Re: ploidy of S # S (& Chimeras)
RE:>> I find that interesting that Hosta have polyploidic cytochimeras,
unexpected. Ben which plants did you find were polyploid chimeras?
RE:>>The article that Ben Zonneveld and Frank Van Iren had published
in Euphytica 111:105-110, 2000.
In Table 2. "DNA Content in ploidy chimeras of Hosta, measured with
Propidium Iodide", the authors list the following as being Ploidy Chimeras:
U. 'Middle Ridge' (Is that "U" for Undulata?)
Fortunei 'Patriot' 1
Fortunei 'Patriot' 2
plantaginea 'Heaven Scent'
One of the statements in the article is perplexing to me:
"Based on the low pollen stainability and seemingly aneuploid offspring,
'Sum and Substance' must be considered a triploid. However, the high DNA
content indicates that H. ventricosa is not one of the parents.
I have to admit that I need some help with the reasoning
here. H. ventricosa 'Aureomarginata' shows pg DNA per 2C nucleus
at 41.6 and it is concluded that this plant is a tetraploid. H. 'Sum
and Substance' shows pg DNA per 2C nucleus at 39.0, at the high end of
those listed as triploids. I'm not questioning the results, I'm just
trying to understand how one draws the conclusion that 'Sum and Substance'
could not have H. ventricosa as a parent from the data alone.
Maybe Ben, or someone else, can help me out with this.
There are a couple of places in the Euphytica article where further
translation into English may be warranted. This could be part of
the reason, Ben, that sometimes your articles aren't immediately published
in the AHS Journal--i.e. the editors are still trying to figure out what
you are saying. This could simply be due to translation questions,
perceived demand for articles of a rather scientific nature (lots of people
don't even enjoy knowing this much about a plant). I am not an editor
so I am uncertain why this could be occurring, but I for one have appreciated
articles of a more scientific nature, and this certainly includes the only
two that I am aware of to date.
This statement is a bit confusing so I could use some help with its
pg 108: "This suggests that the higher DNA content in some cultivars
was due to an increase with DNA of a similar AT (Adenine-Thymine) content
as found in the plants with the lower DNA content".
With this one I could use some help also:
pg 109 (toward bottom left). "The tetraploidy of the L3 is corroborated
by the roots in which only tetraploid (4C) and 8C cells are present".
--- I thought for a moment that the legend for the terms 2C and 4C would
be 2C=Diploid and 4C=Tetraploid. However, with the introduction of
the 8C acronym, now I am uncertain. (if the C=Chromosomes,
what does 8C equal?)
Paul wrote:>>If the generation of polyploids is "common" in tissue
explain why some plants come out of culture and do not grow well.
This I am curious about as well. Probably 150 of the 230+ new
varieties I added this year were TC plants. I found I had
more trouble establishing some of the mature crown plants than I did the
vast majority of any TC stock. H. longipes 'Aurea', H. 'Lady
in Waiting', H. fortunei 'Aoki', H. 'Blue Mammoth', and H. 'Aqua Velva',
to name a few, were tough to get going in their containers. I did
have a couple of TC plants that were harder to get going, too, but I attributed
this more to their plant lineage than having anything to do with them coming
from the TC means of propagation. Later, I made the same conclusion
about the above referenced mature crown plants.
For a while, I was looking at a tray of H. 'Big Daddy' (TC plants)
and saying, "What is wrong with you? Grow, grow!!!". They looked
anemic--no growth, the edges of the leaves were browning, and I thought
they were dying or had contracted some disease. Eventually, as I
was repotting and moving some of the blues into the ground for wintering
over, I discovered that for many of these, all of the growth activity had
been going on in the root systems--they were just going dormant early but
were busy putting on "adventitious divisions" (I'm still not certain that
I am using this terminology correctly. Anyone wanting to offer
concurrance to its proper use, or that my useage is abominable, have at
it. Are the divisions that emerge from the bottom of a stem
"adventitious roots" or adventitious divisions", or both?).
Paul--Could you elaborate on your statement about some TC plants not
growing well? I'm particularly interested in discovering whether
my conclusion, i.e. that good or poor adaptation to growing-on TC liners
in containers has more to do with the plants inherited genetics (species/parentage),
than to factors relating to the specific means of propagation.
Thank you in advance, Paul or others, for any elucidative information
that you may provide....
P.S. -- Sandie Markland in a recent AHS Journal article commented that
H. sieboldiana and H. tokudama species and decendant cultivars don't do
so well in containers, becoming stagnant in growth and often dimishing.
I'm wondering if there exists a list, kind of like the "sun tolerant list",
of plants that don't do that well in containers. I can tell
you, the Gaucamole trio (w/Fried Banans and Fried Green Tomotoes) does
excellently in containers, as does the parent H. 'Fragrant Bouquet'.
Is there a plan to include in the AHS database a field for "this plant
does well in containers"?
Andrew Lietzow, Plantsman http://hostahaven.com
1250 41st Street 515-274-0300 voice
Des Moines, IA 50311-2516