Date: Fri, 05 Sep 1997 00:50:33 -0400 From: Derek Glidden <dglidden@geocities.com> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg3385$foo@default> Subject: Hybrids and fertility
Jan wrote:
> This is *NOT TRUE* for all hybrids. In fact, within the limits of
> cps, only comparatively few cases of sterile hybrids in the genus
> _Drosera_ are known (cf. e.g. the masses of repeated crosses or
> hybrids involving no less than six different parent species in the
> genus _Nepenthes_).
Ok, well, my main focus on CP is Drosera, so this is probably where I've
drawn the wrong conclusions.
> Forget this wrong hypothesis ASAP! We are talking about *PLANTS*. The
> interspecific sterility hypothesis only applies to *ANIMALS* (and not
> even to all of them!), and perhaps a few other nasty creatures.
Ok, well, most, if not all, of my "genetics schooling" has been in high
school and college basic biology classes, where, naturally, they are
going to focus more on the "typical" genetic interbreeding
characteristics of animals.
I've also seen here and there references to numbers of chromosomes about
being able to create hybrids. Since I don't even VAGUELY understand
this reference ... ??? I'm guessing that species even within the same
genus differ widely on the number of chromosomes and only same-numbered
chromosome species can generate hybrids?
Most of my asking is because I'm starting to actually establish a number
of healthy species across several of the different types of CP (Drosera,
Nepenthes, Utrics mainly) and a few have started to flower, so I'm
wondering at what attempts at cross-pollination I should even try.
(Obviously I'm not going to try to cross my N.sanguinea with my
U.livida, even with the possibilities for generating a truly impressive
trapping mechanism... :) but I do have several within each genus that
may one day flower at the same time...)
Also, since some of my plants ARE hybrids, I'd like to understand the
difficulties or caveats of dealing with fertilization when/if they ever
flower. (And I know that at least a couple of my plants ARE sterile
hybrids.) For instance, I've heard/read at one place or another that
self-pollination of certain hybrids can result in seeds that will
germinate one or other of the parent plants? Is this even vaguely true?
> My tip: simply don't believe anything and only trust what you
> actually see. Very much is written and told, and only a part of it is
> true.
Or, perhaps the flip side of this point is that most of the talk I've
seen has focused on sterile hybrids, since fertile hybrids don't lend
themselves much to discussion about fertility.
> > And I suppose, along similar lines, since Nepenthes are male/female
> > differentiated, does it make any difference to your hybrid which sex
> > of which species you're crossing?
> There is definitely a difference at genetic level. Apart from
This is something I'd like to be able to learn more. Since I do have
several species of Nepenthes, and hopefully one day some might even
flower, since I know they're going to be sex-differentiated, I'd like to
find out what kinds of hassles or not I could look forward to if I tried
to cross-pollinate.
I suppose, considering the plants I'm mainly growing, I really should
just hunt down the Taylor and Danser books, and find out whatever the
equivalent is for Drosera...
> My modified general rule for hybrid fertility (and some other
> phenomena): General rules do generally not apply. ;-)
As is usually the case. :)
"Follow the usual procedures, except in cases where the usual procedures
do not apply."
-- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Derek Glidden http://www.illusionary.com Illusionary.com Home of the Pagan Resource Site Web development, database, graphics and general plumbing Linux, FreeBSD, Apache, MySQL, PostgreSQL, PHP (Say No to NT!)
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