Depending on the species, the original tissue can be taken from the shoot tip, leaf, bud, stem or root tissue. The original tissue of the stock plant is not destroyed in the process. It is worth mentioning, that still experts have problems micropropagating specific species, like wooden plants. In micro propagation on uses the plant's protoplasts, a single cell that has been stripped of its cell wall by enzymatic treatment. A single leaf yields tens of millions of single cells.
Protoplasts tend to fuse with eachother, that leads to somatic hybridization .
Taking two protoplasts of the same species of plants with different characteristics can therefore lead to a single plant withe both characteristics. The evidence for this theoretically possible procedure is lacking yet. In gene-splicing experiments genetic material is incorporated into a cell. The bacterial cultures became synthesizers of insulin. Theoretically it would also be possible to incorporate genetic characteristics for accumulating high sugar content in a sugar maple.