Majority of miniature conifers are propagated by grafting, even the tiny dwarfs. There are a few that do root from cuttings and I have heard of a few being produced by meristematic tissue culture. But vast majority of named cultivars are from grafting.
A well done graft that is fully healed, will be almost invisible.Sadly this is not common. With dwarfs and miniatures, often the root stck always grows fater than the scion, leaving a zone of abrupt taper on the trunk if well done, leaves a permanent ugly bulging scar on poorly done grafts.
No mater how pricy and ''purty'' the tree, you need to look at the trunk. Sometimes you get lucky and find a good one. Its always worth looking.
With genetic dwarfs and witches brooms, these miniature cultivars often are difficult choices for bonsai because of their slow growth rates. If a miniature only grows (for example) one inch a year, it will take forever to rebuild foliage after styling a tree. When styling a genetic dwarf, choose your style so that you don't need to build foliage to fill an empty space if at all possible. If you cut back to minimal foliage, with the plan to rebuild large parts, you can end up waiting years or even a decade to get the foliage you wanted.
But the tiny needles and other traits of these miniatures do make them worth trying, especially for Shohin.
Personally in my mind I try to focus on cultivars that can grow at least 4 inches per year. But that is because I'm too impatient to mess with anything slower.
By the way ''witches brooms'' are not genetic dwarfs in the traditional DNA sense. They usually occur because of epigenetic changes. Changes in the protiens surrounding the DNA rather than the DNA strands themselves. Occasionally witches brooms will revert back to normal form. Majority of witches brooms are pretty stable, But this is why they two terms are not interchangeable.
