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Induced Mutation
A mutation is any change in DNA sequence that can be
passed from parent to offspring. Mutations occur
naturally at a low rate in all living organisms.
In
fact, mutation is one of the sources of genetic
diversity.
By inducing mutations, scientists have been
able to increase genetic variation in crop species.
Breeders depend on genetic variation to produce
varieties with desirable traits, such as resistance to
diseases and insects.
Unlike recombinant DNA methods,
induced mutation does not add any genetic material into
the species, although it can remove it by making
deletions of DNA.
To induce mutations, chemicals or
irradiation interact with internal enzymes that
replicate or repair DNA in living organisms.
Essentially, induced mutation produces results that
could have occurred naturally over much longer times
than it takes to induce such results.
Since the 1940s,
over 2,200 crop varieties have been developed by
inducing mutations to alter genetic traits and then
selecting among the progeny for improved types. For
example, semi-dwarf rice, low saturated fat sunflower
seeds, redder grapefruit and many flowers are derived
from induced mutations.
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