I bet by now, the Rice hybrids are all from their own intros or seedlings!
I, myself, most often do not list parents. I am not a white tag hanger in my gardens. Hate them fluttering around my pretty flowers! I have tried the wire method but sometimes run out. But, I use very few pollen parents each year (often the latest and greatest that i have) so pretty much know what I have used as I see the seedling. But not always. I consider my intros more good garden plants as I am more into color, hardiness, height, shape etc. There are a few though that I hope people are working with. I hardly ever work with my own plants.
