When multiplying meristem tissue in culture some protocols require the
sample to be continually agitated, if not the sample orients itself to light
and gravity and begins to differentiate into specialized tissue (it grows
into a plant rather than multiplies) My experience with stem props is as
follows: With traditional stem prop methods, as outlined in your link, you
get one to a few plants per node, and that's enough for most people. When
you look at those nodes under magnification you can see that there are often
three dormant nodal buds under the bract cover on a Phal stem. Often when
one is initiated it sends out chemicals to inhibit growth of the others.
Differences in light/temperature and media composition can determine if one
or more node buds might initiate and produce plants for you.

Wounding (as in slicing with a razor blade to expose raw meristem cells) a
node bud before sticking it into the test tube of solid media sometimes
produces little tumorous growths (callus tissue with meristem cell
proliferation mixed in) rather than new plants. About the size of a hulled
peanut these tumors can then be sliced up into many pieces and laid on solid
media where they will grow into many little plantlets each. When it works
you get ten times more plants for the same amount of effort and stem props
take a lot of time to begin with (I guess that's a relative statement. I
think it's a very labor intensive project.) In my experience, more often
than not the wounded tissue dies, and this agitates me because when it
doesn't I can get a flask or two of plants from a single node bud.

Changing the media components, the light levels or duration, or even
temperature can drastically alter what happens. The genes of the individual
sample influence how easily it goes through the process. The age of the
flower spike and the time of the year when it is cut also influences success
rates. In fact the number of breaths you take and the type of thoughts you
think while doing this work has quantum repercussion in several dimensions.

I wanted a shaker table so I could try a better method of making the callus
tissue proliferation "peanut" more reliably, and from my reading I think
this will involve agitation. And for agitation you need a liquid media and
some form of roller/shaker movement. There is a guy in my local society who
has nothing better to do than go to his test tubes every few hours for weeks
or months and shake them up by hand and for him this works to sufficiently
agitate the sample. I'd get tired of that really quickly and when
confronted with this option the price of the roller drum/shaker tables from
New Brunswick Scientific Equipment's catalog looks like the more reasonable
option although they all take my breath away. I am glad these are not the
only choices...

"K Barrett" wrote in message
news:MZ%Pb.126061$I06.1006194@attbi_s01...
OK I admit I'm an idiot dolt when it comes to stem props, but I do have
the
memory of an elephant, and my friend Ed Wright never mentioned a shaker
tables or any othe sort of table when he wrote his synopsis of stem props
for OrchidSafari http://www.geocities.com/~marylois/archiv23.html

Granted you may be doing these en masse, but even still....

K Barrett

"Pat Brennan" wrote in message
...
Hey Al,

Seems we are going down about the same route. I have been playing
around
with this for about 9 months with limited success. I found Arditti a
good
starting point but have really just been winging it once I got started.
One
thing going in our favor is that there are a couple of companies selling
premixed medias. The web site for PhytoTech NZ or Aust was helpful in
suggesting changes to the standard mult mix when using it for Phals.
Both
G&B and PhytoTech said they had someone who could help me, but in both
cases
I have been unable to reach these people (always out of country or not
in
today).

I have a shaker table so I really am not much help with the drum speed.
I
assumed the low speed unit was what you wanted until I looked at the
speed
I
run the shaker at. ( I know the speed by the sound and how the tissue
moves
in the flask and not by rpm.) Any ways I tend to run the shaker at 60
to
100 rpm. This is about the same speed I use for cloning Cats and Oncs.
Given that speed, I am not sure the tissue will roll in the culture
tubes
with the low speed drum, I would call the company before buying either.

That being said, I have not used the shaker for the last 4 or 5 months
because I was having better luck with solid media. One of the protocols
in
Arditti starts in a shaker, but quickly moves to solid media --I guess
this
is the route I have gone. Funny but I am having better luck with older
media. I get my best multiplication after a dark ring has formed around
the
tissue. I have yet to kill the tissue from the phenyols but I am sure I
will push it too long one of these days.

Currently I am learning by trial and error the size the tissue should be
before dividing and where the dividing should be done. I was losing a
fair
amount of tissue after cutting it up. I cut back on dividing and really
slowed the process down. I have yet to find a balance I am happy with
and
wonder if the freshly cut tissue should be treated with something before
being placed back on the media.

Do not be too hard on yourself when measuring your success. I have
found
that when sending Phals out for cloning, a batch of 500 plants will take
2
to 3 years before flasks are returned.

Pat

"Al" wrote in message
news
My goal is to expand my experience with stem propagation of Phals by
actually excising the node and attempting to multiply the meristematic
tissue in a liquid media but I probably won't stop there. I was
thinking
of
a roller drum because it looks neat. :-) A shaker table is probably
more
within my budget.

Are Phals orchids which like or dislike a 24 hour light cycle during
the
multiplication phase?

I have a book called Micropropagation of Orchids by Arditti and Ernst
published in 1993. It outlines research on propagation techniques for
many
orchids by genera and provides a kind of history of propagation for
most
but
I have been told several times that it is dated and newer info is
available
to augment what was compiled in this book. I don't have this newer
info
at
my fingertips or really know where to get it. :-( Anyway, dated or
not,
I
will turn to it once I assemble all the little gadgets I need for this
mad
experiment.

Thank you to everybody who offered input. If there is more to come I
will
be on the look out for it.


"Aaron Hicks" wrote in message
...

Al, you don't specify what you want to use it for, but the upper
speed is going to be way too high for tissue culture work with
orchids.

Keep in mind that some orchids don't like 24 hr/day cycles for
tumbling. Some do best with a few hours on, followed by a few hours
off.

I think there are plans on the web somewhere for do-it-yourself
rigs; ditto with eBay and Labx. Save some bucks.

-AJHicks
Chandler, AZ