What is somaclonal variation answer?
Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation. Somaclonal variation is not restricted to, but is particularly common in, plants regenerated from callus.
What are somaclonal variation What is the cause of their appearance?
External factors like growth regulators, temperature, light, osmolarity and agitation rate of the culture medium are known to influence the cell cycle in vivo in plants, considerably, which indicates that inadequate control of cell cycle in vitro is one of the causes of somaclonal variation (Karp 1994; Nwauzoma and …
What is somaclonal variation and its application?
The term somaclonal variation by Larkin and Scowcroft (1981) was given for the variability generated by the use of a tissue culture cycle. Somaclonal variation is defined as genetic variation observed among progeny plants obtained after somatic tissue culture in vitro.
How do you identify somaclonal variation?
Methods of detecting somaclonal variants
- Morphological detection.
- Physiological/biochemical detection.
- Molecular detection.
- Cytological methods.
- Proteins and isozymes.
- Restriction fragment length polymorphism.
- Polymerase chain reaction based techniques.
- Random amplified polymorphic DNA.
What is somaclonal variation example?
Rice: Plants regenerated from rice callus shows phenotypic characters. These somaclones exhibit variations such as number of tiller per plant, panicle size and frequency of fertile plant.
Why somaclonal variations are important?
Somaclonal variation is a valuable tool in plant breeding, wherein variation in tissue culture regenerated plants from somatic cells can be used in the development of crops with novel traits.
What are the factors that can induce somaclonal variations?
Characteristics for which somaclonal mutants can be enriched during in vitro culture includes resistance to disease pathotoxins, herbicides, high salt concentration, mineral toxicity and tolerance to environmental or chemical stress, as well as for increased production of secondary metabolites.
What are the factors influencing somaclonal variation?
The genetic changes associated with somaclonal variations include polyploidy, aneuploidy, chromosomal breakage, deletion, translocation, and gene amplifications, besides several mutations.
What are the types of somaclonal variation?
There appear to be two types of somaclonal variation: heritable and epigenetic. Heritable variation is stable through the sexual cycle or repeated asexual propagation; epigenetic variation may be unstable even when asexually propagated.
Who discovered somaclonal variation?
Larkin and Scowcroft
The term ‘somaclonal variation’ was first introduced by Larkin and Scowcroft (1981) to describe the variation observed among plants regenerated after passing through tissue culture or cell culture. Somaclonal variations were first recorded in potato, sugarcane, rice and maize in the 1970s and 1980s (Karp, 1995). …
What is meant by somaclonal variation?
Somaclonal variation. The term somaclonal variation by Larkin and Scowcroft (1981) was given for the variability generated by the use of a tissue culture cycle. Somaclonal variation is defined as genetic variation observed among progeny plants obtained after somatic tissue culture in vitro. Theoretically all progeny plants regenerated
How important is the source of explant for somaclonal variation?
The source of explant is very critical for somaclonal variations. For instance, potato plants regenerated from callus of rachis and petiole are much higher (~50%) compared to those regenerated from callus of leaves (~12%). In general, for many plant cultures, somaclonal variations are higher with increased duration of cultures.
What are somaclonal changes in plants?
Regenerated plants with altered chromosomal changes often show changes in leaf shape and colour, growth rate and habit, and sexual fertility. It is generally heritable mutations and persist in plant population even after plantation into the field. Basic Features of Somaclonal Variations
What do you mean by somaclones?
Somaclonal variations are dfined as the genetic variability present among cultures somatic cells. Plants derived from such cells or progeny of such plant is called somaclones.
