In heirloom seeds, how much genetic diversity is left? Can you selectively breed the line to what grows best in your climate or have they already been bread to near identical genetics?
This is a complicated question to answer. For inbreeders like tomatoes and beans, there is very little genetic diversity left in heirloom varieties. They don't "adapt" very much from a conventional breeding perspective. Where there is some flexibility is in epigenetics. These are small changes that a plant can make in expression of genes to adapt to a given environment. Tomatoes in particular show epigenetic changes for adaptation to temperature extremes.
For outbreeders like corn, there is some room for selection, but it is usually limited by the years of selection that have gone into the variety. In other words, the more diversity has been reduced by inbreeding, the less adaptable the resulting plants become.
Thanks. I'm growing in Texas and working on aquaponics so I was hoping that I could selectively breed for best performers for my situation, while staying heirloom.