Scottish Rock Garden Club Forum

Specific Families and Genera => Hepatica => Topic started by: Duane McDowell on October 22, 2009, 05:11:51 PM

Title: Tetraploid Hepatica?
Post by: Duane McDowell on October 22, 2009, 05:11:51 PM
Is anyone aware of tetraploid or aneuploid Hepatica varieties?  I would be very interested in plants/seeds if they are available.
-Duane McDowell
University of MN
Minnesota, USA
Title: Re: Tetraploid Hepatica?
Post by: mark smyth on November 22, 2009, 12:45:08 PM
Duane I might be the only one but what does tetraploid and aneuploid mean and how do plants be that
Title: Re: Tetraploid Hepatica?
Post by: Rodger Whitlock on November 22, 2009, 05:32:41 PM
Duane I might be the only one but what does tetraploid and aneuploid mean and how do plants be that

The Boveri-Sutton chromosome theory (http://en.wikipedia.org/wiki/Boveri-Sutton_chromosome_theory) was one of the fundamental steps toward understanding how Mendelian inheritance worked (http://en.wikipedia.org/wiki/Mendelian). Contrary to Douglas Adam's statement in The Hitchhiker's Guide to the Galaxy and its sequels that 42 is the answer to everything, as far as biology is concerned, the answer is "two".

Mendel's classic experiments with inheritance in peas led to the idea that specific characters were determined by pairs of genes. The textbook example (one of the first thing taught in a course of genetics) is a simple recessive-dominant pair. In humans, a pair of this nature is blue vs. brown eyes, blue being recessive and brown dominant. Research in the century and a half since Mendel conducted his experiments has shown that the picture is generally more complex: few characters are dependent on a simple recessive-dominant pair of genes in such a clear cut way. Indeed, human eye colors aren't just blue and brown, but as an approximation, that's a reasonable place to start.

Thus, a single character is determined by a pair of alleles (http://en.wikipedia.org/wiki/Allele). The normal state of most organisms is that genes and the chromosomes which bear them occur in pairs.

Mother Nature loves complexity, and she loves misleading people, so non-two inheritance also occurs, but it is the exception. Humans normally have 23 pairs of chromosomes, or 46 chromosomes in total, but there are aberrant human genomes with more or fewer chromosomes.

The most common deviation is a doubling or even tripling of the entire chromosome complement to give, instead of the usual 2N count, 4N or 6N chromosomes. These are called "polyploids". A doubling to 4N is tetraploid, a tripling to 6N is hexaploid, and so on.

Aneuploidy (http://en.wikipedia.org/wiki/Aneuploidy) means that an organism only carries half the usual complement of chromosomes.

In humans, deviations from the usual 2N pattern (N=23) are usually fatal to the fetus, which spontaneously aborts, but some such variations may survive. Down syndrome (http://en.wikipedia.org/wiki/Down_syndrome) is a well known example. Individuals with idiosyncratic variations among the sex chromosomes leading to XXY, XYY, and such sex chromosome makeup are another category that is not always fatal in the womb.

I've written enough: go you to Wikipedia and learn more.
Title: Re: Tetraploid Hepatica?
Post by: David Nicholson on November 22, 2009, 07:20:26 PM
Rodger, that is fascinating, thanks very much for taking the time to post it. I must admit to having no scientific learning or experience and therefore much of what you wrote I failed to understand on first reading. I shall be back though and I shall follow all of the Links you have provided and I shall read the Wiki as well.
Title: Re: Tetraploid Hepatica?
Post by: partisangardener on December 17, 2009, 09:09:07 PM
I think the original Question meant. More vigorous plants(tetraploid). Or mutation shown at once (aneuploid). Which is very often the case with those plants.
So if anyone has such extremely healthy and sometimes stronger in all parts plants, I am intersted in seeds too, weather they are triploid or not. 8)
Sometimes they are only fertile with other tetras. Maybe they are selffertile??
I have never heard about such Heps though, but it is quite common in lilies and many human crop plants.
Title: Re: Tetraploid Hepatica?
Post by: Afloden on December 20, 2009, 04:59:48 AM
 As far as selected forms of typically diploid taxa (acutiloba, americana, asiatica, insularis, japonica, maxima, nobilis) - I know of none available. Of a check through my literature I have not seen any sampled randomly that proved to be tetraploid. You could always attempt to induce one through colchicine techniques. I am sure that a large sample of selected vigorous forms would turn up a tetraploid.

 The more lobed species (H. transsilvanica in Europe; H. henryi and H. yamatutai in China; H. nobilis var. pubescens in Japan) are all 2n = 4x = 28, tetraploids and are thought to have arrived at this state through auto- or allopolyploidy. That is why the H. intermedia (transilvanica X nobilis) are sterile.


 Aaron Floden
 Knoxville, TN

 

 
Title: Re: Tetraploid Hepatica?
Post by: partisangardener on December 20, 2009, 09:42:35 AM
Before You start to work with colchicine, keep in mind its a very strong poison and carcinogenic too. 8)
It was (is?) largely used in plantbreeding.
Title: Re: Tetraploid Hepatica?
Post by: zonneveld on March 15, 2010, 11:34:25 AM
It is along a time ago I wrote something to this forum Actually I lost contact completely. I will start again My article on all species and some hybrids of hepatica will appear soon In Plant Syst Evol. When it is out I can send you a pdf file to those interested.
The following hepaticas are tetraploid : H asiatica ssp pubescens, H yamatutai, H.henryi, H. transsilvanica and the hybrids transsilvanica x asiatica ssp pubescens.
Ben
Ben JM Zonneveld


(edited for typos)
Title: Re: Tetraploid Hepatica?
Post by: gote on April 09, 2010, 12:31:53 PM
It is along a time ago I wrote something to this forum Actually I lost contact completely. I will start again My article on all species and some hybrids of hepatica will appear soon In Plant Syst Evol. When it is out I can send you a pdf file to those interested.
The following hepaticas are tetraploid : H asiatica ssp pubescens, H yamatutai, H.henryi, H. transsilvanica and the hybrids transsilvanica x asiatica ssp pubescens.
Ben
Ben JM Zonneveld


(edited for typos)

Hi, I missed this thread. I would certainly be interested to readyour article.
gote@svanholm.se
Thanks in advance
Title: Re: Tetraploid Hepatica?
Post by: partisangardener on April 15, 2010, 01:23:57 PM
This one I saw a few days ago in a neglected spot due to destruction. I asked and got it. The flowers are 3,5 cm diameter very large leafs. Could be one.
They start light blue and bleach from outside inwards. Blue center stays.
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