Jamie; I agree with what you say but must take issue on one point.
"Cultivar" does have a precise defined meaning. The International Code for
Cultivated Plants (ICCP) gives a reasonbly precise definition with many
examples. Botanical terms as you know are defined by The International Code of
Botanical Nomenclature (ICBN), and you are correct when you say it (the
ICBN) does not have a precise definition of cultivar, since that is not a
botanical taxonomic term, but a horticultural term.
Clone is a scientific (specifically genetic) term. It is not defined
as a strictly taxonomic term and not defined by horticulturalists alone
either, but is essentially defined by all scientists and used throughout
botanical-taxonomic and horticultural literature.
Jamie; I know you are the authority on Daylilies and perhaps all registered
daylily cultivars are clones. But clone and cultivar are not synonymous
in other groups. Each cultivar may be a separate clone from the other
cultivars. But In other groups cultivars can be either clones or seed strains.
In Iris as I said most registered cultivar names designate a plant that is
propagated vegetatively (a clone).
Another way that clones are defined is products of asexual reproduction.
That is why they are genetically unique. Individual offspring of sexual
reproduction can be called a clone if they are subsequently repoduced
vegetatively (or tissue cultured) but until those idividuals are
reproduced asexually we would generally not use the word clone for a single
plant, but the set of plants thare are all genetic copies of each other.
Progeny of a sexual cross would have different genetic makeup and while each
individual could be called a clone upon asexually reproducing itself,
collectively the progeny of a sexual cross all have different
genetics.
I think we may have confusion with these terms becomes they are all used in
different contexts where sometimes they may appear to be synonymous but really
each has a special defined meaning.
Darlene I hope you are not totally confused. I live in NC also near Durham,
Where are you?
Am 12.12.2012 23:37, schrieb Darlene
Moore:
Jamie,
You mean there aren't any registered (registered with some governing
body) daylily that didn't come into being by sex! I thought one could
pollinate daylilies and then the plant grown from the seed would not be
considered a clone.
Darlene
Darlene,
although that was not the point I was
aiming for, as far as I know, there are no registered daylilies that were
asexually produced. If there were, they would be stabile mutations that
were then registered.
I think we need to step back a bit. The
concept of clone is much simpler than many of you are believing. A clone
is ANY unique genome. An example; we have just crossed two plants
belonging to different genetic make-up (two different clones) or not.
This doesn't matter. They produce seed. We raise this seed to new
plants. Each of these off-spring are clones. Genetically unique
units. Every seed will produce a unique clone. The only exception to
this is apomixis, which is found in certain plants, such as the genus Sorbus,
i.e., or parthenogenisis in the animal world. We may choose to name
some, as we have found them of quality, or we may decide to use them as
parents for another generation. This later group would typically be
refered to as Clone 1, Clone 6, Clone 12, etc. as a method of identifiing
them. All of these offspring are genetically unique. All are
individual clones.
As you see, it is a very simple definition.
The confusion has arisen due to the romance involved with the word.
Also, depending on your profession, the word may be used in a more specialised
manner, yet the definition is still the same. A unique
genetics.
Another item we are bantering about are the terms variety,
forma and cultivar. These have been recently sorted for
nomenclature. The word variety is now rarely used botanically, with
forma prefered. A forma is a described variation of an otherwise defined
unit. Thus, a taxon. A variety is anything, more or less, that can
be seperated from others. This has nothing more to do with taxon, clone,
etc. One can say the red varieties, the short varieties, the hardy
varieties. It is very general. This leads us to cultivar, which is
the contraction of cultivated variety. In other words, a variety that is
identified and further cultivated. It has no official meaning, although
it is amply used to speak/write of plant breeding/marketing, and so on.
It is not to be confused with a strain, which is a defined, non-clonal group
of organisms. It has variation, yet, enough qualities in common to be
placed under a strains definition/description. Snapdragons, petunias,
zinnias, etc are available as strains, as are many plants.
-- Jamie V.
_______________________
KÃln (Cologne)
Germany
Zone 8
