Mutagenesis Approaches in Plants and their Applications

Mutagenesis refers to the process of generation of mutations in DNA molecules, including chromosomal rearrangements and alterations in DNA sequence. The incidence of natural or spontaneous mutation frequency in nature is very low, and it is not sufficient for plant breeding programs to develop new varieties. Mutants were also used for gene function discovery which controls the particular phenotype. Genetic diversity was induced in plants on a good scale through induced mutagenesis programmes, and this helped to improve crops all over the world. Significant efforts have been made to develop induced mutagenized resources using physical (Fast-neutron, X-ray, and -irradiation), chemical (DEB, EMS, and MNU), and biological (T-DNA and Transposons) agents. However, mutants developed through biological agents or genetically modified organisms (GMO) face severe regulatory limitations imposed by national and international agencies to release as varieties. The most popular chemical and physical mutagenesis techniques used by breeders are EMS and gamma rays mutagens. Estimating the appropriate mutagen dose and mutagen exposure time are essential factors to develop mutagenized resources. The dosage and duration of a mutagenic treatment are determined by the species, physiological state of the species, and material handling prior to and after the mutagenic treatment. Neutrons and X-rays are powerful mutagens that cause significant chromosomal damage and have been used to create large chromosomal deletions.