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Kvilledude
My Weather
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| | Posted on Tuesday, December 07, 2004 - 07:41 pm EST : |   
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What does it mean exactly when one says that species clematis come true from their seed? Specifically, does this mean that the plant morphology, flower color, and fragrance (if applicable) all should be identical assuming no cross-pollination with another clematis? Is it just that the overall plant morphology and flower colors are the same but the fragrance may or may not come true? I guess I am wondering if there is a universally set definition that specifies what qualities of a clematis come true from seed for the species clematis. Thanks for any and all help.
Kvilledude
- North Carolina,
Zone "7A"
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Suzymac
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| | Posted on Tuesday, December 07, 2004 - 07:58 pm EST : |
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Miguel, even in species you can have very slight variation on occasion.....such as depth of color, intensity of scent, etc., but they usually come pretty true to their parent.
Of course, if the flowers were cross-pollinated with any other clematis you will get a hybrid which may be completely different, which you probably already know.
Suzy
Suzymac Massachusetts zone 6-A |
Kvilledude
My Weather
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| | Posted on Tuesday, December 07, 2004 - 10:02 pm EST : |
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Yeah, Suzy remember we had this discussion last winter I believe when I asked what the species clematis were exactly but I guess what I am asking now goes further. Can plants grown from species clematis seed actually show any variation and if so how much variation and variation in what parameters and still be considered species clematis? If the saying that species clematis come true from seed, what does that mean exactly as far as plant characteristics? If some variation is permissible, then how does that distinguish them from the nonspecies clematis which may look very much like their parent plants or may look very different? What is it genetically that makes the species clematis less susceptible to variation in from plants that arise from their seed (assuming no cross pollination of course) as compared to the other clematis?
Deep thoughts huh? LOL
Kvilledude
- North Carolina,
Zone "7A"
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Suzymac
My Favorite Photo
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| | Posted on Wednesday, December 08, 2004 - 01:08 am EST : |
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Miguel, I have a good example for you: Brian's Texensis seedlings, for example. Depending on the source for his seed, some were a very deep vibrant red, while other seed source plants are a more pinkish red. I have planted various seed sources to actually see the differences for myself. (Today, I had my first Texensis germination :>)!) The variation is slight, but noticeable to some.
When planting Viticella species seed, the color of purple can vary from a light purple to a slightly darker color of purple and some even have a bit of a lighter bar in the tepals. I saw this in Bill Bird's test garden where he had planted about 15 Viticella species seedlings and some were lighter purple and had a distinct lighter bar. I have read that some variation is to be expected in the wild, and all this without any cross pollination ! They were all UNMISTAKABLY Viticella species, yet there were some slight variations when you saw them next to one another. The flowers were all the same shape and size as their species. As I understand it, the variations in species are usually subtle if any. Just my observations. I know you want a more scientific answer, lol. I'll get out my 'The Genus Clematis' book by Magnus Johnson and see what I can find. It's a great book, by the way. I use it often. You might want to invest in one. It covers EVERYTHING you ever wanted to know about clematis, having about 800-900
pages of clematis information! I find it to be a complete 'clematis encyclopedia' ! You would love it, but it's a big investment, at about $100.00. However, I think it's worth that and more. Christmas is coming, you have an excuse now!
Suzy
Suzymac Massachusetts zone 6-A |
Addict
| | Posted on Wednesday, December 08, 2004 - 08:32 am EST : |
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Whilst not being a clematis expert I can offer comment on the genetics based on general Biological principles.
Species plants have a smaller gene pool and fewer alleles for each characteristic. So the amount of variation will be limited but not zero as there are different alleles (forms of genes to the laymman- not quite true but near enough for this). So any species plants that reproduce will show limited variation. There will be variation between different populations of the same species from different geographical locations.
There will also be variation due to spontaneous mutation in alleles. The copying process isn't always exact when DNA is replicated.
Indeed it is this natural variation, mutation and geographical isolation that gives rise to new (but closely related) species according to Darwinian theory.
as to whether plants are considered to be the same species or different - as classification is a man-made convention not a natural one then we can chose what is and isn't considered to be a different species. There are rules but like all rules there are exceptions!! Hence the reclassification and re-naming of species and the wonderful intense arguments in the world of Taxonomy.
Hybrids arise from natural or artificial crossing of different species. Thus any hybrid will have a much wider gene pool with many more alleles for each gene because they have the alleles from both parents. Many hybrids are crosses of more than two species so again the number of alleles will increase proportionally.
So in a species there may only be one or two alleles for a gene controlling flower colour and one or two that control position of colour producing cells in the flower. Therefore there may only be one colour form (say red) to the naked eye but over many plants this will give rise to deeper and less intense reds.
if you cross this with a species having only one colour form say blue depending upon how the alleles interact you may get red, blue or possibly purple flowers. Combine this with variation in the positional alleles for the colour you start to get picotee, stripes, spotted, blotched forms.
So now you can see it is virtually impossible for a hybrid to "come true" as it has many alleles which may not be shown in the parent but are shown in the offspring even if they arise from a self cross. This relates to Mendelian type theories of dominance, co dominance and recessive alleles. It's actually more complex than this!.
So now you can see why some of us (even scientists) like to forget the theory and just let nature do its job possibly aided by a judicious amount of hand pollination and selection.
I hope this helps answer your question to some extent Miguel and not confuse.
addict Staffordshire zone 8(just) UK |
Bengts
| | Posted on Wednesday, December 08, 2004 - 09:19 am EST : |
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Dear Miguel
I agree with most of what is said above and want to make a small addition. What happens in nature is up to the plants themselves and possibly insects. How to classify and name the result is up to us. This means that some botanists like to divide the same plants in several species and others to classify the same plants as belonging to the same species and possibly subspecies, varieties and forms. Examples are for instance C. alpina and C. sibirica which by some are classified as C. alpina subspecies alpina and C. alpina subspecies sibirica respectively. Both belong to C. alpina then! In this case the former is very separated from the latter, The Alps and Siberia (also in Finland and Norway). Dr Johnson found this classification unpractical but according to the Code both may be considered correct. Which one is chosen depends on the view taken by the scientist and also what is practical. I myself find it reasonable to use more division as C. sibirica is white and C. alpina blue and they are very separated in nature. To name all Atragenes as subspecies and varieties to C. alpina as some do gives very unpractical lengthy names.
Best BengtS
Bengts |
Kvilledude
My Weather
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| | Posted on Wednesday, December 08, 2004 - 09:54 am EST : |
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Thanks all for answering my question. I am beginning to have things gel in my mind as to how the distinctions are made.
Suzy, I remember in one of the recent articles by Brian that he said something about how when choosing which clematis to use in breeding purposes or which flowering clematis to keep out of the many ones that might be raised from seed that the salient point was to use or keep the ones which had the form most representative of the clematis in question. You are also right that I might soon have to invest in a copy of 'The Genus Clematis' book by Magnus Johnson.
Mike, I especially liked your biological approach to describing why the species have less variability possibilities than do the nonspecies. That was exactly what I was wanting to know about the potential for variability. I also hope you don't mind my using your explanation to clarify the minds of other people.
Bengts, I also thank you for your description of classification and naming and the resident problems therewithin. In the end it usually does come down to practicality in many matters in taxonomy.
Thanks everyone!!
Kvilledude
- North Carolina,
Zone "7A"
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Bcollingwood
My Garden
| | Posted on Wednesday, December 08, 2004 - 11:53 am EST : |
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Sorry Miguel, (("something about how when choosing which clematis to use in breeding purposes or which flowering clematis to keep out of the many ones that might be raised from seed that the salient point was to use or keep the ones which had the form most representative of the clematis in question"))
I don't actually recall quite saying that, or meaning that quite, which actual bit are you referring to, GH?
Brian Collingwood, Manchester UK |
Kvilledude
My Weather
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| | Posted on Wednesday, December 08, 2004 - 01:38 pm EST : |
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Brian, I think it was something that I remembered out of one of your two most recent articles but I am sure I mangled something in my translation of your text. LOL I will have to go back through those last two articles you wrote and see if I can pull out the information that I was meaning and when I do I will post it. Most humble apologies from someone who posted without enough caffeine in my system to actually go out and find the reference I was attempting to paraphrase! LOL
GH
Kvilledude
- North Carolina,
Zone "7A"
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Kvilledude
My Weather
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| | Posted on Wednesday, December 08, 2004 - 01:50 pm EST : |
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Here's the passage that I was thinking about Brian, but I see that it wasn't you who said it but you said that it is often referenced in books to...
One is often advised in books to ‘select the most floriferous form’, as, occasionally, though rarely in my own experience, plants do arise which are inherently not prolific flowerers.
Like I said, I was certain I didn't do justice to your actual text in my translation or maybe I should say mistranslation!
GH
Kvilledude
- North Carolina,
Zone "7A"
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Suzymac
My Favorite Photo
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| | Posted on Wednesday, December 08, 2004 - 03:24 pm EST : |
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Addict and Bengts, very interesting and informative responses. I'm always amazed at the caliber of information we have in this forum ! Excellent, thank you !
Suzy
Suzymac Massachusetts zone 6-A |
Katie
| | Posted on Wednesday, December 08, 2004 - 04:03 pm EST : |
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I was here during the discussion last year on this subject and still didn't "get" it. Now I do. Mike, thank you very much for your explanation. It is now much clearer. And thank you Bengts for your sidenote.
Katie
Katie
- Northern California,
Zone "8"
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Bcollingwood
My Garden
| | Posted on Wednesday, December 08, 2004 - 04:10 pm EST : |
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Oh Yes - the No. 2 article is there too, "Plants in Houses" - it has some overlap with the first one, but it has a completely different focus, and is half as long again, it is about establishing a collection mainly from seed, with some notes at the end which display my lack of botanical knowledge.
I posted it on the seed starter forum but here it is anyway
http://www.richardsdad.btinternet.co.uk/updates.htm
if you want to read it on-line.
Kate KVB kindly helped on it by proofreading versions of it several times and translating some of my hackneyed northern into proper english phrases. It's just another amateur effort, not been published yet, except on my site.
Brian Collingwood, Manchester UK |
Jeanne
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| | Posted on Wednesday, December 08, 2004 - 07:45 pm EST : |
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Ok..I have enjoyed reading all of yalls info..so, is this where i admit i am lost and totally confused?..LOL
Jeanne Texas Zone 8B |
Johninoz
My Time
| | Posted on Wednesday, December 08, 2004 - 09:41 pm EST : |
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Thanks for the explanations. I understand the theory to a degree but couldn't explain it in words even to myself. Reading a clear discussion makes the whole thing make more sense. I really do admire people who can explain things clearly and concisely!
Johninoz Victoria, Australia Zone 4 |
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