Dry Seed Sowing

At Kingfisher Orchids we always let our phalaenopsis pods mature until the pod splits naturally.  This adds a few months to the process, but we think it is well worth it.  One advantage of dry seed is that it is easy to spread out in the mother flask.  The main advantage though is that luckily viruses do not cross the placental wall from the pod into the seed.  This means we can still use a virus infected pod parent, and produce virus free seed.  If using the green pod method, a small amount of liquid from cutting open the pod can infect the whole cross.  Even if you test for viruses, the test strips only check for the two common viruses, of which there are may more that phalaenopsis can host.

 1.  Harvest the pod once it starts to turn yellow.  Pick off any of the petals etc that are remaining on the pod.  if the pod has not split, wash it under running water and using anti-bacterial soap and a soft toothbrush, clean the exterior of the pod.  I then use 70% Ethyl alcohol on a cotton ball to sterilize the pod.  Place the pod onto a piece of clean white photocopy type paper.  Leave it there undisturbed until it splits naturally, which could be a few days.  Seed will fall onto the paper from the split pod.  Sometimes tapping the pod helps dislodge the seed as well.  

I leave my pods inside my laminar flow cabinet with a piece of paper covering the top of the pod while it matures and seed comes out. (no fan on).

 2.   The seed will look like pale yellow/brown dust.  If you hold the paper with one hand, slightly bend it up on the two sides, and tap the underneath with a pencil, the seed will kind of gather together in the bottom of the paper.  Lay the paper down onto a flat surface and start removing all of the unwanted pieces to the outside of the paper.  Sweep all of the unwanted junk like chaff off of the paper.  Pick up the paper and tap the bottom again to move the seeds into the middle of the paper.   Lay it down again and with your hand fan the surface of the paper starting up high and moving down lower until you see the last of the 'hairs' of the chaff being moved away. 

 3.    Once you have clean seed, fold the paper in half down the long edge and tap the paper to make sure all of the seed is in the crease. 

  4.   From this point you will need a couple of things, fresh 3% hydrogen peroxide, and a 12cc plastic syringe without the needle, (the kind that they use to give kids medicine).

  5.   Pull the plunger from the syringe, and pour the seed into the syringe.  Don't worry about the seed coming out of the hole, as it will stick to the walls of the syringe because of static charge from pulling the plunger out.  Pouring the seed in from the piece of paper takes a bit of skill, so I would recommend doing it over a second clean piece of paper just in case.  The problem is that the seed wants to stick to the paper, and you will have to tap the paper to get it to move down the crease.   Once the seed is inside the syringe, slowly insert the plunger so as not to blow the seed out of the end.  I usually push it almost all of the way to the end, about to the 2cc line.

  6.    The next step is to pour fresh Hydrogen Peroxide into the lid of the bottle, and add a tiny amount of anti bacterial soap to the liquid in the lid.  The soap would be about 1/8 drop or less.  Mix this around in the lid for a few seconds.  Using the syringe, draw up about 1.5cc of the liquid, and then draw in another 2cc of air.  This gives you some space to mix the seed with the Hydrogen Peroxide.   

  7.    Put one finger over the hole and shake the seeds and liquid for about 30 seconds or longer, until all of the seeds are wet.  Using a suggestion from my friend Dustin Miller, plug the hole with one finger, and pull the plunger back.  This creates a bit of a vacuum inside the syringe which aids the hydrogen peroxide in saturating the outside of the seeds.  After doing this for a few times, remove your finger and stand the syringe on the plunger end with the hole facing up.  I usually leave it for about 30 minutes to one hour, shaking occasionally.  (up to 2 hours is usually OK, but overnight doesn't work...oops!) 

  8.    When the time is up, have 3 mother flasks ready.  I use a laminar flow cabinet or a glove box, and rinse the flasks off with a 10% bleach solution.  I hold my finger over the syringe hole, and swish it around in the bleach solution as well to clean the outside of the syringe.  Once inside the sterile area, open the flask and wipe around the rim with a microfiber cloth that was soaked in the bleach solution and then wrung out.  This is where contamination is most likely to come from, and the wiping of the rim has cut my contamination to near zero.

  9.   Take the syringe and while holding it with the hole upwards, slowly expel the air with the plunger.  When the air is all gone, give the syringe a little shake to mix the seed with the liquid and then tip it down and squirt a bit into the first flask.  Care must be taken not to squirt it out too hard, otherwise it will be injected below the media surface.  I usually do it from above the flask, and on an angle so that if it squirts too strong, it will hit the side of the flask first. 

  10.   I often do 3 mothers, because if one contaminates from a piece of crap getting mixed in with the seed, the others will probably be fine.  I sometimes use different media strengths to see which one has the best growth. 

  11.  I usually have a little bit of water remaining on the surface of the medium after autoclaving.  I use this to swirl the seed around to distribute it evenly on the surface.  Also if there is some seed remaining in the syringe, just draw this water up into the syringe, give it a shake, and squirt it back into the flask.  

Place the flasks under lights supplying 75-100 Par.  Watch for contamination, and if you see a little spot forming, just open the flask in the sterile cabinet, and with a spoon scoop out the contamination and surrounding medium below it.  Leave the crater as it is, and replace the lid.