Pollen and anthers

Having some success getting pollen and some setbacks. Some roses that are supposed to be decent pollen producers (i.e. Graham Thomas has been a pollen parent for a number of roses) do not seem to produce loose pollen. I looked at the anthers of another rose with a field microscope (30X), and though they looked like they had pollen on their surface it wasn’t released to be free. Any “simple” suggestions on how to free up this pollen?

Thanks in advance.

You could try to crush the dried anthers… I have the same problem with Fragrant Plum.