Re: PC vs The Truth ?

["Karen Randall" <krandall@world.std.com>]

James wrote:

> I came across some information a few weeks ago on an Australian web site
> that dealt with how the seeds of some aquatics do have specific needs for
> them to be able to break dormancy - as I recall, they needed "smoke" (as
in
> from a fire) for them to germinate and there are companies which produce a
> "liquid smoke" which is supposed to do the same thing.

Remember, though, that seeds and tubers or bulbs are very different things.
Seeds are the product of reproduction, while tubers and bulbs are storage
organs.

>Maybe some
> Aponogetons come from similar environments (I don't know, that's only a
> supposition).

Aponogetons come from a variety of habitats, some of which dry out, others
of which don't.  There is so much variation from one species to another that
it's hard to make generalizations about them.

> I've been trying to grow a number of Australian aquatics from seeds over
the
> past few months. Some seeds sprouted almost immediately (well, within 36
> hours), others took a week, still others took several weeks, and one has
> still not germinated after several months, so there obviously is something
I
> don't know involved with certain conditions being required to break
dormancy
> in some species.

Do you still have seeds from the species that haven't sprouted that you
haven't exposed to water?  If so, you might try one of the following.  If
you have any information about the climate and conditions at the collecting
location, it might help you make an educated guess about what might work.

1. Some seeds actually need to be exposed to fairly intense heat, like a
forest fire.  This probably would be less likely for an aquatic plant, but
might, I suppose be a possibiliy for some marginal species.

2. Some seeds need a cold period followed by a warming up.  This might very
well be the case for some Australian plants.

3. Some species have seeds that are meant to be eaten by animals for
dispersal.  Some (a terrestrial example is morning glories) need to have
their outer coating nicked to be able to germinate.  Others have their
surfaces softened by passing through the digestive system of an animal.

4.  This last is a guess, but I would suspect that seeds produced by plants
that survive in areas of intermittent water supply would have a variable
rate of germination, just as killifish eggs will sometimes need more than
one submersion to hatch.  This strategy allows a species to survive a too
short wet season, by leaving some ungerminated seed (or unhatched eggs) for
the next rainy period.

Karen

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