Sowing Seed Is Easy
C
Fred Bergman
ongratulations! You have seed from your own
cross; now you must decide about getting it sowed.
You can have someone do it for you or you can sow
it yourself. There really is no reason you cannot sow your
own seed. Most seed sowing problems are the result of in-
correct information. I first attempted sowing orchid seed
in 1949, an effort that continued without success for four
years. The only sowing directions I could find at that time
were in the book American Orchid Culture by Edward A.
White. He covered seed sowing and included the formula
for Knudson’s Solution B within only three pages.
At first, my repeated sowings failed to produce a clean
culture. To help identify the source of contamination, I
designed and constructed a seed-sowing system. It was
built around a double-ended autoclave and a glove box—
laminar air flow hoods had not yet been developed. Later,
my contamination source was found to be seed purchased
from a Florida grower. The seed was so contaminated that
a clean culture was impossible. The problem was indicated
by clues uncovered during the successful sowing of my
own crosses.
To locate some common seed sowing errors, take a close at
my sowing procedure. Try to understand what I do and the
reason I do it. How do I sow and is it a better way? What I
do is not the only way, but simply my way. In this example,
I am sowing six different crosses. I still use the original
glove box, a system that is available and convenient. I use
a prepared (only add water) media. I have tried many and
settled on Vacin & Went or Hill’s. Flasks containing me-
dia fitted with loose rubber stoppers and a cotton plug are
placed in the autoclave. Also placed in the autoclave is a
wire basket containing accessory equipment including six
funnels pre-fitted with filter paper and covered with foil.
The autoclave is operated at 18-19 psi for 30 minutes and
allowed to cool overnight. The autoclave with a door on
each end permits loading outside and unloading inside af-
ter sterilization. Everything is sterile at the time it enters
the glove box. Seed is disinfected outside the box using 2ml
bottles that are loaded, capped, and shaken occasionally
for 20 minutes. The bottles are immersed in a 10% bleach
solution. I also rinse my rubber gloves and wet the sleeves
used to protect my arms from a UV light. The autoclave is
opened using the inside door and the glove box floor cov-
8
ered with a sterile towel. The bottles containing the seed
are transferred to the box using a glove port. Inside the
box, a funnel with filter paper is placed in an empty flask
and a seed bottle emptied in the funnel. A flask is moved
into the glove box and the rubber stopper is removed and
placed back into the autoclave. After draining, the seed re-
tained on the filter paper is washed with a stream of water
and the funnel moved to a media-containing flask. A hole
is punched in the bottom of the filter paper and the seed
washed into the flask using a small volume of water. The
stopper is replaced and the flask returned to the autoclave.
This procedure is repeated until all the crosses have been
sown. Total time in the glove box sowing six crosses is sev-
en to eight minutes.
Sowing dry seed (not green-capsule) allows you to ac-
cumulate multiple crosses and sow them at one time. The
glove box, U