Like said earlier by TurkeyCreekTrees all MM111 is cloned.
uniformity
-However seedling tree’s that yield roughly the same size tree. Are true seedlings.
You can just plant random pips from apples. And you get seedling tree’s that you can graft.
However you can expect higher variance of eventual size and other characteristics (like disease resistance)
hybrids
-This is due to, most apples being hybrids of hybrids.
If you have multiple plants that are verry similair to eachother. Like most “wild” species. They produce “true to type” seeds. Thus the seeds yield roughly the same plant as the parants that made the seed.
For tomato’s you see this a lot. When they keep crossing (or backcrossing) similair tomato plants for a few (mostly 7+) generations. They get a true to type seed.
However if you cross 2 different (true to type) tomato’s. You get what they call a hybrid or F1 hybrid. Those all look quite similair (uniform). But their offspring will be all over the map.
How it is done with “named” seedling rootstocks like “Malus sylvestris Bittenfelder”
-The same happens with fruit rootstocks. You can make sure an true (or true-ish) to type apple tree is pollinated by the same variety (selfed or from the same true to type seed batch). And you get seedlings that are more uniform. They will still be less uniform than cloned rootstocks though.
For the cloning of fruiting varieties idea.
This is or was done with a lot of fruit. (grapes figs etc)
easy of rooting
-Not all apples or fruit species root easily. Or sucker profusly. Sometimes you can get somthing to grow on it’s own roots. Most of the time this is done by grafting on a dwarfing rootstock, and burying the graft union. Since they root to slow to get good cuttings of. And when grafted and burried it can take years to grow it’s own roots without dehydrating.
This is also why you plant the graft union above ground on dwarfing fruit tree’s. If the union is to low. Your fruiting varietie can grow it’s own roots and get larger.
Pick 8 out of 300+ options
-However grafting does not only yield a convenient way to multiple a variety. (think about it. most tree’s are chip budded or T-budded. So most tree’s completly grew from a single bud!! With 1 tree, you can produce enough buds for acres and acres of orchard)
Or pick 8 + 8 out of 300+ options
-It is also a convinient way to combine the “good” properties of 2 different plants.
When breeding plants you always have to choose between different properties. And by grafting you can breed plants, where you only pay attention to root properties. (size of tree disease resistance, adaptability to soils etc)
And breed other varieties where you ignore the root properties and only pay attention to the fruits and leafs (above ground parts) of the tree.
A lot of rootstocks are specificaly selected for their ease of rooting. You see this in pears. Most pears don’t root easy. But the clonal pyrus rootstocks do a lot better. Same for MM111. It was used above seedlings because those where hard to clone and less uniform.
This also leads most rootstock fruits to not be so great. Since they where not bred/selected for that. (although i heared MM106 was decent)
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