Principles of Plant Breeding (2+1)

Somaclonal variation

It is the variation among the tissues or plants derived from the In-vitro somatic cell culture i.e. Callus and suspension culture.

Variations are of two types:

1. Gamatoclonal variation
2. Protoclonal variation

Factors effecting soma clonal variation

1. Degree of departure from organized growth.
2. Genetic constitution of the donor plant
3. Culture environment.
4. Tissue source.

Significance of somaclonal variation in crop improvement.

1. It is an important alternative for creation of variation in such crops, which are extensively propagated by tissue culture.
2. This is help full in breaking linkages between certain undesirable genes.
3. New varieties are developed in tomato, sugarcane, celery, brassica and sorghum.
4. It has greater advantage for crop improvement in apomictic and vegetatively propagated crops and also in cross-pollinated crops with narrow genetic base.
5. In India somaclonal variants of medicinal plant Citronella javaI has been released as a commercial variety B-13, which gives higher yield and oil content.
6. Pusa Jai Kisan- Brassica juncea as somaclonal variant of Varuna variety.