Not really. Varieties of a species of plant have the same Latin name. Seed companies buy variety xyz. One names it king of north, another north early, another Hoosier, all the same.
Just wanted to thank @digitS' for talking about Pak Choy and posting pictures. I ordered seed, got them in a little late, but got several salads from them. They are all bolting now, but we like them and I will plant them again. Thanks Steve!
Radishes are annuals in my garden, @lcertuche . However, I have never grown a daikon or any winter radish.
I saved seed of a "Russian White" for a good number of years. If I can locate that seed, I'll need a fresh, 2017 supply. It doesn't have that typical hair on its leaves so I was using it in stir-fries. Then, I learned that the hair disappears with cooking of any of the varieties.
Radish seed is very easy to save. I've tried that sort of thing with several brassicas, including biennial Scotch kale. Still easy to save seed.
My problem with seed saving is with the species that readily cross. Isolation may be possible and I've done that but it can be awkward. Don't need many plants, tho.