# Mutation

> A mutation is a change in a plant's DNA sequence, arising in seed or in one branch (a somatic mutation); mutations are rare and usually neutral.

- Canonical: https://genetixbay.com/knowledge/glossary/mutation.html
- Also written: mutations, mutant, somatic mutation, bud sport, genetic mutation
- Glossary category: Genetics and breeding · Evidence: Supported
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

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](https://genetixbay.com/knowledge/glossary/allele.md) frequencies across seed generations.
- **Somaclonal variation**: changes from [tissue culture](https://genetixbay.com/knowledge/glossary/tissue-culture.md) [regeneration](https://genetixbay.com/knowledge/glossary/re-veg.md).
- **Epigenetic change**: altered [gene](https://genetixbay.com/knowledge/glossary/gene.md) 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](https://genetixbay.com/knowledge/glossary/genetic-drift.md); see [clone-only preservation](https://genetixbay.com/knowledge/breeding/clone-only-preservation.md).

## Related terms

[Somaclonal variation](https://genetixbay.com/knowledge/glossary/somaclonal-variation.md), [Genetic drift](https://genetixbay.com/knowledge/glossary/genetic-drift.md), [Topophysis](https://genetixbay.com/knowledge/glossary/topophysis.md), [Allele](https://genetixbay.com/knowledge/glossary/allele.md), [Clone-only](https://genetixbay.com/knowledge/glossary/clone-only.md)

## Read more

- [Clone-only cuts and how to preserve them](https://genetixbay.com/knowledge/breeding/clone-only-preservation.md)

## Sources

1. Adamek K, et al. 2022. Accumulation of somatic mutations leads to genetic mosaicism in cannabis. The Plant Genome 15(1):e20169. https://doi.org/10.1002/tpg2.20169