Q: Inter-species crossing

Stephen M Jankalski CEREOID at prodigy.net
Thu Sep 2 16:03:27 EST 1999


Never said that. One was referred to the "rule book", the International
Code of Botanical Nomenclature. If you are disagreeing with anyone, it is
with that, not me. Those who agreed upon the rules out number and out rank
both you and me. It is also a much higher authority than your horticultural
references. I am just the messenger, I did not make the rules.

If you look in the International Code of Nomenclature for Cultivated Plants
(Cultivated Code), you will see under Article 2 that it says "The
International Code of Botanical Nomenclature (Botanical Code) governs the
use of botanical names in Latin form for both cultivated and wild plants,
except for graft chimeras." 

Different strains of a species can differ in traits that are genotypically
different, such as disease resistance, that do not appear outwardly
(phenotypically) different to the casual observer. Crosses between them
would still be considered to be hybrids and are.

I have noticed the attempt not to use the term "hybrid" in both codes and
in recent literature, probably for the reason you state. It has become an
imprecise and often misapplied term in common usage. The usage of the term
for animals has been different from the way it has been used for plants.
Lets not confuse zoology with botany and horticulture, they have their own
set of rules they follow.

Roger Van Loon <roger.vanloon at ping.be> wrote in article
<37CED36E.DD42A607 at ping.be>...
> Stephen M Jankalski wrote:
> 
> > Wasn't this already settled or did you just ignore the answer?
> Oh my - temper, temper. You probably mean: anything that you
> answer
> settles everything?
> > A hybrid is a hybrid regardless of the taxonomic ranking of the two
taxa
> > involved.
> At last, a definition for a hybrid (is it?)
> > Just look it up in the International Code of Botanical Nomenclature,
> > appendix I on the naming of hybrids.>
http://www.bgbm.fu-berlin.de/iapt/nomenclature/code/tokyo-e/Contents.htm
> Didn't you read my answer to that one - or did you just ignore
> the answer?
> 
> But Stephen, rest assured - I throw in the handkerchief. 
> 
> If you have read some of my postings, you will probably know that
> they were mostly based on the definitions in the many many books
> in my library, such as:
> - The RHS Dictionary of Gardening:
> ""Hybrid: a plant raised by crossing 2 species""
> - The Collingridge Encyclopedia of Gardening:
> ""Hybrid: ...For the purpose of botanical nomenclature, the term
> is
> confined to the progeny of crosses between distinct species or
> genera.""
> - Rhododendrons and Azaleas by Marvyn Kessell:
> ""A hybrid can be a cross between two species; two hybrids; a
> species and a hybrid; or, less commonly, two genera.""
> 
> But, apparently, the botanists have once again changed the rules.
> I have since learned that in the most recent edition of the RHS
> Dictionary the definition af a hybrid has changed to:
> ""Hybrid: the offspring of genetically dissimilar parents.""
> So who am I to disagree with such a definition which has clearly
> been brought up to date?
> Therefore, you're right. 
> Every existing plant is a hybrid - and every existing animal too,
> I suppose. My parents sure were genetically dissimilar (weren't
> yours?)
> So, speaking as one hybrid to another - thanks to the botanists
> for making the chaos more complete. I think the term "hybrid" has
> no meaning anymore.
> 
> Roger.
> 



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