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Re: Hybrids (was E. cordifolius)

On Mon, 25 Sep 2000, ck wrote:

> I can't believe that not a single one in this list has attempted to
> hybridize an Echinodorus. Tell me this is not true. How about Aponogeton?

Me too.  What kind of gardeners are we, anyway?

Then James wrote:

> I can't speak for Dwight, but I have to agree with his (Dwight's) comments
> about amateur produced hybrids entering the marketplace through trades.
> Hobbyists (and frequently professional botanists) have a hard enough time
> identifying the particular species or variety a particular plant belongs to
> without the added confusion of random crosses to deal with.

This is true (at least for native fish) in some instances; some native
cutthroat trout are now absent or nearly absent, not because their
habitats are gone or because they are losing out to introduced species,
but because they're interbreeding with introduced rainbow trout and the
pure strains are disappearing.  I think this is also true of gambusia in

Isn't a hybrid between two species *supposed* to be sterile?  I believe
that is the classical definition of species, so the "loss" of a species
through cross-breeding has always meant to me that the taxonomists'
definition of the species was incorrect to start with.  I don't find a
large potential for error very surprising, because the taxonomists seem
pretty willing to change species and invent new ones to suit their needs.
Hence we have a gazillion different rift-lake "species" and more apistos
than you can shake a stick at [is that a common idiom?], despite the
appearance that their females are indistinguishable, even by the males.
There's certainly a lot of research money to be made from "finding" a new
species, then showing that the species is endangered.

> Large commercial
> outfits like Tropica DO experiement with hybridization, but they test all of
> their hybrids for suitability for aquarium growth before they release them
> onto the market, and I'm pretty sure that they destroy all those hybrids
> which fail to meet their criteria.

This is probably unnecessarily picky, but I think most of the hybrids and
sports sold by Tropica were actually developed elsewhere.  I don't have
much reason to believe there is any testing for suitability other than
just finding out whether the plant is robust enough to market.  I also
don't know that anyone has a program to destroy or prevent unmarketable

Also, I believe that CK was right about the popularity of hybrids.  I
think most of the large echinodorus now on the market are either hybrids
or sports, or sports off hybrids.  The small and medium-sized echinodorus
contain groups of plants that are so similar that you probably couldn't
tell whether they were hybrids or not.  Maybe they all are.

> I doubt many/any hobbyists doing kitchen
> table hybridization is likely to be as careful to ensure that only the very
> best results from any such crosses manage to infiltrate into wide
> circulation. The potential for damage (with plants) doesn't really affect
> the aquarium trade (if it doesn't grow well in an aquarium, people won't
> want to buy it...) but there does exist a potential problem for natural
> ecosystems should any of these hybrids make it into wild habitats where they
> could survive and possibly out-compete valid native species.

How much potential damage do you think there is from a weak hybrid?
Sterile hybrids don't breed and dead plants don't put out many seeds.

For what it's worth, when I asked the original question about growing E.
cordifolius from seed I had no interest in hybridizing anything.  Mostly I
would just like to say that I did it.  I'm quite surprised, as is CK, that
this group seems to have so little interest - or perhaps it's just little
experience - in that field.  There is a distinct advantage to rearing
plants from seeds.  Vegetatively produced plants are clones of the
original; there is no genetic diversity at all.  Plants grown from seed do
have more genetic diversity, and it's only through reproducing them be
seeds that we will ever see new strains developed.  That is true whether
those are hybrids, sports or selectively bred strains.

Roger Miller