Abstract:
Seed priming is one of the
methods that can be taken to counteract the
adverse effects of abiotic stress, also Seed
priming treatments have been used to reduce
the damage of aging and invigorate their
performance in many crops. Objective of
this study was to evaluation the effect of
gibberellin on germination characteristics
and antioxidant enzymes of safflower seeds
after aging. Experimental design was a
factorial one with complete randomized
design with three replications. The first
factor was priming by gibberellin (0 and 50
ppm) and non-primed seeds (control) and
the secondary factor was combinations of
four levels of aging (0, 1, 3 and 5 days of
aging, at 43°C). The results showed that the
priming and aging effects on germination
percentage, germination index, normal
seedling percentage, seedling length, vigor
index, catalase and ascorbate peroxidase
were significant, but on mean time to
germination not significant. Results showed
that, the highest germination characteristics
such as; germination percentage,
germination index, normal seedling
percentage, seedling length, vigor index,
catalase and ascorbate peroxidase were
attained from priming by gibberellins, under
non aged conditions. Also, our results
indicated that seed aging is related to
decrease of enzymes activity and may
contribute to low seed germination
efficiency, also priming increases enzyme
activity and increases enzyme activity with
priming treatment may contribute to
improve germination characteristics. The
general decreases in enzyme activity in the
seed lowers the respiratory capacity, which
in turn lowers both the energy (ATP) and
assimilates supply of the germinating seed.
