I've seen this before a few times. Could be:

• Drought stress. Plants in the "silique filling stage" need more water than usual.
• Extreme temperature (too hot). Causes pollen lethality.
• Propylene glycol exposure. If your growth chamber has a coolant leak, that causes sterility too.

Given that you have new flower buds, I don't think it's temperature since those would wilt/die. My hunch is coolant leak. Do other folks have the same issue with their plants in that space?

So, check the setting in your growth room/chamber, especially for coolant leaks.

Have you checked the pollen under a microscope? I'm guessing the anthers will be undersized and/or not making much if any pollen.

If you want to get really fancy, try cross-pollinating with any other variety that is making pollen. Success would support the idea of "Environmentally based pollen lethality".

If you want to get really fancy (and the WT plants have any pollen), add some Alexander's Stain to look at viability.

Good luck!

Katie A S Burnette

Thank you for you answer.

I'm the only one using the growing chamber. Interesting, some plants do fill the silique, but other dont.

I would like to know how can one discover a coolant leak. Can you please share previous experiences?

We found the coolant leak because there was a pink liquid dripping from the ceiling of the growth room.

Are you 100% sure the plants are wild type? Are the ones with full siliques the same age/growth stage as the ones that have poor seed-set?

I'm actually using seeds collected from other person, so I'm not 100% sure. But plants from the same seed batch are behaving differently. I think it may be something to do with the light conditions (a pink light), since plants from the same batch of seed are ok under a white light.

Thank you

Now that is an interesting phenomenon!

I was wondering about the pink in the picture, assumed it was just the paint on the walls.

Check out the pollen

I will. Thank you!!