Induced Mutation
A mutation is any change in a DNA sequence that can be
passed from parent to offspring. By inducing mutations,
scientists have been able to increase genetic variation,
which breeders depend on to produce crops with desirable
traits, such as resistance to diseases and insects.
Unlike recombinant DNA techniques, induced mutation does
not add any foreign genetic material into the plant.
Essentially, it produces results that could have
occurred through naturally occurring mutations and
selection of desirable progeny. However, as mutations
occur naturally at low frequencies and randomly in the
DNA, it would require much more time to achieve such
results.
Mutations can be induced in a variety of ways, such as
by exposure to ultraviolet or ionizing radiation or
chemical mutagens.
Since the 1950s, over 2,000 crop
varieties have been developed by inducing mutations to
randomly alter genetic traits and then selecting for
improved types among the progeny.
Many common foods,
such as popular red grapefruit varieties, are the result
of induced mutations. Recently, methods have been
developed to allow scientists to efficiently identify
and select for mutations in specific genes.
This is
enhancing the utilization of induced mutation in plant
breeding, as changes in genes known to produce specific
results can be identified rather than having to screen
very large populations of plant to find the rare
individuals with the desired trait.
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