is many of records from culture the close germination of Drosophyllum seeds is successful with no effect on germination rate. Also they can grow in closest contact. The future-death of seedling is mostly caused by unproper growing conditions by my opinion.

http://forum.masozra...&p=15510#p15510

Edited by Kamil, 30 January 2012 - 11:50 AM.


#9 maxxima

 
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Posted 30 January 2012 - 16:47 PM

Thank you very much for posting that link, Kamil!

I have 17 seedlings divided in 5 pots; I was really worried about them growing together. But after seeing Jan raised 9 of them in a pot, I am greatly relieved.

#10 Torsten

 
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Posted 30 January 2012 - 18:23 PM

What I don´t understant is the ecological sense of this behaviour against own individuals.


The ecological sense might be avoiding intraspecific competition. Two individuals from the same species have identical requirements, two indivivduals from different spieces normally don´t have identical requirements. Eleminating all other Drosophyllum-plants near by would ensure that the stronger plant doesn´t have to compete with an other Drosophyllum for nutrients, prey or water.
Perhaps there ist a coherence between the conditions the plants are living in (water or some nutrients) and the amount of phytotoxic components they set free. So it might be able to cultivate more than one plant in the same pot if the conditions are right. But this is just a gess.


PS: I have to excuse myself for my english, don´t know when I have written something in english last time.

Edited by Torsten, 30 January 2012 - 18:24 PM.


#11 Dave Evans

 
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Posted 01 February 2012 - 00:19 AM

Dear Torsten,

I do get what is being described. My issue with this theory is it isn't. It is a fantasy. First, Drosophyllum do grow together naturally in clumps. Second, they also grow by themselves naturally. So where would this idea of them killing off each other or somehow preventing growth in other individuals come from?

The first seed germinates and then inhibits other seeds from germinating? Whoa! This isn't even known to happen in any plants. (Wouldn't it be nice to discover a new signaling system in plants?) But it does sound rather similar to what happens when the first sperm gets into the egg...