Mutagenesis—A Potential Approach for Crop Improvement - Crop Improvement: New Approaches and Modern Techniques - page 154

Fig. 4.1 Different kinds of physical and chemical mutagens that are mostly used and selected
plants parts for mutagenic treatment/induction
wide use of mutated alleles in the breeding of numerous species. Mutation induction
raises the natural mutation rates 10-100 fold, expanding the opportunity to isolate a
higher number of mutants in a limited space. Today, induced mutations are ideal for
augmenting natural variation in germplasm and as an alternative to hybridization
and recombination in plant breeding. Mutations provide new starting material for
the production of new cultivars and on the other hand they offer excellent tools for
identifying new genes, for studying the nature of genes and their way of controlling
biochemical pathways (Micke et al. 1990 ). The genetic variation from mutagenesis
is different from that existing in germplasm collections or obtainable from cross-
ing as it is not yet selected by nature or man and thus contains traits which were
not favored during evolution or previous plant breeding activities. Besides, genes
for a desired trait may not be fit or may be tightly linked with undesirable genes so
that recombination through hybridization is rare or impossible. For example, genes