Hi Kevin,
Pollen will keep for several weeks, probably a few months, just in the fridge. This is how the autumn flowering plants can be crossed with the spring ones. If you want to keep it longer term it can be frozen and it will last at least a couple of years. Make sure it is dry before putting it in the fridge – just keep it in a warm, dry room for a day or two first.
Each Pleione has 4 pollinia (2 pairs) in its pollen cap and you can cut these into the 4 separate bits and use each one separately. If you want to do more crosses than 4 with pollen from the same parent, you could cut each of the 4 pollinia in half to give 8 bits. You may end up with less seed developing in any successful pods if you use just a small portion.
Paul
