Tuesday, August 19, 2008

Contents of an Orchid Seed Pod

This is a phalaenopsis seed pod that recently split on its own. Fortunately I found it before it sent its charges to the wind and there was plenty of seed remaining. The pod was only about 5 months, but the seeds are a nice straw color, which suggests that they are ripe and viable. I didn't inspect them any more than that though. the remnant of the pod is there on the left. It is still very green as you can see. The contents come easily out, maybe with just a little coaxing.

The fluff shown here is what remains of the pollen tubes. It serves just like the silks you see on corn. In the photo you can see there is a darkened area of the fuzz, which is where there are seeds trapped in the matrix. To give them "the red pill" and free them from the matrix, I just grasp them in the forceps and rap sharply on the metal. They fall free easily onto the paper.

Here you can see the fuzz is free of seeds now.

And finally below, my nice crop of seeds ready to be sterilized and plated on a nice, rich media.

Dry seed sowing has some challenges. A split pod allows a chance for fungal spores to get into the seeds. Spores are rather difficult to kill. So as an added measure with dry seed I use the trick of soaking the seeds 8-16hrs in a mild sucrose solution with a little wetting agent. This can encourage the spores to germinate, essentially bringing them out of their protective shell, making them much easier to kill with a quick, low concentration bleach application (I use 7% of a high strength bleach (~6 or 6.15% hypochlorite) for 7min). This is followed by several washes with sterile distilled water and then the seeds are ready to plate on media. Too high a concentration or too long an exposure will kill the seeds, so you have to balance between the best sterilization you can get with the least collateral damage.

2 comments:

swamprad said...

Cool! I have read that setting a seed pod can exhaust a plant, and may stunt its growth or at least prevent it from flowering next year. Have you found that to be the case in your experience?

SapphireChild said...

I would say that like most biological systems, it depends on a number of factors.

(1) The approximate level of maturity of the plant (as in number of leaves or growths, and root mass)

(2) The relative natural vigor of the plant (maybe also related - the type of plant)

(3) Environment & care.

In my limited experience, I have seen some plants that sulk after carrying a pod, but by the same token I've had some that actually made new buds while hanging a pod.

With Paphs (in case that's whats on your mind), I usually would prefer to see the plant have more than one fan of leaves before breeding it. Dead ones don't count! :) They have to be active ones. And in most cases I wouldn't us a phal on its first blooming, but maybe on its second.