Shadegardener said: ... It makes sense about the genetic variety but I wasn't sure if environmental factors had any influence on the genetics. I have such a small gardening area and I grow a lot in pots so I wasn't sure if I could squeeze in enough variety to experiment with. Thanks for clarifying.
Certainly your environment will select for traits that support survival and propagation where you live (climate, pests, diseases, soil, etc). However, with most commercial seeds, the genetic variety has mostly been bred out of them.
So starting a landrace with commercial OP or F1 hybrids is like looking for needles in a haystack, where the haystack has very few needles. You'll find that variety's
best genes for your region, but the odds are against that one variety having many extra-suitable genes.
I think that the breeding game is a numbers game: it works faster and gives more options if you're choosing the best few plants out of 1,000 plants or 10,000 plants. Picking the best plant from ten plants will go much slower, and it might be many years before you see an unusually good combination of genes.