Re:Discussion on Origin of Sports.
Regards variegation in hostas, I think we need to accept the fact that
there are probably different types of variegation. There are types
like Northern Mist and Spilt Milk that are not L1-L2 histogenic layer
It's also safe to say that some typical variegation, either edged or
center, is due to chloroplast mutations. The question is, is the rate
at which chloroplast mutations occure in hostas significently
different from other genera? I don't have an answer to this question.
I've grown probably 250,000 Stella De Oro daylilies over the last 16
or 17 years and I've found three variegated plants, all of which were
mericlinal chimerals. One did revert to an all yellow-green form, but
it just couldn't grow well and eventually died. The other two never
converted to a periclinal chimeral and were eventually lost. I've
also seen some variegated mericlinal seedlings and I've seen
variegated plants from other growers. For some reason, establishing a
periclinal chimera from a mericlinal chimera in daylilies appears to
be difficult. However, given the fact that so many hostas are being
propagated, it's not unreasonable to get some variegated plants from
time to time via chloroplast mutations.
As Vaugh indicated, these variegated plants will show maternal
inheritance. If the L2 layer is white or yellow, then you should get
mostly white or yellow progenies from selfing or crossing, with a few
green ones from egg cells derived from the small amount of L1 tissue
that may be involved in gamate formation. The problem I have with
Vaugh's study is that he uses VERY few hostas and his seedling
population is VERY low. This doesn't necessarily make his conclusions
erroneous, but you can't take that data and say that all L1-L2 layer
variegated hostas are due to mutated chloroplasts.
My problem is that I haven't seen the overwhelming maternal
inheritance in the seedlings I've grown. However, I'm not claiming
that I have made any reasonable study of this yet to my satisfaction.
I need to get more data over time before I can make any reasonable
statement. Last year I grew quite a few Great Expectation seedlings
and they were about 50:50 for green:yellow. I didn't make any attempt
to save any of the yellow ones. Two years ago I grew out quite a few
Juno OP seeds and they were mostly yellowish, poor growing seedlings,
but there were also some non-yellow ones. I tried to save some of the
deeper yellow ones, but they didn't make it. Even the chloroplyll
pigmented ones weren't the most vigorous, and the color varied quite a
bit. However, one seedling is kind of nice. When these seedlings
bloom I'll intermate them and backcross them to June as both pod and
pollen parent and see what I get. I'll also intermate the GE
seedlings and backcross the better ones to GE as both pod and pollen
parent. I also grew out OP seed from September Sun and they were
about half yellow and half green. There was one white centered
variegated plant. This variegated seedling along with some of the
other seedlings I have should provide me with some interesting
material to work with. However, it will take time. I also have
several seedlings from two years ago that germinated variegated and
I'm hoping they may bloom this year. They could be Zephyr seedlings
as I did collect a few pods from Zephyr, but they got mixed in with
all the other pods that year.
Now, having said that, we still have a problem of how to explain how
its possible to get periclinal chimera seedlings. According to
Charlie Purtymun Zephyr can produce up to 85% variegated seedlings and
interestly, Zephyr seedlings also produce a high percentage of
variegated seedlings. Last year Charlie had a flat of Zephyr
seedlings growing and I would say off hand 15% of them were
variegated. I can't see how you can explain these kinds of results
from mutated chloroplasts.
Got to get this off to the digest mode.
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