What are the causes of somaclonal variation?
Somaclonal variation can be of two sorts: Genetic (i.e. heritable) variability – caused by mutations or other changes in DNA. Epigenetic (i.e. non-heritable) variability – caused by temporary phenotypic changes.
What is somaclonal variation and factors affecting it?
Somaclonal variations occur as a result of genetic heterogeneity (change in chromosome number and/or structure) in plant tissue cultures. This may be due to: Somaclonal variations due to transposable elements, mitotic crossing over and changes in the cytoplasmic genome have also been reported.
What is somaclonal variation explain?
Somaclonal variation is defined as genetic variation observed among progeny of plants regenerated from somatic cells cultured in vitro. In addition to the basic genetic implications of this phenomenon, the variation has proven useful in breeding programs of various crop plants.
Why is somaclonal variation 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 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. In addition, wide variation in seed fertility and plant height were noticed.
How do you identify somaclonal variation?
Morphological markers usually are used to identify species, genera and families in germplasm collections. Somaclonal variants can be detected easily by morphological characteristics, such as plant height, leaf morphology and abnormal pigmentation [68].
How is somaclonal variation induced?
Generation of somaclonal variations is attributed to genetic and epigenetic modifications in DNA. In particular, transposable elements (TEs) are one of the causes of genetic rearrangements in in vitro culture. Tissue culture is reported to activate silent TEs, resulting in somaclonal variations [3].
What is somaclonal variation and its application?
This article throws light upon the five applications of somaclonal variations. The five applications are: (1) Production of agronomically useful plants (2) Resistance to diseases (3) Resistance to abiotic stresses (4) Resistance to herbicides and (5) Improved seed quality.
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.
How is selection made for somaclonal variants?
Selection for herbicide resistant phenotypes among the somaclonal variants has also been made. The herbicide is generally added to the cell culture system and the regenerated plantlets showing the tolerance to herbicide are selected.