# Somaclonal variation

> Somaclonal variation is genetic or epigenetic change that appears in plants regenerated from tissue culture, especially from callus, making them differ from the donor plant.

- Canonical: https://genetixbay.com/knowledge/glossary/somaclonal-variation.html
- Also written: somaclonal variants, somaclonal variant, tissue culture variation, in vitro variation
- Glossary category: Genetics and breeding · Evidence: Established
- 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"

Somaclonal variation is change that arises in plants grown back from [tissue culture](https://genetixbay.com/knowledge/glossary/tissue-culture.md). It ranges from DNA mutations and [chromosome](https://genetixbay.com/knowledge/glossary/chromosome.md) changes to epigenetic shifts in [gene](https://genetixbay.com/knowledge/glossary/gene.md) activity. It is most common when plants are regenerated from callus (undifferentiated cell masses) and after many subculture cycles, and least common in shoot-tip and [meristem culture](https://genetixbay.com/knowledge/glossary/meristem-culture.md), which keeps organised tissue.

## In practice

For preservation, somaclonal variation is a risk to manage. Labs reduce it by using meristem or shoot-tip culture instead of callus, limiting the number of subcultures, keeping growth slow, and checking regenerated plants against the original, by eye and ideally by [DNA fingerprinting](https://genetixbay.com/knowledge/glossary/genotyping.md) (Monthony et al. 2021).

Some breeders in other crops use it deliberately as a source of new variation. That is not the aim when the job is to keep a clone exactly as it is.

## Don't confuse with

- **Genetic drift**: a population-level process in seed lines.
- **Topophysis**: [position effects](https://genetixbay.com/knowledge/glossary/topophysis.md) in cuttings, without tissue culture.
- **Clone decline**: almost always pathogens or care in cuttings; somaclonal variation is specific to regenerated tissue culture plants.

## Related terms

[Tissue culture](https://genetixbay.com/knowledge/glossary/tissue-culture.md), [Meristem culture](https://genetixbay.com/knowledge/glossary/meristem-culture.md), [Mutation](https://genetixbay.com/knowledge/glossary/mutation.md), [Genetic drift](https://genetixbay.com/knowledge/glossary/genetic-drift.md), [Polyploid](https://genetixbay.com/knowledge/glossary/polyploid.md)

## Read more

- [Tissue culture basics for cannabis growers and breeders](https://genetixbay.com/knowledge/breeding/tissue-culture-basics.md)

## Sources

1. Monthony AS, Page SR, Hesami M, Jones AMP. 2021. The past, present and future of Cannabis sativa tissue culture. Plants 10(1):185. https://doi.org/10.3390/plants10010185
2. 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