A mutation is a change in DNA: a single base change, an insertion or deletion, or a larger rearrangement. Mutations in reproductive cells can pass to seed. Somatic mutations arise in body cells and stay in the branch where they occur, so a cut from that branch carries them. A visibly different branch is called a sport (bud sport).
In practice
Somatic mutations do accumulate in long-lived cannabis plants. Adamek et al. (2022) found them across different parts of a single plant, producing genetic mosaicism. Most such changes are neutral; they sit in DNA that does not affect traits growers notice.
House position: a mutation does not mean a loss. Cuts from different parts of a plant can behave differently, which may or may not be mutation. Old cuts that decline are almost always carrying pathogens, not mutations. Occasionally a sport is an improvement, such as a variegated or differently coloured branch that some growers keep and propagate.
Don't confuse with
- Genetic drift: change in allele frequencies across seed generations.
- Somaclonal variation: changes from tissue culture regeneration.
- Epigenetic change: altered gene activity without a sequence change.
- Herm expression: a sex-expression failure, not a mutation in the plant.
Myth check
"Clones mutate and wear out" is not supported as an explanation for clone decline; see clone-only preservation.
