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Re: Hybrids (was E. cordifolius)



Sorry, for the long post since I am replying to James, Dwight and Roger in
the same mail.

I only know of one way to hybridize two species, and that is the
fertilization of gametes, resulting in viable seeds, which grows into a
plant with characteristics of both parents.
Dwight, I am sure you know very well that growing two different plants
beside each other doesn't result in hybrids if there is no fertilization,
right? Neither will they impart characteristics to each other. 

You don't need a botanist to tell you that you only get hybrids from seeds.
It is common sense.

I really doubt that the "bizzaro" marble queen Dwight mentioned in his post
are hybrids. I seems to me that these are different from the ones that we
know because their cultural conditions are different. E.g. Leaves that are
grown submersed or under low light tend to have less white mottled
patterns. I just want to clarify this before we have every hobbyist starts
calling their sword plant "hybrids" because they looked different from the
picture in their favorite plant book. Then, we will have even more confusion.

Roger wrote:
>Isn't a hybrid between two species *supposed* to be sterile?  

I wrote:
It all depends on the genetic material that you start with in the first
place. For example, all domestic dogs belong to the same species. No matter
how different they look, they still possess a certain degree of homology
and can still breed with each other. The resulting off-springs can also do
the same. Same with Humans. All of us are considered Homo sapiens, no
matter what race we are. When you have hybridization of two species, there
are a few possibilities;

1) You will not get any viable off-springs because the genetic material
from both parents is too diverse and normal cell activity cannot function
properly. In this case, it dies before you see it. (e.g. You will NOT get a
catfish from a cat and goldfish cross.)

2) The cells can function normally and results in off-springs. However,
meiosis/fertilization cannot take place properly, therefore is sterile.
E.g. E. osiris is a triploid (according to Tropica) (meaning it has 3 set
of chromosome), therefore is sterile.

3) the cells can function normally and the resulting off-spring can reproduce.

So it boils down to how close or genetically similar your candidates are.
You will probably never get anything from a Echinodorus and Barclaya cross,
or, a Guppy and Discus cross. In the case of swordtails and platies cross,
they are under that same family, so no big surprise there.

Tropica plants are produced through tissue culture. And there will be SOME
variations once in a while (called somal clonal variations). I believe that
E. ozelot "red flame" is obtained this way, through cultures of E. ozelot
"red". So all they really have to do is to wait for that rare mutant to
appear in culture.

Alternatively, we can subject the plant tissues in tissue-culture to
mutagens and hope that we get some appealing mutations. Or, if you don't
mind the workload, genetically engineer the plant look exactly how you
want. Currently, it seems that the trend is to infect plants with a virus
to get the variegate variety.

and James wrote:
>> 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.

I wrote:
Yes, but so is everything else. This issue is not limited to plants alone
(as others have pointed out). 

James, I am sure you won't support this by keeping any of the commercially
available hybrids, just in case they (a stray pollen) run amok into the
wild, right? ;)

Roger, care to share with us how you got your E. cordifolius seeds?

ck (who apprently is the only weirdo on APD who wants to hybridize aquatic
plants. :)
Singapore