Artificial mutagenesis as an aid in overcoming genetic vulnerability of crop plants.

Artificially induced genetic variation is being used effectively to supplement or complement sources of natural origin for practical plant breeding. Thus, creating genetic variation uill become increasingly important as crop genetic resources become more difficult to obtain via plant exploration. The aritificial induction of useful genetic variation offers important elements that can be used for overcoming genetic vulnerability: (1) new, previously unknown alleles can be induced in crop plant species to broaden the base of variation; (2) useful genetic variation can be induced in modern cultivars helping to shorten breeding time or to extend production "life"; (3) characteristics of existing genetic resource stocks can be improved to make them more useful in breeding; and (4) recombination in crosses may be enhanced. The performance of induced mutant crop cultivars and the successful uses of induced genetic variation in cross breeding indicate that artificial mutagenesis will play an increasingly greater role in plant breeding.