Hi there:
I have read through this thread multiple times to allow the terminology to sink in, and am asking someone to kindly confirm or correct my understanding: to help achieve best success with growing a mango long term here in So Cal, you either buy a tree that's an ungrafted seedling such as a laverne manilla and graft your desired type to it, or, grow your own seedling, which can serve either to fruit or a graft target. Growing your own seedling will be true to type if you get multiple growths from one seed. Yes? There are exceptions to this, of course, I'm just trying to understand the general strategy.
Thank you!
Most of what you've stated is accurate according to multiple observers. The part about multiple growths is actually related to Polyembryonism in mangoes, where one of the seedlings is often a clone of the parent. It's not always a clone, you don't always get multiple trees to sprout from seeds of polyembryonic varieties, and even if you do, there's no guarantee that one of them will be a clone of the parent. Though there are experimental techniques being employed to separate the clones from the new offspring.
In Gary Zill's case, he crushes the leaves of the different seedlings and selects for ones with different sap aromas to the parent mango, in the case of those trying to germinate clones from seedlings, they select for aromas similar to the sap aroma of the parent. In any case there are no guarantees, but it is possible to get polyploid clones as well. Polyploid clones will be dwarf versions of the parent.
It's somewhat complicated, but in practice, many will succeed at getting clones to grow from seed. In my opinion, the rigorous selection put forth by Gary Zill brought forth many superior genes, and the potential to get even better results is quite high if someone were to continue with his technique, specifically improving on his work.