For those living in colder climates or where access to seeds is the only source of plant material, poly seeds may be the way to go.
I recommend planting your poly seeds and keeping all sprouts and raising your tree as a multi trunked tree growing in close proximity. If they twist around each other and autograft, let them be. By keeping all sprouts, we avoid the entire confusing issue of which sprout is the clone. Stakeholders on both sides of the arguements have presented conflicting information and I have come to the conclusion that genetic markers are probably the only reliable 100% guaranteed way of determining which is the actual clone.
For the backyard grower, anything less than 100% accuracy is a waste of time in my opinion if you are after an actual clone of the original tree as you don't want to waste time if you selected the wrong seedling. With the technique of keeping all clones, you must ensure that you have at least two sprouts coming from different segments of the seed.
If two or more sprouts come out of the same section of seed, there is a possibility they are simply multiple shoots from the same seed.
In colder climates, planting poly seedlings may have the added advantage that it will not likely flower in the first couple years. This is a huge benefit for those of us wanting a larger tree that is more established before it begins to flower and fruit.
I currently have projects going for LZ, Sweet Tart and Coconut Cream. I prefer these ultra sweet varieties because I feel that even if they are not grown in ideal condition such as not full sun, poor nutrition, etc..., even if they do not reach their full potential of 25%Brix or higher, I would still be happy with their flavor at 20% Brix.
Simon