Selective Breeding for small fruits

I'm wanting to grow Mayapple and False Solomon's Seal in parts of my orchard/future food forest, partly for the sake of additional small fruit crops. I haven't found any indication that they've been bred for food cultivars, though I think I've seen a few varieties of FSS for ornamental purposes.

Does anyone know of any attempts in that direction, or made any attempts yourself?

Any other good potential small fruit crops you can think of on the forest floor? PartridgeBerry seems like an option as a ground cover, but from what I've read the berries are tasteless.

Wintergreen could be another forest floor berry.  

I'm glad you mentioned wintergreen! I'd heard of it, but dismissed it previously because it's apparently best suited to pinewoods. But then, I have a row of pines between the house lawn and the back third of my 2.5 acre lot, so... Yeah, that's probably a good fit.

Still, I'm planning to grow the other two I'd mentioned, and see if I can't improve the flavor of the FSS/treacleberry, especially.

I can't imagine a cultivated variety of mayapple being commercially viable, since a certain number of the stems in any colony are unbranched and thus produce no fruit.  Too much "wasted space," I'd think, for breeders to mess with.

Depending on how low-growing you need the plants to be, you might consider gooseberries.  Plenty of improved varieties there.  They grow and produce in the shade of the woods, but I've noticed that there is a significant yield decrease as shade increases, at least for the wild ones in our woodlot.  The bushes growing on the edge are prolific, the bushes growing a hundred feet or more in not so much.