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Unformatted text preview: ro conditions.
Induced mutation contributes to genetic variability
by increasing DNA polymorphism. Mutagenesis disturbs
the normal biological composition, and there are 2 effects
of ionizing radiation on the heredity material: gene
mutations and chromosome breaks (Atak et al., 2004;
Dhakshanamoorthy et al., 2011). Generally, the presence or
absence of RAPD bands is used to estimate the diversity of
the samples. The disappearance of bands and appearance of
new bands from the plants exposed to gamma irradiation
could be compared to the control. The disappearance
of bands may be related to the occurrence of molecular
events such as DNA damage, point mutations, genomic
and chromosomal rearrangements, and deletions and
insertions of sequences induced by gamma radiation. The
appearance of new bands could be attributed to mutations
caused by point mutations or by the insertion or deletion
of sequences. Thus, both of these result in the alteration of
DNA, which leads to greater changes and polymorphism in
the RAPD patterns of gamma-ray–treated plants (Atienzar
and Jha, 2002; Dhaksh...
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- Spring '14