I spent a bit of time as a commercial plant breeder. Most of the stuff you find online is inaccurate. Genetics and plant breeding is extremely complicated and species specific. It's not something the average master gardener even has the fundamentals to understand.
For example the answer to your question about saving hybrid corn seed.
One plant of a F1 commercial contains the same heterogenity as a healthy 1,000 plant OP variety population. Commercial hybrids are created by crossing inbreds from separate genetic pools. This helps maintain the required genetic distance between the inbreds to maximize heterosis.
1,000 F2 plants from one F1 is enough to initiate a stable population. Saving less than 1,000 plants on the subsequent generations will create a bottleneck and the population will quickly suffer from inbred depression.
"Heirloom" varieties that are sold are poorly maintained and extensively contaminated (often exceeding 50%). So not stable at all.
In order to properly maintain them you'd need closer to 1,000,000 plants with extensive but careful rogueing over over 30 generations with extensive genetic profiling to clean them up. They are all an absolute mess at this point.
Once you got them cleaned up the same 1,000 plants could maintain the population.
I spent a bit of time as a commercial plant breeder. Most of the stuff you find online is inaccurate. Genetics and plant breeding is extremely complicated and species specific. It's not something the average master gardener even has the fundamentals to understand.
For example the answer to your question about saving hybrid corn seed.
One plant of a F1 commercial contains the same heterogenity as a healthy 1,000 plant OP variety population. Commercial hybrids are created by crossing inbreds from separate genetic pools. This helps maintain the required genetic distance between the inbreds to maximize heterosis.
1,000 F2 plants from one F1 is enough to initiate a stable population. Saving less than 1,000 plants on the subsequent generations will create a bottleneck and the population will quickly suffer from inbred depression.
Similar to what I said but you need 1000 not a couple hundred. I wonder how stable it is for heirloom varieties.
"Heirloom" varieties that are sold are poorly maintained and extensively contaminated (often exceeding 50%). So not stable at all.
In order to properly maintain them you'd need closer to 1,000,000 plants with extensive but careful rogueing over over 30 generations with extensive genetic profiling to clean them up. They are all an absolute mess at this point.
Once you got them cleaned up the same 1,000 plants could maintain the population.
I guess when I said heirloom varieties I meant those that have been used by indigenous communities for generations.