Mutation , Mutation breeding in Crop improvement programe

• Mutation refers to the sudden change in Organism due to Segregation and recombination of Chromosome. These are heritable changes.

• Mutation may occur in nature or also induced by artificially The mutations that occur in somatic cells in plants are called sports.

• These mutations are very slow and do not enhance the speed of crop improvement programs.

• Mutation that is produced by artificial means called artificially induced mutation.

• The substances that are responsible for such mutations are called Mutagenic agents or Mutagens.

• Electromagnetic radiation like UV rays, X rays, Cosmic rays etc. Ionising radiation like Garbage rays  and Chemicals such as mustard gas, Phenol, formaldehyde, Ethyl methyl sulphonate etc are used to induce mutation.

• Artificial induced mutations are capable of changing genotypes and phenotypes in Plants as per the need.

• The production of new crop varieties of plants by artificially induced mutation called Mutation Breeding .

• In recent times, Mutation breeding and polyploidy breeding and is a magic tool for plant breeders for creating new varieties. .

• These new and original characters are produced whereas Hybridization and selection merely combine existing characters to form new varieties.

• Mutation breeding creates variability in self pollinated crops.Mutants are easily recognized in progeny. Mutation breeding produced  new desirable characters in plants.

• Mutation breeding is useful in those crops in which a gene for desirable improvement exists but not desirable to attain it.

• And in those crops in which breaking up of close linkage and transferring the little segment of chromosome to non homologous chromosome.

• Sharbati Sonora 64 and Pusa Lerma are two varieties of wheat produced from mexican varieties Sonora 64, Lemme Room 64 by gamma radiation.

• The discovery of dwarf mutant Dee- geo-woo-gen in Taiwan was a great achievement in the history of rice breeding.

• Several outstanding dwarf varieties of rice have been produced by using the gene of that varieties of Rice. Mutation breeding has great use in plant breeding but it has certain limitations.

• Most induced mutations are undesirable and lethal. It does not produce the readymade varieties but it creates variations from which desirable characters are chosen out.

• Mutation breeding is possible only in a few centers where irradiation facilities and trained staff are available.

• Most induced mutations are recessive and thus they have to be in double order to express phenotypically. Most mutation are not stable and may be reverted.