I believe that many hybrids will still produce viable seed, meaning that you can plant the seeds and they will grow. However, the plants that grow from those seeds may not look like the parent plant that produced the seed. Some hybrids may also produce sterile seeds, meaning they won't even grow. Some hybrids won't even produce seeds, which makes it easy. Doesn't help much, does it.

Martha

Check out the database on the link.
Remy

Here is a link that might be useful: Plant Cultivars That Come âTrueâ (or not) From Saved Seed