Some mutagens and their effects:

Some mutagens and their effects are given below;

1.X- rays: Gene and chromosome aberrations.

2.UV light: Structural distortion of DNA.

3.Mustard gas: Guanine in DNA replaced by other bases.

4.Cyclamate: Chromosomes aberrations.

Role of mutation in evolution:

1.Mutation provides raw material for organic evolution.

2.Natural selection operates on mutation to bring about divergence in population.

3.Good mutants retain in the population while others are rejected. i.e. survival of fittest.

4.Various new plants of desired characters have been created using mutation.

Application of mutation

• It is useful in improving certain specific characteristics of a well-adapted high yielding variety. This is particularly useful in floricultural crops which are mostly clonally propagated. These crops show highly heterozygous nature and therefore, in such a case, mutagenesis is the only method available to improve the specific characteristics of clones without changing their genetic makeup.
• Inductions of desirable mutant alleles which may not be present in the normal population or germplasm or may be present but may not be available to the breeder due to political or geographical reasons.
• Mutation breeding can also be used on F1 hybrids or progenies resulting from inter-varietal crosses. These may be treated with mutagens in order to increase genetic variability by inducing mutations and to facilitate recombination among linked genes.
• Irradiation of inter-specific (distant) hybrids has been done to produce translocations.

Achievements in Mutation breeding

a) Increased in yield

b) High tillering

c) Reduced in plant height

d) Resistance to pathogen/pests

e) Earlier maturity

f) Seed quality improvement

g) Photoperiod insensitivity

h) High tillering

i) Stress tolerance

j) Wider adaptation

k) Easier harvestability and threshability